Dissertations / Theses on the topic 'Faba bean'

Bibliography: leaves 111-120. This study investigated various aspects of genetic resistance in fava beans to Ascochta blight (A. fabae) with the objective to facilitate an efficient breeding strategy for long-term control. Pathogenic variability of A. fabae was found to be high, as was genetic variation between resistant fava bean accessions. A number of alternative resistance genes to that of Ascot cultivar were identified.

Bibliography: leaves 158-176. Yield variation of faba bean in southern Australia is associated with seasonal and site variation in stress levels during podsetting and podfilling. This study examined the development of pods and seed growth in the field; quantified the effects of water stress and temperature on pod and seed development; quantified the importance of stem and podwall dry matter to seed growth and seed yield and examined the importance of genotype to these responses.

Faba bean is a significant rotation crop in northern NSW and is susceptible to drought while the reproductive structures are sensitive to high temperatures. For high yield, early sowing allows accumulation of a large biomass and avoidance of terminal stress. Trials at Breeza and Narrabri in North West New South Wales examined the influence of sowing date on yield components, maturity, pod distribution and biomass production and at Breeza the influence of irrigation was also examined. Tagged plants were used to study pod development in relationship to temperature regimes. Sowing in early May produced the highest yield and seed weight at both sites. At Breeza the latest sowing date produced greater yield than the earliest and this was associated with very high final biomass at the earliest sowing date. At Narrabri the earliest sowing date yielded similar to the latest indicating that early sowing was less detrimental to yield at Narrabri. Poor yield in late sown material is likely due to terminal stress and is more likely in less favourable locations and seasons. Poor yield in early sown material is likely due to production of excessive biomass in favourable seasons and locations. Irrigation had no impact on yield but reduced harvest index and seed weight. Lower seed weight overall was observed at the Breeza site possibly as a result of intraplant competition. The quickest maturing genotype, gave the highest yield and seed weight at both sites. Dry matter production was greater with early sowing, higher moisture and warmer temperatures. In contrast to other studies, a weak relationship between biomass and yield was observed. Production of pods was maximized with average daily temperatures in the range of 12.5 – 13.5 °C, daily maximum in the range 23.5 – 25.5 °C and daily minimum in the range of 3 – 4 °C.

Drought stress is one of the most important limiting factors for the sustainable production of faba bean (Vicia faba L). This study covered the characterization of physiological, biochemical and morphological traits that are enhancing the drought tolerance of faba bean by assessing key traits under the field and controlled environments. The investigations utilised a range of plant tissues, i.e. leaf, flower, root and grain tissue’s response under water deficit (WD) conditions. Carbon isotope discrimination was found as a suitable trait as well as predict grain yield. Large genotypic variation (16.84‰ ~ 21.96‰) among genotypes made it a potential selection tool for breeding programs. Among yield contributing characters, plant height and 100 seed weight were the most important contributors (0.60**). Hydroponic assay showed great promise and results from hydroponic assays were confirmed through a subsequent sand culture study and suggested as an effective screening platform as genotypes had a similar response under both conditions. Leaf chemistry of faba bean genotypes showed the presence of increased myo-inositol and sucrose in irrigated treatments. Comparison of water use efficiency prediction through leaf-level carbon isotope abundance and gas exchange suggested the former would be a suitable tool as a drought tolerance screening tool. The relatively small differences in carbon isotope abundance between leaf and grain suggest that either tissue are appropriate for inclusion in breeding programs. Pod formation during stress was primarily governed by the pistil. Reciprocal crosses between WD and well-watered (WW) plants showed pistil were more sensitive to drought than stamen. Finally, the grain quality of faba bean tends to be resilient and not affected by WD. Quantification of essential amino acids and major mineral nutrients in grains collected from WW and WD plants that showed no significant effect between treatments.

This investigation covered characterisation of various faba bean rust isolates by identifying a differential set in the host; identification of molecular markers linked with rust resistance genes Uvf-2 in Doza#12034 and Uvf-3 in Ac1655 and their validation across diverse backgrounds; and elucidation of the host-pathogen interactions of Uromyces viciae-fabae with faba bean, field pea (Pisum sativum), lentil (Lens culinaris), chickpea (Cicer arietinum), lupin (Lupinus albus and Lupinus angustifolius) and mungbean (Vigna radiata). The differential pathogenicity in the interaction of Vicia faba × Uromyces viciae-fabae led to the identification of nine faba bean rust pathotypes, characterised by the set of twelve genotypes (regarded as differential), and named 0-10, 0-46, 40-31, 40-55, 24-40, 63-53, 63-49, 55-63 and 63-63. This information will help faba bean breeders to carefully deploy rust resistance gene(s) which can effectively insight resistance against pathotypes of targeted environment. Genetic analysis, using pathotype 24-40, revealed monogenic inheritance of rust resistance in faba bean genotypes Doza#12034 and Ac1655, respectively. After genotyping Fiord/Doza#12034 and Fiord/Ac1655 RILs, two closely linked KASP markers KASP_Vf_0703 and KASP_Ac×F165 were mapped on chromosome III and V with Uvf-2 and Uvf-3, respectively and validated successfully in a set of local/exotic faba bean genotypes. These closely linked markers will allow breeders to implement markers assisted selection for both resistance genes. The histopathology of Australian U. viciae-fabae revealed a host range: both faba bean and field pea were competent hosts showing varietal differences to pathogen responses, with differential expression in resistance; lentil showed complete hypersensitive resistance by expressing cell death; and chickpea, lupin and mungbean appeared as non-hosts.

Faba bean is highly sensitive to heat stress during reproductive growth. Yield losses of up to 50% can be realised in Australia due to terminal heat stress; therefore, improvement for tolerance will help mitigate the losses occasioned by heat stress. This study evaluated 48 faba bean genotypes for heat tolerance in the field in northern NSW. Assessment for pollen thermotolerance using a newly developed impedance flow cytometry (IFC) protocol was also carried out. Two genotypes contrasting in their heat responses were further evaluated in field heat chambers to identify possible mechanisms of heat tolerance. Terminal heat stress effected by late sowing reduced the yields by 49–62% compared to early May sown crop, which averaged 3.65 t/ha. Lower yields in the heat-stressed crop resulted from shorter growing duration, decreased biomass production and partitioning, and lesser yield components. Podding and grain filling were more sensitive to heat stress than flowering; therefore, they will be critical in improving heat tolerance in faba bean. Pollen viability assessed through IFC was high at temperatures above 25 °C and could not be linked to lower pod set. Moreover, a study on faba bean pollen storage revealed that, pollen stored at 4–5 °C could keep for 28 days without significantly losing its viability. Low assimilates production was associated with high pod and flower abscission, which reduced yields. On the contrary, high yields were associated with taller plants, high PAR interception and normalised difference vegetation index, and better photosynthetic efficiency. Adaption to heat stress in northern NSW will be driven by maintaining a longer grain filling duration, early biomass production and high efficiency in partitioning to pods and seeds.

Environmental stresses are serious concerns in faba bean. Therefore, matching phenology to the environment is a key to improving adaptation and increasing yields. Experiments were conducted to evaluate the effect of sowing dates on plant phenology, frost, pod set, biomass distribution, yield and its components in faba bean. Field experiments with three sowing dates and a glasshouse experiment at Narrabri, New South Wales, Australia, plus a field experiment at Dirab, Saudi Arabia, were conducted to achieve these objectives. Early sowing resulted in early flowering, late maturity, high yield, longer seed filling duration, the highest number of leaf nodes and the tallest plants. Grain yields decreased with the delay in sowing in 2015 (4.56, 3.92 and 1.59 t ha-1), while sowing II gave the highest yield in 2016 (2.16, 2.91 and 2.29 t ha-1) because sowing I was highly affected by chocolate spot (Botrytis fabae). Amongst the yield components, seed weight plant-1 was the most important contributor (r = 0.7***); it was also the most affected by biotic and abiotic stresses. Frost tolerance differed among the growth stages and also during each stage. For example, the five-leaf stage was more sensitive to frost than younger and older stages. Despite the faba bean being an indeterminate crop, the flowers that formed at the beginning of flowering had higher percentage (41.1−42.5%) of pod set and faster pod formation (14−15 days) than later flowers indicating frost occurrence at this stage could cause high yield loss. Finally, the current studies concluded that, sowing faba bean at Narrabri from the last week of April to the first week of May was ideal, but sowing earlier may increase yield if rust and chocolate spot can be controlled. We recommended genotypes IX486/7-6, 11NF010a-2 and IX561f-4-2 as cultivars due to their distinct characteristics and yield above 3.1 t ha-1, which was greater than the popular varieties, such as PBA Nasma (3 t ha-1) and PBA Warda (2.9 t ha-1).

[Truncated abstract] Faba bean (Vicia Faba L.) ranks third worldwide in overall production among coolseason legume crops and is used as a main source of protein both for food and feed purposes in many parts of the world. Australia is a major exporter of faba beans and the price received depends on the quality of the seed especially colour of the seed coat. Consumers don?t like faba beans that are dark coloured or that have blemishes on the seed coat. Environmental staining and storage discolouration deteriorate seed colour causing substantial economic losses to growers and grain handlers. To investigate the influence of environmental conditions, especially during pod/seed development and maturity, on the degree of environmental staining, field trials were conducted using four faba bean varieties (Fiord, Fiesta, Ascot and Cairo) in a range of environmental conditions under the Mediterranean-type climate of south western Australian grain belt. Although a majority of seeds had good colour but 3-25% were stained up to an unacceptable level across the trials and this varied with location and variety. Seeds formed later in plant development (located on the upper nodes of the plant) were more stained than seeds formed earlier (located on the lower nodes). This may be due to end of season environmental factors, such as high temperature and light intensity, and water and nutrient stress. Similarly seeds formed on small and weak plants, which may have developed under stressful conditions, had more staining than seeds formed on normal sized and healthy plants. Genotypic variation was also evident with Fiord showing greater staining than Ascot, Fiesta and Cairo. The cause of environmental staining appears to be complex but was associated with phenolic contents. Storage discolouration was influenced by a number of factors including temperature, seed moisture content, light and storage period and these were critical in determining storage life. ... Faba bean hardness, examined by the hard-to-cook test, also increased with increased storage temperature. There was a high negative correlation (r2 = 0.98) between storage temperature and cooking ability of faba bean. There was a three-fold increase in lignin content of faba bean stored at 50°C compared to those stored at 5°C and it was correlated with bean hardness (r2 = 0.98). Reduction in free phenolics was negatively correlated (r2 = 0.75) with bean hardness. The environmental staining in faba bean can be minimized with correct choice of varieties, robust agronomic practices to establish and maintain healthy plants and the use of mechanical graders and colour sorters. For minimizing storage discolouration faba beans must be dehydrated to ≤12% seed moisture content and stored in insulated bins (silos) or at least bins painted white and constructed under trees shades. In addition occasional flushing with N2 will further help reduce the colour darkening. The above approaches will improve quality, market opportunities, price and hence profitability of faba bean in the farming systems.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: The dry matter (DM) production and chemical composition of whole crop faba beans (Vicia faba) and oats (Avena sativa) were determined according to fresh material harvested at weekly intervals. From 75 to 166 days after planting whole plants of faba beans and oats were harvested at a height of ca. 10 cm above the ground on five randomly selected areas of 0.25 m² each. The freshly harvested material was weighed “as is” and ovendried to determine the DM content of each sample. The fresh and DM forage production per hectare was then calculated. The crude protein (CP), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), nitrogen free extract (NFE), fat (EE), calcium (Ca) and phosphorus (P) contents were determined according to standard laboratory techniques. The change in chemical composition of fresh whole crop material was regressed on days after planting using simple linear regressions. The fresh and DM production of whole crop faba beans and oats increased with advancing growth stage. During the 2002 production year fresh yield production of both whole crop faba beans and oats peaked at 131 days (44.7±6.9 and 28.4±7.1 ton/ha respectively). DM yield peaked at 159 and 152 days for whole crop faba beans and oats being 9.4±1.3 and 8.8±0.7 tons DM/ha respectively. The chemical composition of both forage crops decreased with advancing growth stage. The CP content of whole crop faba beans decreased (P<0.05) from 25.3% at 82 days after planting to 18.4 % at 166 days after planting in the 2002 production year, while during the 2003 production year the CP content of whole crop faba beans decreased (P<0.05) from 28.2 to 19.5 % from 75 to 159 days after planting. During 2002 the CF % of faba beans increased from 20.2 to 22.6%, while during 2003 CF % similarly increased from 21.8 to 26.5%. The CF % for oats during 2003 increased from 25.6 to 36.9%. During the same time the EE, Ca and P contents also decreased (P<0.05), while the NDF, CF and ADF contents increased (P<0.05). Two milk production studies were conducted to compare the feed intake, milk yield and milk composition of Holstein cows receiving either whole plant faba bean silage or oats as a hay or silage. Faba bean (Vicia faba) silage (FBS) was compared to that of cows receiving either oat (Avena sativa) hay (OH) or oat silage (OS) and in a 50:50 combination with FBS. Faba beans (cv. Ascot) and oats (cv. Sederberg) were planted on a Glenrosa soil. Whole crop faba beans were ensiled 145 days after planting in an above ground concrete bunker using a commercial bacterial inoculant after being wilted for one day. In the first experiment, total mixed rations (TMR) containing FBS, OH or a 50:50 mixture of FBS and OH as forage, together with a concentrate, were fed to three groups of seven lactating Holstein cows each. The experiment was conducted according to a randomized block design. Cows were on average 112±44 days post calving producing 24.0±6.2 kg milk/day. Milk production parameters of cows receiving diets containing different forages were compared by analysis of variance. The DM intake and milk yield of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OH as forages did not differ (P>0.05), milk yields being 18.9±1.9, 20.6±1.3 and 20.5±1.4 kg/cow/day respectively. With the exception of MUN, milk composition parameters did not differ among treatments (P>0.10). Cows fed OH as roughage source had a higher (P=0.06) MUN level in the milk. Results from this study indicate that FBS could effectively replace OH in lactating dairy cow diets. In the second experiment, total mixed rations (TMR) containing FBS, oat silage (OS) or a 50:50 mixture of FBS and OS as forages, together with a concentrate, were fed to six Holstein cows according to a double 3 x 3 Latin Square cross-over experimental design. Each cow received 13 kg DM either FBS, OS or a 50:50 mixture of FBS and OS were fed as forages, together with three different concentrates at nine kg “as is” each, to each cow. Cows were on average 108±30 days post calving producing 22.0±2.0 kg milk/day. DM intake, body weight, milk yield and milk composition parameters of cows receiving diets containing different forages were compared statistically. The DM intake and body weight of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), although body weight changes differed significantly (P<0.10), i.e. 4.0±3.2, 8.8±3.2 and -6.0±3.2 kg respectively. The milk yield of cows receiving TMR’s containing FBS, OS or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), milk yields being 22.8±0.4, 21.4±0.4 and 21.9±0.4 kg/cow/day respectively. Of the milk composition parameters, the milk CP(%) of cows fed TMR’s containing FBS differed (P<0.05) from the cows fed the 50:50 mixture of FBS and OS, as well as cows fed the OS, being 2.82±0.02, 2.93±0.02 and 2.96±0.02% respectively. Results from this study indicate that FBS could effectively replace OS in lactating dairy cow diets. The South African database on in situ protein and fiber degradability values for whole crop faba beans and oats is limited. The chemical composition of whole crop faba beans and oats constantly change as plants mature. For optimal stage of ensiling and feed formulation it would be useful to have CP, NDF and ADF degradability values available for whole crop faba beans and oats harvested at different growth stages. The objective of this study was to determine the ruminal nutrient degradabilities of whole crop faba beans (Vicia faba) and oats (Avena sativa). Whole crop faba beans and oats were cut at weekly intervals from 75 to 159 days after planting. Effective DM, CP, NDF and ADF degradability values of faba beans and oats harvested at 117, 131, 145 and 159 days after planting were determined by using the in situ nylon bag technique. Three non-lactating Holstein cows fitted with ruminal fistulae were used. Plant material put into Dacron bags was incubated in the rumen for 4, 8, 12, 24, 48, 72 and 96 hours. The degradability of DM, CP, NDF and ADF fractions of whole plant faba beans and oats in four different growth stages (117, 131, 145 and 159 days from planting) did not differ (P<0.05) among cows. The degradability of different fractions for both roughages were affected (P<0.05) by growth stage and incubation hours. DM, CP, NDF and ADF disappearance of whole crop faba beans and oats at 117 and 159 days after planting differed (P<0.05) at 4, 8, 12, 24, 48, 72 and 96 hours of incubation time. The DM, CP, NDF and ADF disappearance values were fitted to the non-linear model p = a + b (1- e-ct). The effective degradabilities (P) could be calculated using a fractional outflow rate of k = 0.05. For whole crop faba beans, parameter b (potentially degradable fraction) and parameter c (the rate at which b is degraded) all differed different forages were compared by analysis of variance. The DM intake and milk yield of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OH as forages did not differ (P>0.05), milk yields being 18.9±1.9, 20.6±1.3 and 20.5±1.4 kg/cow/day respectively. With the exception of MUN, milk composition parameters did not differ among treatments (P>0.10). Cows fed OH as roughage source had a higher (P=0.06) MUN level in the milk. Results from this study indicate that FBS could effectively replace OH in lactating dairy cow diets. In the second experiment, total mixed rations (TMR) containing FBS, oat silage (OS) or a 50:50 mixture of FBS and OS as forages, together with a concentrate, were fed to six Holstein cows according to a double 3 x 3 Latin Square cross-over experimental design. Each cow received 13 kg DM either FBS, OS or a 50:50 mixture of FBS and OS were fed as forages, together with three different concentrates at nine kg “as is” each, to each cow. Cows were on average 108±30 days post calving producing 22.0±2.0 kg milk/day. DM intake, body weight, milk yield and milk composition parameters of cows receiving diets containing different forages were compared statistically. The DM intake and body weight of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), although body weight changes differed significantly (P<0.10), i.e. 4.0±3.2, 8.8±3.2 and -6.0±3.2 kg respectively. The milk yield of cows receiving TMR’s containing FBS, OS or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), milk yields being 22.8±0.4, 21.4±0.4 and 21.9±0.4 kg/cow/day respectively. Of the milk composition parameters, the milk CP(%) of cows fed TMR’s containing FBS differed (P<0.05) from the cows fed the 50:50 mixture of FBS and OS, as well as cows fed the OS, being 2.82±0.02, 2.93±0.02 and 2.96±0.02% respectively. Results from this study indicate that FBS could effectively replace OS in lactating dairy cow diets. The South African database on in situ protein and fiber degradability values for whole crop faba beans and oats is limited. The chemical composition of whole crop faba beans and oats constantly change as plants mature. For optimal stage of ensiling and feed formulation it would be useful to have CP, NDF and ADF degradability values available for whole crop faba beans and oats harvested at different growth stages. The objective of this study was to determine the ruminal nutrient degradabilities of whole crop faba beans (Vicia faba) and oats (Avena sativa). Whole crop faba beans and oats were cut at weekly intervals from 75 to 159 days after planting. Effective DM, CP, NDF and ADF degradability values of faba beans and oats harvested at 117, 131, 145 and 159 days after planting were determined by using the in situ nylon bag technique. Three non-lactating Holstein cows fitted with ruminal fistulae were used. Plant material put into Dacron bags was incubated in the rumen for 4, 8, 12, 24, 48, 72 and 96 hours. The degradability of DM, CP, NDF and ADF fractions of whole plant faba beans and oats in four different growth stages (117, 131, 145 and 159 days from planting) did not differ (P<0.05) among cows. The degradability of different fractions for both roughages were affected (P<0.05) by growth stage and incubation hours. DM, CP, NDF and ADF disappearance of whole crop faba beans and oats at 117 and 159 days after planting differed (P<0.05) at 4, 8, 12, 24, 48, 72 and 96 hours of incubation time. The DM, CP, NDF and ADF disappearance values were fitted to the non-linear model p = a + b (1- e-ct). The effective degradabilities (P) could be calculated using a fractional outflow rate of k = 0.05. For whole crop faba beans, parameter b (potentially degradable fraction) and parameter c (the rate at which b is degraded) all differed v significantly (P<0.05) between four different growth stages (117, 131, 145 and 159 days from planting) of plant maturity for CP, NDF and ADF. In oats, parameter b and parameter c did not differ (P>0.05) between the four different growth stages (117, 131, 145 and 159 days from planting) of plant maturity. Results from this study could make a valuable contribution towards the South African databases on faba bean and oats nutrient values and can be used in dynamic feed formulation. Faba beans cut as fresh crop or silage may in the foreseeable future play an increasingly larger role in the feeding of dairy cattle in the Winter Rainfall Region of South Africa. As in the case of lupin silage, though with much higher protein content, farmers will be able to produce their own quality and high protein roughage. The nutritive properties of faba bean silage holds great promise as a forage in lactating dairy cows.
AFRIKAANSE OPSOMMING: Die droëmateriaal (DM) produksie en chemiese samestelling van heelplant fababone (Vicia faba) en hawer (Avena sativa) is bepaal deur vars plantmateriaal op ‘n weeklikse basis te sny. Plantmonsters van beide fababoon en hawerplante is gesny vanaf 75 tot 166 dae na plant op ‘n hoogte van ca. 10 cm bo die grond. Plantmonsters is weekliks gesny op vyf ewekansige persele met ‘n oppervlak van 0.25 m² elk. Die vars gesnyde plantmateriaal is geweeg en daarna ge-oonddroog om die DM inhoud van elke monster te bepaal. Die varsmateriaal en DM opbrengs per hektaar is bereken. Die ruproteïen (RP), ruvesel (RV), neutraal bestande vesel (NBV), suur bestande vesel (SBV), stikstof vrye ekstrak (NVE), eterekstrak (EE), kalsium (Ca) en fosfor (P) inhoud is bepaal volgens standaardlaboratorium metodes. Lineêre regressie is gebruik om die verandering in chemiese samestelling van heelplant fababone en hawer te kwantifiseer. Vars en DM produksie van heelplant fababone en hawer het toegeneem met toename in groeistadium. Gedurende die 2002 produksiejaar het varsmateriaal opbrengs vir beide fababone en hawer gepiek op 131 dae (44.7±6.9 en 28.4±7.1 ton/ha respektiewelik). Heelplant fababoon en hawer DM opbrengs het gepiek op 159 en 152 dae na plant op 9.4±1.3 en 8.8±0.7 ton DM/ha, respektiewelik. Die chemiese samestelling van beide gewasse het afgeneem met toename in groeistadium. Die RP inhoud van heelplant fababone het verminder (P<0.05) van 25.3% op 82 dae na plant tot 18.4% op 166 dae na plant vir die 2002 produksiejaar, terwyl gedurende die 2003 produksiejaar die RP inhoud verminder (P<0.05) het vanaf 28.2 tot 19.5% vanaf 75 tot 159 dae na plant. Gedurende die 2002 produksiejaar het die ruvesel % van fababone toegeneem vanaf 20.2 tot 22.6%, terwyl gedurende die 2003 produksiejaar het die ruvesel toegeneem vanaf 21.8 tot 26.5%. Die ruvesel % vir heelplant hawer het vir die 2003 produksiejaar toegeneem vanaf 25.6 tot 36.9%. Vir dieselfde tyd, het EE, Ca en P inhoud ook verminder (P<0.05), terwyl NBV, RV en SBV inhoud toegeneem (P<0.05) het. Twee melkproduksiestudies is uitgevoer om die effek van fababoonkuilvoer op voerinname, melkopbrengs en melksamestelling van Holsteinkoeie te bepaal. Fababoonkuilvoer (FBKV) is vergelyk met behulp van koeie wat hawerhooi (HH) of hawerkuilvoer (HKV) en in ‘n 50:50 kombinasie met FBKV as ruvoere ontvang het. Fababone (cv. Ascot) en hawer (cv. Sederberg) is gevestig op ‘n Glenrosa grond. Heelplant fababone is gesny en ingekuil op 145 dae na plant. Gesnyde materiaal is toegelaat om vir ‘n dag te verlep, waarna dit in ‘n bogrondse kuilvoersloot ingekuil is met behulp van ‘n kommersiële bakteriële entstof. In die eerste eksperiment is volvoere met FBKV, HH en ‘n 50:50 mengsel van FBKV en HH as ruvoer, saam met ‘n konsentraat, gevoer aan drie groepe koeie wat bestaan het uit sewe Holsteinkoeie elk. Die eksperiment is uitgevoer volgens ‘n ewekansige blokontwerp. Koeie was gemiddeld 112±44 dae in melk en het 24.0±6.2 kg melk/dag geproduseer. Melkproduksie-veranderlikes van koeie wat diëte ontvang het met verskillende ruvoere is met ‘n variansie-analise vergelyk. Die DM inname en melkopbrengs van koeie op volvoere bevattende vii FBKV, HH of ‘n 50:50 mengsel van FBKV en HH, het nie betekenisvol verskil (P>0.05) nie. Melkopbrengs was 18.9±1.9, 20.6±1.3 en 20.5±1.4 kg/koei/dag, respektiewelik. Met die uitsondering van melkureumstikstof (MUN), het melksamestelling-veranderlikes nie betekenisvol (P>0.10) verskil tussen behandelings nie. Koeie wat HH as ruvoer ontvang het, het ‘n hoër (P=0.06) MUN vlak in die melk gehad. Resultate van hierdie studie dui daarop dat FBKV effektief HH in lakterende melkkoeidiëte kan vervang. In die tweede eksperiment is volvoere, betsaande uit FBKV, hawerkuilvoer (HKV) of ‘n 50:50 mengsel van FBKV en HKV as ruvoer, saam met ‘n konsentraat aan ses Holsteinkoeie gevoer volgens ‘n dubbel 3 x 3 Latynse Vierkant omskakel proefontwerp. Elke koei het 13 kg DM van FBKV, HKV of ‘n 50:50 mengsel van FBKV en HKV ontvang as ruvoere, saam met drie verskillende konsentrate van 9 kg op ‘n natuurlike vogbasis elk. Koeie was gemiddeld 108±30 dae in melk en het 22.0±2.0 kg melk/dag geproduseer. DM inname, liggaamsmassa, melkopbrengs- en melksamestelling- veranderlikes van koeie op verskillende diëte wat verskillende ruvoere ingesluit het, is statisties vergelyk. Die DM inname en liggaamsmassa van koeie op volvoere bevattende FBKV, HKV of ‘n 50:50 mengsel van FBKV en HKV, het nie betekenisvol (P>0.10) verskil nie. Verandering in liggaamsmassa het betekenisvol (P<0.10) verskil, te wete 4.0±3.2, 8.8±3.2 en -6.0±3.2 kg, respektiewelik. Die melkopbrengs van koeie op volvoere bevattende FBKV, HKV of ‘n 50:50 mengsel van FBKV en HKV as ruvoer, het nie verskil (P>0.10) nie. Melkopbrengs was 22.8±0.4, 21.4±0.4 en 21.9±0.4 kg/koei/dag, respektiewelik. Ten opsigte van die melksamestelling-veranderlikes van die koeie op die onderskeie volvoere, was dit slegs melk RP(%) van koeie wat volvoere met FBKV ontvang het, wat betekenisvol (P<0.05) verskil het van die koeie wat HKV en die 50:50 mengsel van FBKV en HKV as ruvoer ontvang het. Melk RP(%) was 2.82±0.02, 2.93±0.02 en 2.96±0.02%, respektiewelik. Resultate van hierdie studie dui daarop dat FBKV effektief HKV in lakterende melkkoei diëte kan vervang. Die Suid-Afrikaanse databasis van in situ proteïen- en veseldegradeerbaarheidswaardes vir heelplant fababone en hawer is beperk. Die chemiese samestelling van heelplant fababone en hawer verander gedurig soos plante toeneem in ouderdom en groeistadium. Vir optimale stadium van inkuiling en voerformulering sou dit belangrik wees om DM, RP, NBV en SBV degradeerbaarheidswaardes van heelplant fababone en hawer ge-oes op verskillende groeistadiums te hê. Die doel van die studie was om die ruminale degradeerbaarheidswaardes vir heelplant fababone en hawer te bepaal. Effektiewe DM, RP, NBV en SBV degradeerbaarheidswaardes is vir fababone en hawer bepaal vir groeistadiums 117, 131, 145 en 159 dae na plant deur gebruik te maak van die in situ nylon sakkie tegniek. Drie nie-lakterende Holsteinkoeie elk toegerus met ‘n rumen- kannula is gebruik om ruminale degradeerbaarheidswaardes te bepaal. Plantmateriaal wat in Dacron sakkies afgeweeg is, is in die rumen geplaas vir 4, 8, 12, 24, 48, 72 en 96 ure. Die degradeerbaarheid van DM, RP, NBV en SBV fraksies van heelplant fababone en hawer vir vier verskillende groeistadiums (117, 131, 145 en 159 dae na plant) het nie betekenisvol (P<0.05) tussen koeie verskil nie. Die degradeerbaarheid van verskillende fraksies van beide ruvoere het verskil (P<0.05) tussen groeistadiums en inkubasie-ure. DM, RP, NBV en SBV verdwyning van heelplant fababone en hawer op 117 en 159 dae na plant het betekenisvol (P<0.05) verskil by 4, 8, 12, 24, 48, 72 en 96 inkubasie-ure. Die DM, RP, NBV en SBV verdwyningswaardes is gepas op ‘n nie-lineêre model p = a + b (1- e-ct). Die effektiewe degradeerbaarheid (P) kon bereken word met ‘n fraksionele uitvloeitempo van k = viii 0.05 vanuit die rumen. Vir heelplant fababone het parameter b (potensieel degradeerbare fraksie) en parameter c (die tempo waarteen b degradeer word) betekenisvol verskil (P<0.05) vir alle groeistadiums (117, 131, 145 en 159 dae na plant) vir degradeerbaarheidswaardes van RP, NBV en SBV. Vir hawer het parameter b en parameter c nie betekenisvol (P>0.05) tussen die vier verskillende groeistadiums (117, 131, 145 and 159 dae na plant) verskil nie. Die resultate van hierdie studie kan ‘n belangrike bydrae maak tot die Suid-Afrikaanse databasis van fababoon en hawer voedingswaardes, en kan aangewend word in dinamiese voerformulering. Die gebruik van varsgesnyde of ingekuilde heeplant fababone kan in die toekoms ‘n al groter rol speel in melkkoeivoeding in die Winterreënstreek van Suid-Afrika. Soos in die geval met lupiene, maar met ‘n hoër proteïen inhoud, sal produsente hul eie kwaliteit en hoë proteïen ruvoer kan verbou. Die voedingswaarde van fababoonkuilvoer hou groot belofte in as ruvoer vir lakterende melkkoeie.

Field and glasshouse experiments were carried out at the Plant Breeding Institute, Narrabri (PBI) to study the drought tolerance of faba bean, identify the quantitative trait loci (QTLs) for flowering time and assess the response to genotype by environment interaction. The result of the field study showed that the early season (ES) genotypes accumulated higher biomass, set more pods and had longer pod-fill duration, and produced higher grain yield than the late season (LS) genotypes. Four ES (11NF014b-1, IX474/4-12, PBA Nanu, and PBA Nasma) and two LS (PBA Samira and PBA Ranu) genotypes selected from the field study when evaluated under glasshouse conditions revealed that the ES genotypes had a conservative water use and stomatal conductance, and had 50 % reduction in transpiration at a higher fraction of transpirable soil water compared to the LS genotypes. Thus, it was concluded that the escape and avoidance mechanisms were the underpinning mechanisms of drought tolerance in faba bean. Based on the above results, the genetics of flowering time and related traits were studied in the Fiord/Doza#12034 derived recombinant inbred lines. The result showed that days to first flowering (DF), days to 50 % flowering (D50F), days to maturity (DM), and the node on which the first flower appeared (NFFA) were governed by 2, 2, 4, and 2 genes, respectively. Composite interval mapping identified two consistent QTLs for DF, D50F, NFFA and two minor QTLs for DM on five genomic regions. One pleiotropic QTL for DF and D50F linked to C231883-32.0 was mapped on chromosome 8 that could be used in marker-assisted selection program. Evaluation of faba bean breeding lines at Breeza and PBI for two years identified four genotypes (14NF612a-62, PBA Nanu, IX561/4-2-3 and 14NF618a-53) with high yield and moderate stability that can be used for improving yield in faba bean.

The extensive and continual use of herbicides in cropping situations has inevitably led to the phenomenon of "herbicide-resistance" in weeds and this has become one of the most challenging issues in modern agriculture. Herbicide-tolerant crops (HTC) were introduced to diversify weed management practices, but the lack of integrated weed management strategies, along with the continuous use of the same herbicide mode of action (MOA) demanded by the HTC has continued to impose selection pressure on weeds to evolve with herbicide resistance. Consequently, this thesis has been focused on the introduction of herbicide MOA combinations into HTC systems in an attempt to reduce the rate of herbicide resistance evolution in weeds. Raphanus raphanistrum is the number one broadleaf weed in Australia, and for this case study, the newly released ALS-inhibiting imidazolinone tolerant faba bean cultivar PBA Bendoc with its conventional cultivar, PBA Samira, were selected as the study species. ALS-inhibiting (imazamox + imazapyr and imazethapyr) and PSII-inhibiting (metribuzin) herbicides were used as the two herbicide MOAs. The herbicide sensitivity of R. raphanistrum was initially evaluated at different growth stages, in glasshouse studies using herbicide-resistant and susceptible biotypes to ALS-inhibiting herbicides. The highest susceptibility was observed at the earliest growth stage regardless of the biotype and Imazamox + imazapyr proved to be more effective in controlling both biotypes compared to imazethapyr. The same two herbicides were tested on faba bean cultivars at different growth stages to assess crop tolerance and identify the herbicide application window. The field trials conducted in 2018 and 2019 showed increased ALS-inhibiting herbicide tolerance in PBA Bendoc compared to PBA Samira even at the most advanced growth stage. Both faba bean cultivars were then evaluated for their tolerance to metribuzin in-crop application at different herbicide rates. Both cultivars responded similarly, showing progressive herbicide damage with increasing application rates. However, the reduced pod number, even at the lowest rate used, flagged the possible yield penalties that may result in using in-crop metribuzin applications. It is thus suggested that metribuzin must be used post sowing pre-emergent (PSPE) respecting the label recommendations. The potential herbicide combinations were then tested on herbicide-resistant R. raphanistrum and PBA Bendoc to evaluate their efficacies. Metribuzin was initially used as PSPE in all combinations, and was to be followed by imazamox + imazapyr applications at the same growth stages of the weed and the crop as in previous experiments. However, 100% control of R. raphanistrum was achieved using metribuzin alone, and thus no second herbicide was required. All the assessed herbicide combinations were tolerated by PBA Bendoc, proving the suitability of these herbicide combinations for incorporation into the PBA Bendoc cropping system. These results led to two potential herbicide combination strategies: (i) herbicide rotations, with metribuzin as PSPE in one year along with another potential herbicide MOA in the following year, (ii) herbicide sequential application, with metribuzin applied at PSPE and imazamox + imazapyr applied at the 2-4 leaf stage if R. raphanistrum plants survived the metribuzin treatment. A seed germination study was conducted under different temperature/photoperiods, pH levels, osmotic potentials, salinity and burial depths to identify the optimal germination conditions for R. raphanistrum. The optimum germination conditions for both herbicide-resistant and susceptible biotypes of R. raphanistrum were found to be 25ºC/15ºC temperature range under 24 hours complete dark. However, the significant interaction between photoperiod and temperature indicated that the seed germination under higher temperatures is less favoured by 24 hours dark conditions regardless of the biotype. An increased moisture stress tolerance in herbicide-resistant seeds was observed, whilst both biotypes reacted similarly to different pH levels and burial depths. In summary, this thesis has elucidated the effectiveness of two herbicide MOAs in controlling R. raphanistrum while addressing the crop tolerance to these herbicide MOA combinations. These findings will help in setting up stewardship guidelines to be used with the PBA Bendoc faba bean cultivar to mitigate the misuse of herbicides, thus ensuring their sustainable application. In addition, the demonstration of differential seed germination requirements of resistant and susceptible R. raphanistrum seeds has provided further information to help with its systematic management. Overall, this study can be used as a case study to investigate herbicide options that can be used in different HT crop cultivars to control a range of weed species.
Doctor of Philosophy

Faba bean (Vicia faba Roth) is grown worldwide as a protein source for food, used for animal feed, and is a common cover crop in Europe, but is underutilized in Midwest farming systems. Faba bean, field pea (Pisum sativum L.), and forage pea were evaluated for biomass and chemical composition when sown after wheat. Faba bean, forage pea, balansa clover (Trifolium michelanium Savi), red clover (T. pratense L.), and rye (Secale cereale L.) were evaluated similarly when intersown into maize. Cover crops after wheat had no significant biomass differences, averaging 1210 kg ha-1, enough to support 1.5 animal unit month (AUM) ha-1 for a 450 kg cow with calf. Rye yielded the greatest (374 kg ha-1) of the intercrops with faba bean averaging similarly and other intercrops averaging significantly less. Intercrops did not affect maize yield. Faba bean has similar potential as other commonly used cover crops in the Midwest.

The presence of stem nematodes (Ditylenchus spp.) is a principle reason for rejecting faba bean seed for further cultivation and processing for human consumption. In the UK, annual faba bean yield losses due to the stem nematodes are estimated at between £400k and £4m per annum. A further estimated £6.25m is lost to the industry over 5 years due to the withdrawal of infested land from faba bean cultivation. Since chemical nematicides are not available and crop rotation is impractical due to the polyphagy of stem nematodes, only plant resistance offers a cost-effective and environmentally benign means of control. The present study investigates the species status of stem nematodes on faba bean in the UK in order to evaluate the level of resistance in both commercial cultivars and previously identified resistant sources of faba bean. For the first time this study has shown that D. gigas n. sp. is the predominant stem nematode species in the UK faba bean. Development of various screening methodologies has led to the efficient selection for stem nematode resistance in faba bean germplasm. Increased susceptibility was observed in spring sown genotypes, as shown by high reproduction of stem nematode, greater stem swellings and lesions. It has been demonstrated that virulence of D. gigas n. sp. increased with repeated reproduction on the susceptible genotype. Conclusively environmental conditions are shown to influence stem nematodes incidence in faba bean seeds. Increased stem nematode infestation within seeds was more pronounced in cool and humid years. This work established the differences in gene structure of endo-β-1,4-glucanases in D. gigas n. sp. and D. dipsaci sensu stricto, which are known to be a cell-wall degrading genes. Complex host-pathogen interactions have been shown by increased relative expression of dg-eng gene in planta of susceptible and resistant genotype. In continuation from this project the selected faba bean genotypes are being used in developing new cultivars with resistance to D. gigas n. sp. Understanding of the stem nematode parasitism process in relation to the development of novel approaches for control of stem nematodes is discussed.

[Truncated abstract] Soils of Western Australian cropping regions are very low in phosphorous. White lupin, chickpea, and faba bean are being increasingly used in rotations with wheat on these soils. Yield of wheat after a legume crop is frequently higher than its yield after wheat. It has been reported that in addition to nitrogen, legumes can also contribute to improve the availability of phosphorous for the subsequent crops. This PhD research project aimed at optimising the economic returns of wheat-legume rotations through more efficient use of P fertiliser in the legume phase as well as enhanced availability of soil P in the subsequent wheat phase

Les nanovirus sont des virus de plantes, multipartites, à ADN simple-brin circulaire, qui se répliquent dans le noyau de cellules infectées par le mécanisme de cercle roulant. Ils dépendent de protéines de leur hôte pour la réplication, seule la protéine M-Rep codée par le virus, est requise pour initier la réplication du génome du nanovirus. Dans le but d’élucider les interactions moléculaires entre la protéine M-Rep et des protéines de l’hôte, nous avons obtenu plusieurs versions de M-Rep du nanovirus Faba bean necrotic yellows virus (FBNYV) étiquetée avec six histidines, afin de permettre sa purification par chromatographie d’affinité. La protéine M-Rep étiquetée est capable d’initier, dans les tissus végétaux, la réplication de l’ADN qui la code et celle d’autres ADN du virus. Le réplicon codant pour cette protéine étiquetée se propage dans Vicia faba infectée par le FBNYV. De plus, il est transmis par l’insecte vecteur Aphis craccivora à partir de plantes infectées. L’interaction in planta entre les protéines M-Rep étiquetée et M-Rep sauvage a été montrée. D’autre part, j’ai mis en évidence que la protéine M-Rep étiquetée est phosphorylée in vitro par des kinases de la plante. Enfin, l'infection d’Arabidopsis thaliana par le FBNYV, en utilisant l'insecte vecteur A. Craccivora a été établie. Nous avons démontré que le FBNYV est capable de se multiplier et d’induire des symptômes dans certains écotypes d’A. Thaliana
Nanoviruses, multipartite single-stranded DNA viruses of plants, multiply in the nucleus of infected cells by rolling circle replication. They rely on host proteins for viral DNA replication, only the viral encoded M-Rep protein is required for initiation of replication of their genome. To enable the study of interactions between M-Rep and viral or host factors involved in replication, we designed oligohistidine-tagged M-Rep protein of the nanovirus Faba bean necrotic yellows virus (FBNYV) that allow its affinity purification from plant tissue. The tagged M-Rep protein is able to initiate replication of its cognate and of other FBNYV DNAs in Nicotiana benthamiana leaf discs and plants. The replicon encoding the tagged M-Rep protein multiplies and moves systemically in FBNYV-infected Vicia faba plants. In addition it is transmitted by the insect vector Aphis craccivora from infected plants. Using the tagged M-Rep protein, the in planta interaction between wild-type M-Rep and its tagged counterpart is demonstrated. Furthermore, I present data showing that a recombinant oligohistidine-tagged M-Rep of FBNYV is phosphorylated in vitro by plant kinases. Finally, infection of Arabidopsis thaliana by FBNYV using the insect vector A. Craccivora was established. Susceptibility of several A. Thaliana ecotypes to FBNYV was studied

La fava (Vicia faba L.) è una leguminosa, ad alto contenuto proteico, usata nell’alimentazione umana e zootecnica. Nonostante il valore di questa coltura, l’area coltivata a fava è andata diminuendo nel corso degli ultimi anni. Questo è dovuto sia al fatto che la resa della coltura è instabile e vincolata a diversi fattori biotici ed abiotici, sia alla presenza di fattori antinutrizionali che riducono gli usi possibili di questo legume. Abbiamo identificato 51 linee inbred a basso contenuto di tannini, che sono state caratterizzate fenotipicamente con 22 caratteri fenotipici, stabiliti dall’UPOV (International Union for the Protection of New Variety of Plant procedure) per la caratterizzazione di fava. Le analisi di similarità mostrano che, fissati i caratteri di interesse (basso contenuto in tannini, assenza di fattori antinutrizionali, alto livello di auto-fertilità), c’è comunque una grande variabilità nella popolazione, che può essere sfruttata per la creazione di nuove varietà. Mediante un test di valutazione in campo, condotto con lo schema sperimentale Augmented Block Design, sono stati identificati i migliori genotipi, allo scopo di sviluppare nuove varietà sintetiche. Sono state create 7 nuove sintetiche triplo bianco (TW), che sono state testate, a livello preliminare, in campo per due anni. Una selezione delle migliori linee inbred e sintetiche è stata valutata in ambiente controllato, per la resistenza a due delle principali patologie di fava: Ruggine e Muffa grigia. Tre linee inbred, IS28, IS48 (entrambe TW) e IS89 hanno una buona risposta a entrambe le malattie; IS-Sint4 ha ottenuto il miglior risultato tra le sintetiche. Questo lavoro, quindi, ci ha permesso di identificare e caratterizzare alcune linee inbred e sintetiche che potranno essere una valida alternativa alle varietà esistenti sul mercato, con particolare attenzione alla stabilità della resa e al basso contenuto di fattori antinutrizionali, i principali obiettivi di breeding di questa specie.
Faba bean is a high-protein legume crop that is widely used in human feeding and livestock feed. Despite its value, the global area under faba bean cultivation has decreased over the last five decades. Not only its production is constrained by several biotic factors and abiotic stresses, but also the presence of anti-nutritional factors reduces the use of this legume. We have indentified 51 inbreed lines with a low tannin content, that have been phenotypically characterized by examining 22 traits, as provided by the UPOV (International Union for the Protection of New Variety of Plant procedure) guidelines for faba bean. The similarity analysis shows that even if some interesting traits (low tannin, absence of anti-nutritional factors, high level of self-fertility) have been fixed, a great variability is present in the population, fully exploitable to obtain new varieties. A performance assessment on the field and a comparison between the lines through the experimental scheme of Augmented Block Design, have been performed to identify the best genotypes for the development of new synthetic varieties. Seven new synthetic varieties were created, with the characteristics of the triple white (TW), that have already been tested in the field for two years. Furthermore, a selection of synthetic lines and of best inbred lines of the population were tested, in controlled conditions, for resistance to two major diseases that affect the faba bean: Rust and Chocolate spot. Three inbred lines, IS28, IS48 (both TW) and IS89 with a good response to both diseases have been identified. The best of the Synthetic lines tested it is IS-Sint4. The work has allowed us to identify and characterize some inbred lines and synthetic, which will be multiplied, evaluated and developed in order to create a new commercial variety that could be a viable alternative to existing varieties, with a focus on yield stability and low content of anti-nutritional factors.