Intraspecific Variation in Mean Endosperm Cell Cycle Time in Vicia faba (L.) and Interspecific Hybridization with Vicia narbonensis (L.)

The rate of early embryo-sac development was studied in seven faba bean (Vicia faba L.) cultivars grown in a controlled environment. The embryo-sac stage was determined from the number of endosperm nuclei per embryo-sac and the number of embryo cells during the first 12 days after pollination. Differences in early embryo-sac development were observed between the genotypes studied. In addition, five different V. faba×V. narbonensis crosses and reciprocals were made using genotypes with small differences in mean endosperm cell cycle time and genotypes with large differences. The percentage of success (pod set) in V. faba×V. narbonensis crosses ranged between 9 % and 59 % while in the reciprocals it ranged from 12 % up to 30 %. However, cytological studies showed that the high percentage of success (pod set) observed in the cross A-107 × A-202 was not associated with a higher percentage of interspecific hybrid embryos. The results indicate that genotypes of the two species with smaller differences in mean endosperm cell cycle time result neither in a higher percentage pod set nor in bigger hybrid embryos.     

Interspecific hybridization between Vicia faba (L.) and Vicia narbonensis (L.): Early pod growth and embryo-sac development

Summary Fertilized embryo-sac development and pod growth was studied in one Vicia faba cultivar, one Vicia narbonensis population and their reciprocal crosses. The initial development of endosperm and embryo was at least four days faster in V. narbonensis than in V. faba. Pods and ovules developed also faster in V. narbonensis than in V. faba. The growth rate of the hybrid pods followed the growth rate of the mother species, but was slower than that of the pods from selfed flowers. In the cross V. narbonensis × V. faba the ovules stopped growing 9 days after pollination, while in the reciprocal cross they stopped growing 15 days after pollination. Hybrid embryo-sacs from V. faba × V. narbonensis were aborted before they reached the stage of 256 endosperm nuclei or 200 embryo cells. Selfed V. faba embryo-sacs reached this stage in less than 9 days after pollination. In the reciprocal cross the embryo-sacs were aborted before they reached the stage of 128 endosperm nuclei or 80 embryo cells. Selfed V. narbonensis embryo-sacs reached this stage at the 4th day after pollination. Given that at these stages the embryo has less than 200 cells it was concluded that an in-ovule embryo culture technique should be developed to obtain hybrid plants.     

Early Embryo-Sac Development in Faba Beans (Vicia faba L.)

Cuphea viscosissima Jacq. is an herbaceous annual dicot indigenous to the U.S. This species is being developed as a new oilseed crop and commercial source of medium-chain fatty acids (MCFAs). In this paper, the phenotypes and genetics of the mcm-1 and cpy-1 mutations of C. viscosissima are described. These mutations affect the percentages of fatty acids of seed storage lipids. They were induced by treating seeds with 0.04 M ethyl methanesulfonate for 5 h. Observed segregation ratios for these mutations were not significantly different from expected ratios for codominant genes. The mcm-1 mutation eliminates 95.0 % of wildtype MCFAs — caproic (C6: 0), caprylic (C8: 0), and capric (Cio: 0) acid percentages are decreased from 0.8 to 0.0 %, 20.7 to 0.5 %, and 68.6 to 6.7%, respectively. The cpy-1 mutation decreases C6: 0 and C8: 0 from 0.9 to 0.0 % and 19.8 to 3.9 %, respectively, whereas it increases C12: 0 and C14: 0 from 2.2. to 14.3 % and 0.8 to 7.4 %, respectively.     

Electrophoresis of the Seed Proteins of Vicia faba L. and Its Immediate Progenitors — A Reappraisal

Electrophoretic patterns of total seed protein analyzed by polyacrylamide gel electrophoresis under non-dissociating and dissociating conditions were found to have diagnostic value for the Vicia species. The close similarity in the seed protein profiles of the cultivated species and Vicia narbonensis narbonensis indicated that this last species can be considered as the immediate progenitor of V. faba. The study also indicated that V. serratifolia should be included as a subspecies in V. narbonensis. The broad bean, Vicia faba, is one of the most important leguminous pulses cultivated over a wide range (from Central Asia to Western Europe and from Ethiopia and Sudan to Scandinavia). Schultz -Motel (1972) was the first to identify remains of V. faba seeds from archeological sites of the Bronze Age, mainly from Central and Southern Europe. Recently, Kislev (1985) found charred seeds of horsebean (V. faba L.) from the 7th millennium B.C. Thus, horsebean should be included among the legumes grown by some early Neolithic people. Zohary and Hopf (1973) have suggested that the wild ancestors of V. faba are species belonging to section Faba. In particular, the French vetch V. narbonensis L., was the promosing candidate; most probably, because the area of distribution of V. narbonensis coincides with that of V. faba. On the other hand, Ieibe (1934), Ladizinsky (1975), and Abdall and Gunzel (1979) refuted the reports that V. narbonensis (and wild species from the section Faba) may be considered as immediate ancestors of the cultivated species of V. faba. These authors reported on the albumin profile of seed protein in Vicia. This study aims to reassess the relationships between V. faba and its taxonomically related species in terms of their storage protein profiles and present some information on the evolution of V. faba.     

The Influence of Day Length on Plant and Nodule Development of Fababeans (Vicia faba L.) and Grasspeas (Lathyrus sativus L.)

The valuation of the influence of different day length (DL) on plant and especially nodule development of fababeans ( Vicia faba L.) and grasspeas ( Lathyrus sativus L.) was the aim of these experiments. For that, experiments in growth chambers (Exp. 1) with DL of 10, 13, 16 and 19 hours and an experiment in vegetation boxes (Exp. 2) with DL of 7, 10, 13 hours and natural DL as control (CON) were conducted. The development of plants was studied by 6 and 7 harvests (HA) respectively beginning at 27 and 31 days after emergence (DAE) respectively, as well as consecutive determinations of leaf area, dry matter (DM) of the different plant organs and nodule number.
Total- and pod-DM of both species increased with higher DL (19 h, CON). Nodule-DM was positive influenced by longer assimilation duration and bigger leaf areas of the higher DL treatments. With onset of pod ripening, which occurred early under higher DL, lower nodule-DM was determined due to the beginning of nodule senescence. Under 19 h DL the fababeans established highest nodule-DM, 1,100 mg/plant, whereas the grasspea 410 mg only. Nodules under shorter DL (7 h, 10 h) showed less intensive red tissue and less nodules > 6 mm diameter. The grasspea established more bigger nodules than the fababeans. Total nodule number was not unequivocal affected by DL, however, it increased with the course of vegetation. Senescence of nodules was most evident at time of highest growth rates of the pod-DM.     

Components of Seed and Straw Yield in Common Vetch (Vicia sativa L.)

178 common vetch (Vicia sativa L.) strains were tested for 2 years under dryland conditions in Bursa, Turkey. Broad-sense heritability of the traits was calculated for each trait. Phenotypic and genotypic correlation coefficients between seed and straw yield, with several morphological and reproductive traits, were obtained. Broad-sense heritability estimates were high for 1000-seed weight and number of seeds per pod. Heritability values for both seed and straw yield were small and insignificant. Harvest index, 1000-seed weight and spring vigour showed significant positive correlations with seed yield, but days to flower correlated negatively with seed yield. Spring vigour, plant height and number of leaflets per leaf correlated positively, while harvest index, seeds per pod and seeds per plant correlated negatively with straw yield. Correlations between seed and straw yield were both positive and significant.     

Untersuchungen zur Leitbündelstruktur der Ackerbohne (Vicia faba L.)

Investigations on the vessel structures of broad beans ( Vicia faba L.)
The number of vessels was observed in the fruit bearing axes of some varieties from Vicia faba Minor, Equina and Major during flowering. These investigations were also made on some F₂- progenies of crosses from minor × equina and Paucijuga × Eufaba and on some topflower plants.
The varieties of Minor and Equina had about 12 vessels on the base of the axis, these diminished to the top of the axis 3 or 4 vessels just before the last flower. The varieties of Major had 12 vessels on the base of the axis too, but these diminished faster because of the smaller number of flowers on the axis. In Paucijuga the number of vessels on the base of the axis was only 3 to 4. Plants of Paucijuga had only 2 or 3 flowers per axis.
Progenies from crosses between Minor × Equina had more vessels on the base of the axis, probably due to a heterotical inheritance. In progenies from crosses between Paucijuga × Eufaba an intermediate inheritance was found in the number of flowers per axis and in the number of vessels.
Due to the investigations on a comprehensive material it is probable that the described vessel structure exists in most broad beans. This structure is complex arranged and modifyable. With this organization it is quite unprobable that the vessel structure will be a yield reducing factor.     

Heterosis and hybrid performance in topless faba beans (Vicia faba L.)

Parental lines, F₁ and F₂ hybrids from a 7×7-diallel of topless faba beans and eight standard cultivars were grown in single-rows for two years at four sowing dates on a highly fertile loam soil near Göttingen. In grain yield, F₁ hybrids showed 21 to 54% advantage over the higher yielding parent. Compared with the midparental value an average heterosis of 50% was observed for grain yield. Corresponding heterosis mean values ranged from 3 to 37% for yield components and up to 11% for phenological traits. The grain yield of the highest yielding topless F₁ hybrid was equal to that of Alfred, the highest yielding indeterminate standard cultivar. High grain yield in the topless hybrids was closely correlated with high biomass yield, late ripening and tall plants generally having a high number of podded nodes and pods on the main stem. Due to their agronomic advantages, i.e., lower plant length, reduced lodging sensitivity and earlier ripening, efforts at breeding topless hybrids seemed to be worth-while in faba beans. However, their yielding ability must be improved further before they can compete with normal, semi-dwarf and stiff-strawed cultivars.     

Rate and inheritance of cross-fertilization in faba bean (Vicia faba L.)

Summary To assess the feasibility for synthetic varieties of Vicia faba L., 108 faba bean genotypes were screened for cross-fertilization rate in five field experiments carried out in 1989 and 1990 at Wageningen.Significant genotypic differences were observed for outcrossing rate, which ranged from 1 to 55%. These percentages, however, are thought to be not high enough for a commercially feasible production of synthetic varieties.The inheritance of cross-fertilization rate, determined by testing the F₄ generation of a cross between two inbreds, both with high outcrossing rates, appeared to be of a polygenic nature, as was indicated by the wide variation in, and the continous distribution of, the cross-fertilization rates. Among the F₄ lines tested some had a significantly higher cross-fertilization rate than the parents. However, this difference was not found when these lines were retested, indicating that possibilities for successful selection for higher outcrossing rates might be limited.     

Inheritance of seedling colour in faba bean (Vicia faba L.)

Summary The inheritance of purple seedling colour was studied, in relation to the genetic control of flower colour. It was found that purple seedling colour is likely to be controlled by a single gene and that the trait is dominant over green seedling colour. White flowering prohibited the expression of the purple seedling colour, and is therefore thought to be epistatic.This character can be used to estimate rate of outcrossing in breeding programmes, as well as contribute to our knowledge of the biosynthesis of plant pigments and secondary metabolites such as tannins.     

Susceptibility of Faba Bean (Vicia faba L.) to Heat Stress During Floral Development and Anthesis

Experiments were conducted over 2 years to quantify the response of faba bean (Vicia faba L.) to heat stress. Potted winter faba bean plants (cv. Wizard) were exposed to temperature treatments (18/10; 22/14; 26/18; 30/22; 34/26 °C day/night) for 5 days during floral development and anthesis. Developmental stages of all flowers were scored prior to stress, plants were grown in exclusion from insect pollinators to prevent pollen movement between flowers, and yield was harvested at an individual pod scale, enabling effects of heat stress to be investigated at a high resolution. Susceptibility to stress differed between floral stages; flowers were most affected during initial green‐bud stages. Yield and pollen germination of flowers present before stress showed threshold relationships to stress, with lethal temperatures (t₅₀) ?28 °C and ~32 °C, while whole plant yield showed a linear negative relationship to stress with high plasticity in yield allocation, such that yield lost at lower nodes was partially compensated at higher nodal positions. Faba bean has many beneficial attributes for sustainable modern cropping systems but these results suggest that yield will be limited by projected climate change, necessitating the development of heat tolerant cultivars, or improved resilience by other mechanisms such as earlier flowering times.     

Differential Drought Responses of Faba Bean (Vicia faba L.) Inbred Lines

Drought responses of 19 inbred faba bean lines of different origin were studied in the field under rain shelters with and without irrigation. Inbred lines differed significantly in response to drought (P < 0.01): those with a lower drought sensitivity index (SI) (more resistant) originated from the drought-prone regions characterized by smaller plant size (r = 0.93), and more pods and seeds per plant (r ≥ 0.90) regardless of seed size, while lines with higher SI (more sensitive) were those which mainly exhibited higher yield under favourable conditions accompanied by a greater biomass. In a greenhouse experiment under mild drought (−0.15 MPa soil water potential), comparisons between relatively drought-sensitive (Adriewaalse) and drought-resistant (L7) inbred lines showed that Adriewaalse used 38 % more water than L7 and also produced 40 % more biomass. There was a stress-induced decrease in osmotic potential (ψ_s) in both lines (by 0.72 and 0.50 MPa for Adriewaalse and L7, respectively) accompanied by decreased turgor in Adriewaalse and increased turgor in L7. The difference in drought-induced solute accumulation between lines was diminished when solute accumulation due to water loss and growth inhibition was considered, which indicates that solute accumulation was the result of a concentration effect. Similarly, lower SI in the field was not the result of osmotic adjustment, as the relationship between SI and drought-induced decrease in ψ_s was negative. The water use efficiency of both inbred lines increased markedly with increasing water deficit, though there was no difference between the lines. It was concluded that differences in drought resistance between these inbred faba bean lines were manifested through plant size-induced water demand (avoidance) but were not associated with osmotic adjustment (tolerance).     

Autofertility and Bee Visitation in Winter and Spring Genotypes of Faba Beans (Vicia faba L.)

Differences in the expression of autofertility and in the evidence of attractiveness to bees were investigated in both autumn-sown and spring-sown faba beans. All six winter stocks and one spring stock expressed very little autofertility, with averages of only 10% of flowers and 7% of ovules fertilized when undisturbed. Three other spring stocks, including a closed-flower population, were moderately autofertile, with 22% of flowers and 17% of ovules fertilized when undisturbed. The remaining two spring stocks, both English cultivars, expressed good autofertility, with 50% of undisturbed flowers and 44% of ovules fertilized. Current levels of autofertility in the winter and closed-flower stocks were inadequate to allow the development of a desirable distribution of pods without substantial bee visitation. If levels of autofertility could be raised simply by selection within populations, then they should have been much higher in these stocks. Therefore, autofertile parents will probably have to be included in programmes for breeding cultivars with improved levels of auto fertility. The closed-flower population received significantly less bee visitation than the other stocks in the spring trial. No variation in attractiveness to bees was found among the open-flowered spring stocks, nor among the winter stocks.     

Inheritance and linkage of a gene for testa-imposed seed dormancy in faba bean (Vicia faba L.)

Seed dormancy in the grain legumes may interfere with germination in some situations, yet is not well described. Dormancy in faba bean (Vicia faba L.) was investigated to determine the mode of inheritance and whether the gene or genes controlling this trait are linked to other genes. Seeds produced by 235 recombinant inbred lines at the F₆ generation were used for this study. The parents were the cultivar ‘Optica’ and 172, an Afghanistan landrace which possesses extended seed dormancy. Germination was scored on a seed sample from each recombinant inbred line. Segregation patterns indicated that the trait is monogenic. This gene, named doz, is linked to a gene controlling anthocyanin and proanthocyanidin synthesis, sp-b, with the genetic distance estimated to be about 25 cM. No associations were detected between seed dormancy and pod dehiscence, seed lustre or mean seed weight. The implications of the persistence of a gene for seed dormancy in the gene pool of V. faba for the introgression of traits from landraces and cultivars possessing dormancy and for the origins of domesticated V. faba are discussed.     

Stomatal and Non-stomatal Effects of Salinity on Photosynthesis in Faba Beans (Vicia faba L.)

The effect of salinity (40 and 80 meq/1 NaCl) on stomatal conductance, chlorophyll content, ultrastructural damage and photosynthetic performance of six cultivars of faba beans ( Vicia faba L.) from different agroclimatic regions were investigated. Low levels of salinity (40 meq/1 NaCl) increased chlorophyll content in some cultivars but did not lead to simultaneous increase in photosynthesis (P). Increased salinity levels (80 meq/1 NaCl) decreased chlorophyll content and stomatal conductance. Ultrastructural damage was observed in sensitive cultivars even at low salinity levels. Based on the parameters investigated, there was no concrete evidence to suggest that the physiological processes of cultivars from arid and semi-arid regions are less affected under saline conditions as compared to cultivars from temperate regions. The results suggested increased salinity affects P not only due to its effect on stomatal closure but also due to other non-stomatal effects like ultrastructural damage and decrease in chlorophyll content below a threshold level.     

Narbon Vetch (Vicia narbonensis L.): A Potential Feed Legume Crop for Dry Areas in West Asia

Provision of feed supplies for the rapidly growing livestock population is essential in West Asia. Shortages can be alleviated by growing forage crops in the existing fallow lands.
Narbon vetch (Vicia narbonensis L.) is a leguminous species with high yield potential, drought tolerance and cold resistance. It could be used for grain and straw production as source for animal feed in dry areas. It is good source of protein with seeds contain 28 % protein yielding 364 kg per hectare protein, whilst straw contains 9 % protein and yields a similar amounts of digestible protein per hectare.
Nine promising lines of Narbon vetch developed at ICARDA were tested at two sites over four years under rainfed conditions. Since climatic conditions were considered to be of considerable importance, each site in each year was treated as a separate environment to give eight environments with annual rainfall varied from 195 to 504 mm.
Narbon vetch possessed high seedling vigour with rapid winter growth and negligible cold damage. Grain yield varied form 0.47 to 1.90 t/ha, with a harvest index varying from 30 to 40 %. The data indicated that below 300 mm rainfall the grain yield varied from 0.47 t/ha when rain fall was 195 mm to 1.4 t/ha when rainfall was 245 mm. Most of the lines had wide adaptation to dry areas in terms of both grain yield and stability. Climate, except early spring rains had little effect on biological and grain yields.     

Genetics of colour traits in common vetch (Vicia sativa L.)

Five parents of common vetch (Vicia sativa L.) having orange/beige cotyledon colour, brown/white testa colour, purple/green seedling colour and purple/white flower colour were crossed as a full diallele set. The inheritance patterns of cotyledon, testa or seed coat colour, flower and seedling colour, were studied by analyzing their F₁, F₂, BC₁ and BC₂ generations. The segregation pattern in F₂, BC₁ and BC₂, showed that cotyledon colour was governed by a single gene with incomplete dominance and it is proposed that cotyledon colour is controlled by two allelic genes, which have been designated Ct₁ and Ct₂. Testa colour was governed by a single gene with the brown allele dominant and the recessive allele white. This gene has been given the symbol H. Two complementary genes governed both flower and seedling colours. These flower and seedling colour genes are pleiotropic and the two genes have been given the symbols S and F.     

Study on the Inheritance and Relationship of Some Morphological and Fertility Characters in Faba Bean (Vicia faba L.)

Inheritance of several morphological and fertility characters was studied in F2 generation of two sets of diallel cross, using Griffing's analysis of variance. A paramount importance of general combining ability (GCA) over specific combining ability was measured for most studied characteristics. Correlations among GCA values for seed yield, morphological and fertility characters do not give a clear definition of the plant ideotype. “Terminal inflorescence” character appeared to reduce the seed per ovule ratio. Higher additive component was found for the ovule per pod than for seed per pod characters.     

Variation and covariation in Vicia faba L. populations of Mediterranean origins

Summary Variation and covariation in 15 Vicia faba L. ssp. major populations from Italy. Greece and Egypt were analyzed. Ten quantitative morphobiological characters of agronomical and nutritional interest were observed. Differences among countries of origin were highly significant for all characters except for lowest podded node. Phenotypic distances among populations, both within and among origins, estimated on canonical variates evidenced that the Egyptian populations from a distinct group and that a relevant degree of similarity exists among the Greek and the Italian meterial. The covariation structure within populations, which was studied by means of factor analysis, was comparatively simpler in the Egyptian material than in that form the other two Mediterranean countries. The differences evidenced can be attributed to different gene associations between characters and suggest the possibility of obtaining, through recombination, genotypes agronomically more favorable.Research work supported by C.N.R., Italy, special grant. Sub-Project 1, Paper No. 299.     

Variation in the crude protein content of field beans (Vicia faba L.) in relation to the possible improvement of the protein content of the crop

Summary A survey of the protein content of various field bean varieties indicates a range of variation extending over sixteen units of crude protein from 22–38%. Analysis of single plants from within three WPBS varieties Dylan. Danas and Dacre indicates that a similar range exists within commercial varieties. Examination of the progenies of high and low protein single plant selections together with a preliminary estimation of heritability suggest that protein content is highly heritable. No significant correlations were found between protein content and seed yield.