Density enhancement of a faba bean genetic linkage map (Vicia faba) based on simple sequence repeats markers

Genetic mapping for faba bean lags far behind other major crops. Density enhancement of the faba bean genetic linkage map was carried out by screening 5,325 genomic SSR primers and 2033 expressed sequence tag (EST)‐SSR primers on the parental cultivars '91825' and 'K1563'. Two hundred and fifteen genomic SSR and 133 EST‐SSR primer pairs that detected polymorphisms in the parents were used to screen 129 F₂ individuals. This study added 337 more SSR markers and extended the previous linkage map by 2928.45 cM to a total of 4516.75 cM. The number of SSR markers in the linkage groups varied from 12 to 136 while the length of each linkage group ranged from 129.35 to 1180.21 cM. The average distance between adjacent loci in the enhanced genetic linkage map was 9.71 cM, which is 2.79 cM shorter than the first linkage map of faba bean. The density‐enhanced genetic map of faba bean will be useful for marker‐assisted selection and breeding in this important legume crop.     

Development of EST-SSR markers and construction of a linkage map in faba bean (Vicia faba)

To develop a high density linkage map in faba bean, a total of 1,363 FBES (Faba bean expressed sequence tag [EST]-derived simple sequence repeat [SSR]) markers were designed based on 5,090 non-redundant ESTs developed in this study. A total of 109 plants of a ‘Nubaria 2’ × ‘Misr 3’ F₂ mapping population were used for map construction. Because the parents were not pure homozygous lines, the 109 F₂ plants were divided into three subpopulations according to the original F₁ plants. Linkage groups (LGs) generated in each subpopulation were integrated by commonly mapped markers. The integrated ‘Nubaria 2’ × ‘Misr 3’ map consisted of six LGs, representing a total length of 684.7 cM, with 552 loci. Of the mapped loci, 47% were generated from multi-loci diagnostic (MLD) markers. Alignment of homologous sequence pairs along each linkage group revealed obvious syntenic relationships between LGs in faba bean and the genomes of two model legumes, Lotus japonicus and Medicago truncatula. In a polymorphic analysis with ten Egyptian faba bean varieties, 78.9% (384/487) of the FBES markers showed polymorphisms. Along with the EST-SSR markers, the dense map developed in this study is expected to accelerate marker assisted breeding in faba bean.     

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.     

Classification of Southeast Asian mints (Mentha spp.) based on simple sequence repeat markers

Mentha is a complex genus encompassing many species as a consequence of their interspecific hybridization and polyploidy. Southeast Asian mints have been poorly distinguished though they are widely used for culinary and medical purposes. In this study, we have analyzed Southeast Asian mints and known varieties as well as a related Lamiaceae species (Nepeta sp.) using simple sequence repeat (SSR) markers and leaf morphology. Two types of mints were clearly distinguished based on their venation pattern and leaf shape index. We developed 12 SSR markers that allowed good amplification in the Mentha and another Lamiaceae species. In the SSR-based phylogram, the Mentha lines could be delimited into groups I–VI. The Southeast Asian mints divided into groups I and II, and the phylogram separated most of the available species, with groups I and II containing the known species M. × cordifolia and M. arvensis, respectively. The separation of the two groups was supported by a population structure analysis. The SSR markers developed in this study enabled the simultaneous classification of mints and will help improve our understanding of the genetic composition of known mint varieties and as yet unclassified Southeast Asian mints.     

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.     

Genetic linkage map construction for white jute (Corchorus capsularis L.) using SRAP,ISSR and RAPD markers

White jute (Corchorus capsularis) and dark jute (Corchorus olitorius) are two important cultivated crops that are used for natural fibre production. Some genetic maps have been developed for dark jute, but the genetic map information for white jute (C. capsularis) is limited. In this study, a linkage map comprising 44 sequence‐related amplified polymorphisms (SRAPs), 57 intersimple sequence repeats (ISSRs) and 18 randomly amplified polymorphic DNA (RAPD) covering 2185.7 cM with a mean density of 18.7 cM per locus was constructed in an F₂ population consisting of 185 individuals derived from a cross between two diverse genotypes of ‘Xinxuan No. 1’ and ‘Qiongyueqing’ in white jute. These markers were evenly distributed in the linkage groups without any clustering. This genetic linkage map construction will facilitate the mapping of agronomic traits and marker‐assisted selection breeding in white jute.     

The identification of faba bean (Vicia faba L.) trisomics by translocation tester set

Summary Five subtelocentric primary trisomics of Vicia faba L. were isolated from crosses between asynaptic mutants and normal plants or translocation tester stocks. The extra chromosome of each trisomic was identified cytologically by critical multivalent association at metaphase I of meiosis.     

Inheritance of seed coat colour in broad bean (Vicia faba L.)

Summary The inheritance of the seed coat colours violet, spotted, brown, green, red, black and beige was investigated in a 10×10 diallel cross between broad bean (Vicia faba L. major) lines. Spotted seed colour was dominant over any uniform seed coat colouring. Brown was dominant over black, green and normal (beige colour). Black and red seed parents behaved as recessive in all F₁ progenies. A 3 (coloured): 1 (normal) segregation ratio was observed in the F₂ of crosses of violet, brown, black, red and spotted seed coat parents to nornal seed coloured parents. Green x beige gave a segregation ratio of 9:7 in F₂. When two parents with different seed coat colour were involved in a cross, the F₂ showed a typical digenic segregation ratio thus demonstrating two unlinked and sometimes epistatic loci.Segregation of a multiallelic series at two loci explains all segregation ratios observed for seed coat colour in broad bean.     

Enzyme polymorphism in faba bean (Vicia faba L. minor) accessions. Genetic interpretation and value for classification

Three isozyme sytems glutamate oxaloacetate transaminase (GOT), superoxide dismutase (SOD), and malic enzyme (ME) have been analysed electrophoretically to study the diversity within and between 33 faba bean (V. faba L. type minor) accessions. For comparison, two cultivars (Vesuvio and Talo) were included in the study. Further objective of this study was to classify populations into genetic similar groups. SOD and GOT showed large variation, while ME presented minor change. Principal components, hierarchical cluster, and canonical discriminant analyses produced five groups with significant differences among them. The alleles with low frequency played a significant role in the discrimination. It was concluded that more detailed investigations regarding genetic aspects of enzyme diversity are needed to support the data here reported. This revised version was published online in July 2006 with corrections to the Cover Date.     

Simple sequence repeat markers for botanical varieties of cultivated peanut (Arachis hypogaea L.)

Cultivated peanut (Arachis hypogaea L.) consists of six botanical varieties. Identification of DNA markers associated with botanical varieties would be useful in plant genotyping, germplasm management, and evolutionary studies. We have developed 130 simple sequence repeat (SSR) markers in peanut, 38 of which were used in this study because of their ability in detecting genetic polymorphism among 24 peanut accessions. Eight SSR markers were found useful to classify botanical varieties. Among them, six SSR markers were specific to botanical varieties fastigiata and vulgaris, one to botanical varieties hypogaea and hirsuta, and one to botanical varieties peruviana, and aequatoriana. Also, three of them derived from peanut expressed sequence tags (ESTs) were associated with putative genes. As botanical varieties have different morphological traits and belong to different subspecies in A. hypogaea, these markers might be associated with genes involved in the expression of morphological traits. The results also suggested that SSRs (also called microsatellites) might play a role in shaping evolution of cultivated peanut. Multiplex PCR of botanical variety-specific markers could be applied to facilitate efficient genotyping of the peanut lines.     

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.     

Progress towards flowering of faba bean (Vicia faba L.) is more than photothermal

Predicting and understanding the progress towards flowering in faba bean are important to achieve the adaptation and high productivity of the crop under varying environmental conditions. Traditional controlled‐environment experiments showed that the rate of progress towards flowering was dependent mainly on photoperiod and temperature. Here, we highlight the need to include measures of solar radiation and water deficit in order to achieve an adequate model for field conditions. The improved model was assessed in two steps: first with a “basic” model across all 20 cultivars and then with an “extended” model that included terms to fit exceptional cultivars. The two new parameters were necessary to achieve an acceptable fit of progress towards flowering and clearly separated two cultivars, “Kontu” and “Witkiem Manita,” that were significantly quicker to flower than the other 18, which fit a single line. As the regression coefficients of the two exceptional cultivars differed only in intercept, not slope, we conclude that flowering responses to day length, temperature, solar radiation and drought stresses were consistent in this set of germplasm and that the two cultivars differed in earliness “per se.” Growth‐chamber experiments added information about differing ceiling temperatures for progress to flowering in four cultivars and different sensitivities to supraoptimal temperatures.     

Pattern analysis and genotypic x environment interactions in faba bean (Vicia faba L.) populations

Summary Twenty-nine populations of faba bean (Vicia faba L. subsp. major, equina and minor) of mediterranean origin were evaluated for the genetic variability of 12 biomorphological characters at four locations in Apulia and Basîli cata regions (Italy) in 1983–84.A pattern analysis appoach, based on classification and ordination procedures is presented for to characterize differences among population in mean performance and response across environments. Informations about G × E interaction were obtained.Research work supported by CNR, Italy. Special grant I.P.R.A. Sub-project 1. Paper N. 1099.     

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.     

Recovery of Faba Bean (Vicia faba L.) Plants as Affected by Glyphosate

Two field experiments were carried out during 1982/83 and 1983/84 seasons at Experimental Farm of National Research Centre at Shalakan, Kalubia Governorate, Egypt, to study the reversal effect of glyphosate induced phytotoxicity on growth and yield and its components of faba bean by the application of growth factors, i.e., growth regulators, amino acids and nutrient elements at different concentrations. A split plot design with four replications was used in both seasons. The obtained results indicated clearly that: Glyphosate at the two higher doses exhibited varying degrees of phytotoxic symptoms and reduced all the faba bean plant characters except the number of branches/plant. GA₃ alone or in a mixture with cytokinin reversed the phytotoxic effect of the glyphosate herbicide on decreasing the plant height. Cytokinin at 4/1000, phenylalanine and tryptophan at both levels, as well as GA₃ at 50 ppm, reversed the phytotoxic effect of the glyphosate herbicide on decreasing the dry weight/plant cytokinin at 4/1000, tryptophan at both concentrations, as well as, phenylalanine at 500 ppm, reversed the phytotoxic effect of the glyphosate herbicide on decreasing the number and dry weight of pods, seed yield per plant and per ha.     

Parentage analysis of tea cultivars in Japan based on simple sequence repeat markers

Tea cultivars have been bred by individual selection of landraces and by crossbreeding, but the validation of the parentage is limited. In this study, we performed parentage analysis of 79 tea cultivars in Japan based on SSR markers to confirm or identify the parent-offspring relationships among them. The effectiveness of nine SSR markers for parentage analysis was validated by comparing them to the existing cleaved amplified polymorphic sequence markers. The former markers were detectable more alleles than the latter. Simulation of parentage analysis of the tea cultivars predicted biparental origins for 12 cultivars (‘Houshun’, ‘Mie ryokuhou no. 1’, ‘Surugawase’, ‘Tenmyo’, ‘Yamanoibuki’, ‘Harumidori’, ‘Koushun’, ‘Minekaori’, ‘Okumusashi’, ‘Saemidori’, ‘Sofu’, and ‘Toyoka’), in the first five of which candidate parents of yet-to-be-defined pedigree were newly identified. Comparisons of a total of 41 SSR genotypes confirmed the newly-identified parentages of ‘Asahi’ for ‘Tenmyo’, ‘Rokurou’ for ‘Houshun’, ‘Surugawase’, and ‘Yamanoibuki’, and ‘Yamatomidori’ for ‘Mie ryokuhou no. 1’. The maternity of seven cultivars out of the 12 was also confirmed with chloroplast DNA sequences. Uniparental origins were confirmed for 25 cultivars. This parentage analysis has improved our knowledge of tea pedigrees and will aid in the development of new cultivars.     

Genetic linkage map of cassava (Manihot esculenta Crantz) based on AFLP and SSR markers

To generate a genetic linkage map of cassava ( Manihot esculenta Crantz), 58 F₁ progenies from a cross between Rayong 90 (female) and Rayong 5 (male) were examined in amplification fragment length polymorphism (AFLP) and simple sequence repeat (SSR) analyses. A total of 469 polymorphic markers consisting of 378 AFLPs generated from 76 primer combinations and 91 SSRs were identified. These markers were analyzed using the joinmap ^® 3.0 package program to construct a genetic linkage map. A total of 33 linkage groups of a common map were constructed from 119 AFLPs and 18 SSRs, spanning 1095 cM with an average of 7.99 cM between markers. The genetic linkage map generated in this study will be useful for genetic studies in cassava particularly for the identification of genetic markers linked to traits of interest, although the complex cassava genome suggests that maybe a long term objective.     

Competition between Canada Thistle [Cirsium arvense (L.) Scop.] and Faba Bean (Vicia faba L.)

This study was conducted to investigate whether density, above-ground biomass and nitrogen (N) concentration of Cirsium arvense (L.) Scop. cause serious reductions in faba bean ( Vicia faba L.) yield. A 2-year field experiment (1991–93) with four Cirsium densities (0, 4, 16, 64 plants m^–2) was carried out. Statistical analysis showed a significant effect of Cirsium density on faba bean yield. Multiple regression analysis showed that the main factors causing faba bean yield losses were the density and above-ground biomass of Cirsium . The results of this study demonstrate that Cirsium competition reduces faba bean yield. The mean faba bean yield losses over the 2 years were 10, 12 and 8% for above-ground biomass, seed and stem, respectively, for a Cirsium density of 16 plants m^–2.