Performance of Common Bean (Phaseolus vulgaris L.) Landraces from Spain in the Atlantic and Mediterranean Environments

Ninety-five common bean (Phaseolus vulgaris L.) landraces from Spain were evaluated in three different environments in northern Spain for their agronomic performance and seed quality. Significant differences among landraces were found for 14 quantitative traits related to phenology, yield and its components, and seed quality traits. Environmental effects were significant for all traits evaluated except for seeds pod^?1, seed width/thickness, seed weight, and seed water absorption. Landrace by environment interactions were significant for all traits except for seeds pod^?1 and seed water absorption. Selection of new breeding lines for agronomic performance and seed quality within landraces should be reliable because many of them are mixture of lines. Some heirloom varieties belonging to the types faba, caparrón,riñón,ganxet and tolosana had the best performances regarding to seed quality and yield. Principal component analysis revealed differences among environments affecting the performance of the bean landraces. Variation in the landraces seems to be organized in a different way in each one of the test environments, therefore, low plasticity and specific adaptation of Spanish bean landraces to different environments is derived from this study. Some landraces, especially those large and white seeded should be an useful resource for sustainable farming systems in different biogeographical areas and a worthy germplasm for the genetic improvement of agronomic value and seed quality.     

Genetic relationships among cultivated and wild <Emphasis Type="Italic">Vigna angularis</Emphasis> (Willd.) Ohwi et Ohashi and relatives from Korea based on AFLP markers

Genetic variation and relationships among members of the azuki bean complex (Vigna angularis) including wild (V. angularis var. nipponensis), weedy, and cultivated types (V. angularis var. angularis), V. nakashimae, and rice bean (V. umbellata) from Korea were examined using the Amplified fragment length polymorphism (AFLP) method. AFLP analysis of 50 accessions revealed 333 (72.1%) polymorphic fragments out of 462 fragments amplified using seven primer combinations. The number of polymorphic fragments within each species was 70 in the azuki bean complex and 41 in V. nakashimae, but there was no polymorphism in rice bean. The number of shared fragments among species ranges from 142 between the azuki bean complex and V. nakashimae to 166 between the azuki bean complex and rice bean. Within the azuki bean complex, the range of shared bands was from 231 between cultivated and weedy types to 238 between cultivated and wild types. A dendrogram generated from Jaccard’s similarity matrix was divided into three groups, which correspond to V. nakashimae, azuki bean complex, and rice bean. The relationship between azuki bean and rice bean is closer than between azuki bean and V. nakashimae. Phenetic distances averaged 0.502 between the azuki bean complex and V. nakashimae and 0.467 between the azuki bean complex and rice bean. Within the azuki bean complex, the weedy type was more closely related to wild than cultivated types. But UPGMA dendrogram of the azuki bean complex reveals that each type is not clearly isolated. These results will help to understand genetic diversity and evolutionary dynamics of Vigna in Korea.     

Genetic erosion and in situ conservation of Lima bean (Phaseolus lunatus L.) landraces in its Mesoamerican diversity center

Lima bean (Phaseolus lunatus L.) is an important crop in traditional Mayan agriculture of the Yucatan Peninsula, Mexico, its Mesoamerican center of diversity. Genetic erosion in this species is currently a threat in this region out of 3 of 21 landraces dominate 71.24% of the cultivated area, and 12 are rare landraces grown only in 6.29%. Using 90 ISSR loci, we estimated the diversity and genetic relationships for 21 landraces to analyzing their risk of genetic erosion, and generate data for their in situ conservation. Total genetic diversity was high (h = 0.29), however it was lower than wild gene pool reported (h = 0.69). The abundant landraces had genetic diversity values lower (h = 0.13, I = 0.17) than the common (h = 0.26, I = 0.33) and rare landraces (h = 0.24, I = 0.27). However, the rare landraces are in a higher risk of genetic erosion due to local extinction. The cluster analysis showed no groups corresponding to morpho-phenological characteristics, geographic origin or traditional classification, which resulted from high inter-landraces gene flow levels. The molecular data confirmed that the domesticated Lima bean pool of the Yucatan Peninsula has a high risk of genetic erosion. If current tendencies in landrace cultivation continue, many will no longer be planted within two to three generations, with a consequent loss of their alleles. Programs urgently need to be established for in situ conservation of Lima bean landraces in this region.     

Extensive introgression of Middle American germplasm into Chilean common bean cultivars

Summary The genetic diversity of 95. representative Chilean common bean (Phaseolus vulgaris L.) landraces was analyzed using phaseolin seed protein and eight isozyme systems as genetic markers. Four types of phaseolin were found, “C”, “T”, “S” and “H”, in decreasing order of frequency. Each type had a different distribution between the Northern and Southern regions of the country. Nei’s genetic distance based on isozyme diversity indicated that a high percentage of the total variation found in this sample occurred between landraces and only a small percentage of the variation was detected within populations. Cluster analysis based on Nei’s genetic distance and a principal component analysis of isozyme frequencies did not detect a clear association between the geographic distribution of the landraces and their isozyme constitution. However, Nei’s genetic distance analysis clustered the bean landraces into two major groups which had a specific isozyme pattern, seed color, and seed size. The genetic analysis also detected a rare polymorphism for theMdh-2 locus, a null allele at theDiap-2 locus, and polymorphism for theAco-2 locus. The principal component analysis of isozyme frequencies showed that only 30% of the genotypes analyzed were similar to the Andean check and 5% of the samples were similar to Middle American check. This finding suggests a high frequency of hybridization between the Middle America and Andean gene pools in cultivated common bean from Chile.     

Phenotypic diversity of durum wheat (<Emphasis Type="Italic">Triticum durum</Emphasis> Desf.) from Jordan

Durum wheat landrace genotypes are disappearing from the main wheat areas in Jordan, because of spreading of new uniform cultivars and the serious reduction in wheat cultivation. This study was conducted to evaluate genetic diversity in durum wheat landraces from Jordan and to identify desirable agronomic traits. Landraces were collected from two target areas: Ajloun and Karak. The collected material was grown under rainfed conditions using an augmented design with five blocks and four repeated check cultivars. Data were collected for 14 morphological and agronomic traits. Phenotypic diversity index (H′) was estimated, and the relationships among accessions were measured using cluster analysis and dendrogram similarity matrix. The results revealed the presence of a wide range of variability among landraces., which possess high levels of variability for biological yield, fertile tillers, number of seeds per spike, seed weight per spike and weight of 1000 seeds. These landraces must be considered as a reservoir of genes that plant breeders need in their wheat improvement programs and should be conserved both ex situ and in situ.     

Primitive weedy forms of guar,adak guar: possible missing link in the domestication of guar [<Emphasis Type="Italic">Cyamopsis tetragonoloba</Emphasis> (L.) Taub.]

Crop domestication has lead to the selection of a wide range of traits that distinguish domesticated crops from their wild ancestors. Over the past four decades, concerted efforts by archaeologists and geneticists have provided novel insights into the domestication of crops. However, minor crops are rarely a subject for intensive domestication studies and very less is known on the domestication of guar [Cyamopsis tetragonoloba (L.) Taub.] except the trans-domestication hypothesis. The hypothesis proposes that the domestication of guar took place in recent times in the dry areas of the northwestern region of Indo-Pakistan subcontinent and the African wild species, C. senegalensis Guill. et Perr., as its ancestor. However, the process by which the wild species was domesticated is not fully understood. The present paper describes the exploration, collection and in situ characterization of the primitive weedy forms of guar that could be the missing link between the wild and cultivated species. Adak guar is found to grow along with cultivated guar as a weed and is characterized by several primitive characters, prominent among which are spreading habit, small inedible pods which shatter at maturity, hard seed coat and seed dormancy. A total of 66 germplasm collections of these primitive weedy forms of guar have been made from naturally occurring populations in the arid regions of northwestern India. Systematic studies involving these primitive weedy forms can help in understanding the domestication bottlenecks and in utilizing the genetic variation lost during the process of domestication for the improvement of cultivated guar.     

Genetic diversity in the Lima bean (Phaseolus lunatus L.) as revealed by chloroplast DNA (cpDNA) variations

Genetic diversity in the Lima bean (P. lunatus L.) was assessed bymeans of two chloroplast DNA probes. Based on data obtained from 152accessions including wild forms and landraces, the two separateMesoamerican and Andean groups were confirmed and a transition poolof genetic diversity was observed in the two botanical formsconsistent with their distribution range. Three primary centres ofgenetic diversity and one secondary diversification spot are proposedfor the wild Lima bean whereas only two domestication sites areunderlined for the landraces. The importance of human intervention inwidening the distribution range and the genetic diversity inlandraces is discussed.     

Collection of Lupinus angustifolius L. Germplasm and Characterisation of Morphological and Molecular Diversity

Lupinus angustifolius L. is a Mediterranean species, domesticated in the 20th century, representing an important grain legume crop in Australia and other countries. This work is focused on the collection of wild germplasm and on the characterisation of morphological and molecular diversity of germplasm accessions. It reports the collection of 81 wild L. angustifolius accessions from the South and Centre of Portugal, available at the ‘Instituto Superior de Agronomia Gene Bank’, with subsequent morphological and molecular characterisation of a selection of these and other accessions. A multivariate analysis of morphological traits on 88 L. angustifolius accessions (including 59 wild Portuguese accessions, 15 cultivars and 14 breeding lines) showed a cline of variation on wild germplasm, with plants from Southern Portugal characterised by earlier flowering, higher vegetative development and larger seeds. AFLP and ISSR molecular markers grouped modern cultivars as sub-clusters within the wider diversity of wild germplasm, revealing the narrow pool of genetic diversity on which domesticated accessions are based. The importance of preserving, characterising and using wild genetic resources for L. angustifolius crop improvement is outlined by the results obtained.     

Nutritional composition and cooking characteristics of tepary bean (<Emphasis Type="Italic">Phaseolus acutifolius</Emphasis> Gray) in comparison with common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.)

Tepary bean is a highly abiotic stress tolerant orphan crop for which there has been limited research on its nutritional value and cooking characteristics. These are key aspects when considering the potential for broader adoption of tepary bean. Therefore, the goal of this study was to evaluate a large set of seed composition and cooking traits related to human nutrition using both landraces and breeding lines of domesticated tepary bean from replicated field trials and to compare the traits in tepary with those in common bean. Tepary bean showed reduced fat and ash concentration and higher sucrose concentration as compared to common bean. Of the twelve amino acids evaluated, only proline in one of the two trials was statistically different between the two species. There were statistically significant differences between tepary and common bean for the concentration of some elements in this study; however, the elemental concentrations fell within the range of those found for common bean in previous studies. The majority of tepary bean lines showed consistently short cooking times and a high percentage of seeds showed measurable water uptake, while some showed a hardshell trait (low water uptake) and longer cooking times. Principal component analysis on a subset of traits showed a distinct group of common beans and two tepary bean groups that were divided on the basis of several agronomic, cooking, and elemental composition traits. Tepary bean, as with other pulses, is a highly nutritious crop with the range of composition and cooking characteristics similar to those of common bean. The variability for seed composition and cooking traits found within tepary bean can be exploited for its improvement.     

Lablab purpureus (L.) Sweet – diversity, potential use and determination of a core collection of this multi-purpose tropical legume

Two germplasm collections of Lablab purpureus L. Sweet totalling 249 accessions were grown in the field in Australia and Ethiopia and characterised using a common set of morphological and agronomic (M-A) attributes. Data from each site were analysed separately using multi-variate analysis and a classification constructed for each collection. There was considerable diversity within both collections, especially that maintained in Ethiopia. Time to flowering, seed weight, and plant height were the most important attributes in determining group allocation in both classifications. Both collections had a high proportion of L. purpureus subsp. purpureus, especially accessions similar to the Australian cultivars Highworth and Rongai. They also had good representation of the less common L. purpureus subsp. uncinatus Verdc. less common landraces and wild collections from either Africa or India. When combined, the two classifications provided an overview of diversity and highlighted the similarities and dissimilarities between the two collections. The vast range in plant types supported the view that lablab has the capacity to be a multi-purpose legume for both commercial and smallholder agriculture. Some important and less common germplasm identified were Ethiopian domesticated subsp. uncinatus, Ethiopian subsp. purpureus landraces collected from regional markets, semi-domesticated and wild accessions from southern Africa, and wild accessions from India. Using this overview, a core collection of germplasm was selected, which provides researchers with a sound basis for future plant breeding and agronomic studies with this important tropical legume.     

Evidence for two gene pools of the Lima bean,Phaseolus lunatus L., in the Americas

Summary The lima bean,Phaseolus lunatus L., is a bean species with a broad distribution in the Americas that rivals that of common bean (P. vulgaris). In order to better understand the organization of genetic diversity and the pattern of domestication in lima bean, a review was conducted of the available information on the geographic distribution of wild and cultivated forms of this species. In addition, one-dimensional SDS polyacrylamide gel electrophoresis of seed proteins was also conducted on a sample of 84 wild, 6 weedy, and 426 cultivated forms. Results show that wild forms can be divided into two groups, one with smaller seeds and a very extensive distribution that includes Mexico, Central America, and the eastern slope of the Andes, and the other with a more circumscribed distribution on the western slope of the Andes in Ecuador and northern Peru. Electrophoretic analyses of seed proteins confirmed this subdivision and, additionally, showed that the large-seeded cultivars had been domesticated from the large-seeded wild lima beans in western South America. For the small-seeded lima bean cultivars, it was not possible to determine a domestication center as the most abundant protein pattern in the cultivars also had a widespread distribution in the small-seeded wild progenitor. Electrophoretic analyses showed, however, that domestication led to a reduction of genetic diversity in the small-seeded, Mesoamerican group, but not in the large-seeded group. The latter may be due to insufficient sampling of the larger-seeded, wild germplasm.     

Characterization of Some Italian Common Bean (<Emphasis Type="Italic">Phaseolus Vulgaris</Emphasis> L.) Landraces by RAPD,Semi-random and ISSR Molecular Markers

Randomly amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and a semi-random PCR system were used to analyze the genetic diversity of 16 Italian common bean landraces and their relationship to four commercial cultivars. Of the primers tested, 8 ISSR, 6 RAPD and 7 semi-random primers produced polymorphic and reproducible DNA fragments. A higher proportion of polymorphic bands were observed using ISSR (85%) and semi-random (90%) primers than RAPD (69%) method. The combination of any two semi-random markers allowed the identification of all 20 bean genotypes. In contrast ISSR (except for primer (CAC)₃GC) and RAPD markers appeared to be less informative as more than two markers were necessary to achieve the same diagnostic level. Moreover, 7 ISSR, 2 RAPD and 8 semi-random exclusive bands were identified as putative population-specific markers. Semi-random and ISSR derived dendrograms showed similar tendencies in terms of genetic relatedness, whereas clustering of genotypes within groups was not similar when compared with the RAPD technique. Despite the different ability to resolve genetic variation among the investigated landraces, two major clusters with less than 60% (ISSR) and 40% (RAPD and semi-random) genetic similarity were formed with all three marker systems. The two groups were correlated with the phaseolin patterns and seed size of the landraces. The analysis showed that the cultivar ȁ8Lingua di Fuocoȁ9 and most of the landraces (13 out of 16) collected in Italy belong to the Andean gene pool, whereas only the three populations from Pratomagno belong to the Middle American gene pool.     

Genetic differentiation and diversity of phenotypic characters in Chinese wild soybean (<Emphasis Type="Italic">Glycine soja</Emphasis> Sieb. et Zucc.) revealed by nuclear SSR markers and the implication for intraspecies phylogenic relationship of characters

Genetic diversity is reduced from wild soybean to cultivars and from landraces to modern varieties. However, intraspecies genetic diversity loss between characters or phenotypes also existed in wild soybean. We revealed the phylogenic relationship of character types in Chinese wild soybean using 42 SSR markers. We conjectured that white flower, no-seed bloom, grey pubescence, and four seed coat colours were evolutionarily acquired phenotypes. There were a small decrease (∆H = 0.1–6.46%) of gene diversity and a moderate reduction (∆Na = 10.81–53.54%) of number of alleles but a violent loss (80.74–98.59%) of unique alleles in the acquired phenotypes. Our results seemed to suggest that ovoid and elliptic leaves were differentiated at the earliest and subsequently lanceolate leaf appeared before the domestication of soybeans within wild soybean, and that G. gracilis type was another earliest type, maybe emerged since the appearance of soybeans or it was concomitant with the domestication of soybean.     

AFLP analysis of genetic diversity in five accessions of Polish runner bean (<Emphasis Type="Italic">Phaseolus coccineus</Emphasis> L.)

Runner bean (Phaseolus coccineus L.) is traditionally cultivated in Poland for dry seeds. The national collection of runner bean maintained in the National Center for Plant Genetic Resources gathers 152 accessions, which are mainly landraces originated in Poland (68%), Ukraine (17%) and Slovakia (10%). The collection contains valuable genetic resources for bean breeders and research. The aim of this study was to describe the level and structure of genetic diversity of three landraces and two commercial cultivars of runner bean from the national collection in order to assess their genetic potential for breeding. Amplified Fragment Length Polymorphism analysis included five combinations of selective primers. Analysis of seven genetic diversity parameters reveled fair amount of genetic variation both in landraces and cultivars. High genetic diversity of commercial cultivars relative those of landraces suggests that the breeding process leading to their release was rather moderate and most likely included domestic gene pool of runner bean. Low gene diversity and low Nei’s genetic distance values as well as intergradations among accessions in the PCoA may indicate reduced variability P. coccineus grown in Poland as a result of its migration pathways.     

Wholesale replacement of lima bean (<Emphasis Type="Italic">Phaseolus lunatus</Emphasis> L.) landraces over the last 30 years in northeastern Campeche,Mexico

Genetic erosion has been evaluated at the landrace level in the past, principally because the loss of landraces is believed to generate erosion at the allelic level; however, few studies had tested this hypothesis in the crop’s centers of diversity and domestication. Using microsatellite markers, we analyzed for genetic erosion in lima bean (Phaseolus lunatus) landraces over time in samples collected in 1979 and in 2007 in northeast Campeche, in the Yucatan peninsula, Mexico, an important diversity center and part of the putative domestication area for this crop. We found that the lima bean genetic pool from 1979 had a higher genetic diversity than the one for the 2007 pool (Nei’s diversity, H = 0.18 and 0.05, respectively). Although this result could not to be explained using a bottleneck analysis, a cluster analysis showed that the alleles present in 1979 were not the same as those found in 2007, indicating an allelic displacement in the genetic pool of the lima bean landraces in the last 30 years. This displacement could be due to the introduction of improved varieties or landraces, resulting in a displacement of local varieties or to changes in the Mayan criteria for selection of germplasm or both. This study showed that the loss of landraces can generate both quantitative and qualitative changes in the genetic pool of the domesticated species. Such changes are very important to consider when planning ex situ and in situ programs to conserve crop diversity in their domestication areas.     

Genetic Structure of Wild and Domesticated Populations of Capsicum annuum (Solanaceae) from Northwestern Mexico Analyzed by RAPDs

Levels of genetic variation and genetic structure of 15 wild populations and three domesticated populations of Capsicum annuum were studied by RAPD markers. A total of 166 bands (all of them polymorphic) and 126 bands (125 of them polymorphic) were amplified in wild and domesticated populations, respectively. Mean percentage of polymorphism was 34.2% in wild populations and 34.7% in domesticated populations. Mean and total genetic diversity were 0.069 and 0.165 for wild populations and 0.081 and 0.131 for domesticated populations. Parameters of genetic diversity estimated from 54 bands with frequencies ≥1 − (3/n) (n = sample size) showed that 56.7% of the total variation was within and 43.3% among wild populations, whereas 67.8% of the variation was within and 32.2% among domesticated populations. AMOVA indicated that total genetic diversity was equally distributed within (48.9 and 50.0%) and among (50.0 and 51.1%) populations in both wild and domesticated samples. Wild and domesticated populations were clearly resolved in a UPGMA dendrogram constructed from Jaccard’s distances (average GD = 0.197), as well as by AMOVA (17.2% of variance among populations types, p = 0.001) and by multidimensional scaling analysis. Such differentiation can be associated with domestication as well as different origin of gene pools of the wild (Northwestern Mexico) and cultivated (more probably Central Mexico) samples analyzed. The considerable genetic distances among cultivars (average GD = 0.254) as well as the high number of diagnostic bands per cultivar (33 out of 126 bands), suggest that genetic changes associated with domestication could have resulted from artificial selection intervening in different directions, but the inclusion of more domesticated samples might clarify the nature of distinctions detected here.     

AFLP analysis of genetic diversity in leafy kale (<Emphasis Type="Italic">Brassica oleracea</Emphasis> L. convar. <Emphasis Type="Italic">acephala</Emphasis> (DC.) Alef.) landraces,cultivars and wild populations in Europe

AFLP markers were used to characterize diversity and asses the genetic structure among 17 accessions of kale landraces, cultivars and wild populations from Europe. The range of average gene diversity in accessions was 0.11–0.27. Several landraces showed higher levels of diversity than the wild populations and one cultivar had the lowest diversity measures. The landraces that were most genetically diverse were from areas where kales are known to be extensively grown, suggesting in situ conservation in these areas as a supplement to storage of seeds in gene banks. An analysis of molecular variance (AMOVA) showed that 62% of the total variation was found within accessions. For most accessions, genetic distance was not related to geographic distance. Similarities among accessions were probably not caused by recent gene flow since they were widely separated geographically; more likely the relationship among them is due to seed dispersal through human interactions. Our results indicate that a kale population found in a natural habitat in Denmark was probably not truly wild but most likely an escape from a cultivated Danish kale that had subsequently become naturalized.     

Cultivation of lotus (<Emphasis Type="Italic">Nelumbo nucifera</Emphasis> Gaertn. ssp. <Emphasis Type="Italic">nucifera</Emphasis>) and its utilization in China

Lotus (Nelumbo nucifera Gaertn. ssp. nucifera), one of 12 aquatic species used as vegetable, has been cultivated for more than 2,000 years, and now has been widely cultivated in almost all provinces in China. The largest area under cultivation of lotus is located in the regions surrounding mid-down Yangtse River, including Hubei, Jiangsu, Zhejiang, Anhui, Jiangxi and Hunan provinces. According to different purposes or morphological differences, the Chinese lotus (N. nucifera ssp. nucifera) is usually classified into three types: rhizome lotus, seed lotus and flower lotus. Rhizome lotus is mainly cultivated in Hubei, Jiangsu, Anhui and Zhejiang provinces; Seed lotus in Jiangxi, Fujian and Hunan, and flower lotus in Wuhan, Hubei province, and Beijing. Up to the year 2002, a total of 572 lotus accessions (including landraces, cultivars and breeding lines) were conserved in National Garden of Aquatic Vegetable, Wuhan, Hubei province, including those collections from 153 counties in 18 provinces, and lines bred by breeders. Out of these accessions, 310 were rhizome lotus which contains 201 landraces and 109 breeding lines; 229 were flower lotus including 172 cultivars and 57 breeding lines; and the rest 33 were seed lotus with 18 cultivars.     

Italian common bean landraces: diversity and population structure

Phaseolus vulgaris L. is an important species that originated in Mesoamerica. A Mesoamerican and an Andean gene pool are usually distinguished in the domesticated forms. Many bean landraces are still cultivated in Italy and the Department of Applied Biology maintains an ex situ collection of 146 landraces. Although protection schemes are being developed in Italy, most landraces are extinct or at risk of extinction. To facilitate their conservation and use, geographical, morphological, biochemical and molecular (SSR) data were collected and analysed to estimate the diversity and the genetic structure of the collection. Data confirmed that both the Mesoamerican and the Andean gene pools were introduced in Italy and, although a distinction between the two gene pools exists, the Italian landrace diversity is clearly structured in three clusters that are not simply ascribable to the original gene pools. The observed structure appears also to be due to adaptation to the different environmental conditions determined by altitude. This was confirmed by assessing the presence of selective effects for some of the SSR used in this study. Finally, a certain extent of admixture in Italian landrace diversity suggests past (or recurring) hybridisation events among gene pools. The combined use of morphological, biochemical and molecular data clearly distinguished almost all the landraces. The data gathered here can assist landrace in situ protection schemes that are being developed in Italy, be used to register landraces in the European common catalogue of ‘conservation varieties’ for seed commercialisation and contribute to a better use of Italian common bean diversity in breeding for organic and conventional production systems.