Diversity of common bean (Phaseolus vulgaris L.) germplasm from Portugal

Common bean (Phaseolus vulgarisL.) is a traditional crop in Portugal, where farmers growvarieties selected and maintained by themselves. A collection of 88landraces of common bean was evaluated for 17 quantitative andqualitative traits and the biochemical marker phaseolin to displaythe degree of variation of this germplasm. Agronomic data weresubjected to cluster analysis and several groups were identified,with three groups clustering most of the landraces. Regardingphaseolin variation the C and T banding patterns are the mostfrequent ones, so the origin of the Portuguese beans is thus probablythe Andean region of South America. These results give informationabout the origin, diversity and breeding value of the Portuguesegermplasm, that could be useful to widen the genetic base ofcurrently cultivated bean varieties in Europe.     

Breeding for bean fly resistance in common bean (Phaseolus vulgaris L.): a review

The bean fly (Ophiomya spp) is the most important yield limiting insect pest of common bean in Africa. The insect pest can cause complete crop loss affecting bean production and productivity under epidemic conditions. Effective control of bean fly is essential for sustainable bean production Africa. The overall progress, opportunities and challenges of the bean fly control strategies. The biology and ecology of bean fly and the economic importance of the insect pest is presented as well as the existing controlling strategies, with an emphasis on the breeding on breeding strategies used, research progress achieved challenges and opportunities. In conclusion, significant research progress have been made in breeding for bean fly resistance evident by identification of breeding lines, understanding resistance mechanism and development of breeding strategies. However, there is a need for further research to validate the available information and also explore new breeding methods such molecular breeding which has not been explored at present. Such studies will accelerate breeding for bean fly resistance.     

Genetic diversity among Northwestern Argentinian cultivars of common bean (Phaseolus vulgaris L.) as revealed by RAPD markers

The genetic diversity of 10 commercial cultivars of common beans, developed in Northern Argentina was analyzed based on RAPD markers. Sixteen primers were assayed and among them only 4 showed polymorphisms. A similarity matrix was generated by applying three different association coefficients, Simple Matching, Jaccard and Dice. By the UPGMA method dendrograms were generated and also the principal coordinate analysis was performed. The similarity values found were higher than 40% suggesting that genetic diversity is low. Both cluster analysis and principal coordinates analysis associated commercial cultivars either to the Andean or the Mesoamerican gene pool.     

Multiple genes confer anthracnose resistance in French bean (Phaseolus vulgaris L.) accessions of Garhwal Himalayas

Genetic Resources and Crop Evolution - The Indian Himalayan region is very rich in the genetic diversity of French bean and therefore considered as the secondary centre of origin of French bean....     

Biodiversity of common bean (Phaseolus vulgaris L.) in Honduras, evidenced by morphological characterization

This paper describes findings in the characterization of 300 accessions in a collection of common beans (Phaseolus vulgaris L.) in Honduras. The plant material was collected from 1990 to 1994 (4 years before the damaging Mitch Hurricane) covering most of the Departments of the country and kept at the Escuela Agrícola Panamericana Zamorano. Thirty-two morpho-agronomical characters were evaluated and the results were grouped by classes. The studied accessions showed a marked diversity with high predominance of red and small seeds. The accessions with purple flowers had black seeds and originate mainly from the western area of the country where this type of seed is preferred. Principal Component Analysis shows that clearly defined groups do not exist. The conservation of this diversity is recommended for future propagation, breeding and the investigation of the genetic relationships and other studies.     

Distribution and phenotypic characteristics of common bean (Phaseolus vulgaris L.) nodulating bacteria in diverse soils

ABSTRACT

Bacteria were isolated from the root nodules using common bean as a trap host. Growth and morphological characteristics of the bacterial isolates were described on yeast extract mannitol mineral salts agar and broth media. The results showed that over 67% of the isolates produced extracellular polysaccharide with an entire margin and convex elevation. The others differentiated into cream yellow, cream white and milky white colouration with colony area ranging from 0.8 to 26?mm². The population levels of bacteria nodulating common bean varied in soils and were not affected by the cropping system. However, selected soil parameters greatly influenced the occurrence and distribution of these bacteria. The isolation of indigenous bacteria in all the soils with different cropping systems is an indication that the soils are favourable for nitrogen fixation. Based on the differences in cultural characteristics of the isolates, our data demonstrate the presence of high diversity of bacteria associated with bean nodules.     

Antioxidant activity in common beans (Phaseolus vulgaris L.)

Beans were pearled to evaluate the feasibility of increasing antioxidant activity and phenolic antioxidants. Phenolics were concentrated mostly in the hull fraction at about 56 mg of catechin equivalents per gram of sample. The methanolic extracts of the pearled bean samples were screened for antioxidant potential using the beta-carotene-linoleate and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro model systems. The pearled material, also referred to as milled samples, exhibited antioxidant activity that correlated with phenolic content and inhibited DPPH significantly in a dose-dependent manner. Phenolics and antioxidant activities were also examined in chromatographic fractions of methanolic extracts of manually obtained hulls that represented a model used previously to ascertain antimutagenic activity. Fractions extracted with ethyl acetate/acetone and acetone displayed antioxidant activity, which implies potent free radical scavenging activity with antimutagenic activity.     

Compatibility of crosses between gene pools and evolutionary classes in the common bean (Phaseolus vulgaris L.)

The extent of genetic divergence between the Mesoamerican and Andean gene pools and between evolutionary classes (wild, landrace and bred) in Phaseolus vulgaris was explored. The compatibility of crosses was assessed by the frequency with which pollination was successful and the number of seeds in the resulting pod. Mesoamerican genotypes were more effective as pollinators than Andean genotypes, regardless of the gene pool of the female parent. Though certain individual genotypes were more easily pollinated by genotypes of one or other of the gene pools, there was no consistent tendency for pollinations between genotypes within a gene pool to be more successful than those between gene pools. In crosses among wild and landrace genotypes, the landrace genotypes were more easily pollinated. In those among wild and bred genotypes, the bred genotypes were more effective as pollinators, and the number of seeds per pod was greater in crosses between the evolutionary classes than in those within classes. In crosses among landrace and bred genotypes, those within evolutionary classes had higher success rates than those between classes (47.2% vs. 38.9%), and produced more seeds per pod. However, these results do not represent a major barrier between the evolutionary classes. The hypothesis that dwarf-lethal incompatibility in inter-gene pool crosses is controlled by two complementary dominant genes (the DL-gene hypothesis) was tested by comparing the numbers of normal and abnormal plants in the progeny of three-way crosses, and the ratios obtained were consistent with the hypothesis. It is concluded that there is no biological barrier between the two gene pools and that they are distinct because, by accident of ancestry, they are located in geographically isolated and ecologically distinct areas, with different cultural practices and preferences. Research programmes aimed at transferring desirable traits between the gene pools should therefore be encouraged.     

Population structure and genetic differentiation among the USDA common bean (Phaseolus vulgaris L.) core collection

Genetic diversity data were collected from a large population of common bean (Phaseolus vulgaris L.) landraces representing the United States Department of Agriculture core collection. The data were based on microsatellite data from all linkage groups. A procedure was developed to determine if we collected sufficient marker data to adequately estimated pairwise diversity. The diversity data were used to define populations using distance and model-based approaches. Genetic differentiation and genetic isolation by distance data were collected. Diversity was also compared for markers linked and unlinked to domestication loci. Using a model-based approach, the landraces were divided into the traditional Middle American and Andean gene pools. Diversity was greater for the Middle American gene pool. Six Middle American and three Andean subpopulations were defined, and the Middle American subpopulations exhibited strong geographic identity. Unlike other studies, seed size varied considerably with subpopulations, and a number of the subpopulations contained landraces from multiple common bean races. All of the subpopulations were highly differentiated, with the Middle American subpopulations showing the greatest differentiation. Genetic isolation by distance was observed among the Middle American and Andean subpopulations but not among subpopulations within a gene pool. Within each gene pool, diversity was lower for markers linked to domestication loci.     

Chemical components with health implications in wild and cultivated Mexican common bean seeds (Phaseolus vulgaris L.)

Common bean effects on health have been related to its dietary fiber content and other active compounds. This study assessed the content of flavonoids, coumestrol, phenolic acids, galactooligosaccharides, and phytic acid in wild and cultivated Mexican common bean seeds (raw and cooked) and that of flavonoids, coumestrol, and phenolic acids in germinated bean seeds. The presence of isoflavones in raw bean seeds was not confirmed by the UV spectra. Quercetin, kaempferol, p-coumaric acid, ferulic acid, p-hydroxybenzoic acid, and vanillic acid mean contents were 10.9, 52.3, 10.1, 9.6, 5.4, and 18.2 microg/g, respectively; raffinose, stachyose, verbascose, and phytic acid mean contents were 8.5, 56.3, 5.5, and 11.5 mg/g, respectively, in raw seeds. All compounds were affected by autoclaving, and germination resulted in a de novo synthesis of flavonols, phytoestrogens, and phenolic acids. The impact on health of common bean seed is affected by dietary burden, specific compounds content, and processing. On the other hand, germinated bean seed or beans sprouts may be sources of antioxidants and phytoestrogens.     

Anthocyanin profile of Korean cultivated kidney bean (Phaseolus vulgaris L.)

This investigation was conducted to determine the structures and amounts of anthocyanins obtained from seed coats of kidney bean (Phaseolus vulgaris L.) cultivated in Korea. Anthocyanins in the seed coat of kidney bean were extracted with 1% HCl/20% CH(3)OH, and the crude anthocyanin extracts were purified by semipreparative HPLC. Five major anthocyanins were isolated, and their chemical structures were identified by spectroscopic methods (UV-vis, LC/ES-MS, and 1H and 13C NMR). The structures of these five anthocyanins were elucidated as cyanidin 3,5-diglucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and pelargonidin 3-glucoside. Using RP-HPLC with photodiode array detection, each of the five anthocyanins was separated within 12 min by using a gradient elution. It was proved that the application of RP-HPLC could be an excellent method for determining the composition and contents of anthocyanins in kidney bean. The preponderance of pelargonidin 3-glucoside and delphinidin 3-glucoside are observed in red and black kidney beans, respectively. However, in this study, it is reported for the first time that the contents and composition of anthocyanins in speckled seed depend on the classes of speckle color. The contents of cyanidin 3,5-diglucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, pelargonidin 3-glucoside, and total anthocyanins in seed coats of 16 kidney beans cultivated in Korea were in the ranges of 0-0.04, 0-2.61, 0-0.12, 0-0.17, 0-0.59 and 0-2.78 mg/g of dried seed coats, respectively.     

Polyphenols and antioxidant capacity of seed coat and cotyledon from Brazilian and Peruvian bean cultivars (Phaseolus vulgaris L.)

Seed coats and cotyledons from 25 Brazilian and 3 Peruvian bean cultivars were investigated in relation to their phenolic profiles and antioxidant capacity. Condensed tannins, anthocyanins, and flavonols such as kaempferol and quercetin glycosides were mostly found in seed coats. Cotyledons were rich in phenolic acids, such as ferulic, sinapic, chlorogenic, and other hydroxycinnamic acids. In general, the seed coat color pattern and the type of cultivar showed an important influence on the variability of phenolic profiles and levels, respectively. Total phenolics and antioxidant capacity assessed by the DPPH method were higher in seed coats than in cotyledons. The antioxidant capacity had a significant correlation with condensed tannins for all samples and with total anthocyanins in black and red seed coats, whereas in cotyledons, it was more related to the total phenolic content.     

Phytic acid, phytase, minerals, and antioxidant activity in Canadian dry bean ( Phaseolus vulgaris L.) cultivars

Ten bean cultivars grown in southern Manitoba in 2006 were evaluated for variability in phytate, phenolic, and mineral contents, phytase activity, and antioxidant properties to elucidate the relationship of these components. Phytic acid content and phytase activity varied significantly among cultivars and market classes, ranging from 16.7 to 25.1 g/kg and from 224 to 361 phytase activity unit/kg of sample, respectively. The bean cultivars with total phenolic content ranging from 2.2 to 5.6 g of catechin equiv/kg of sample exhibited significant variation in antioxidant capacity [1.6-11.2 microM Trolox equiv (TE)/g of dry matter] and peroxyl radical scavenging activity (72-158 microM TE/g) using photochemiluminescence and fluorescence assays, respectively. Multivariate data analysis performed on 22 components analyzed in this study using principal component analysis and cluster methods demonstrate that differences in phytase, antioxidant activity, mineral contents, and bioavailability are much larger within market class than among bean cultivars.     

Biotransformation of common bean (Phaseolus vulgaris L.) flavonoid glycosides by bifidobacterium species from human intestinal origin

Bifidobacteria strains from human origin were screened for the specific activity (beta-glucosidase activity) involved in the metabolism of dietary flavonoids. Five strains with high beta-glucosidase activity were selected for further metabolism analyses (high-performance liquid chromatography separations) of flavonoid glycosides occurring in Phaseolus vulgaris L. (common bean) seeds and seedlings. All selected strains were found to be active in the conversion of kaempferol 3-O-glucoside, daidzin, genistin, and glycitin into their aglyconic forms. No metabolites were detected after the fermentation tests with the diglucosidic compound kaempferol 3-O-xylosylglucoside. In addition, to verify the effective bioavailability of flavonoid aglycones, the degradation rates of daidzein, genistein, glycitein, and kaempferol, following incubation with selected strains, were monitored. The results showed that the five selected strains of bifidobacteria, being active in the biotranformation of flavonoid glycosides occurring in common bean seeds and seedlings, could be considered as probiotic dietary adjuncts to improve the nutritional and health properties of flavonoid-based products, comprising hypothetical common bean food derivatives.     

Genetic diversity and population structure of a common bean (Phaseolus vulgaris L.) collection from Calabria (Italy)

Eighty-seven Phaseolus vulgaris landraces, still cultivated in Calabria (Italy), were investigated in order to study the patterns of common bean genetic diversity in this region, to better understand the evolutionary development of beans in Europe and to properly manage these genetic resources. Four American accessions and five Italian varieties were also included. Different markers, such as 12 microsatellites, seed traits, phaseolins and 100-seed weight were combined with different statistical approaches. For each microsatellite, expected (H _e ) and observed (H _o ) heterozygosities, polymorphism information content (PIC), probability of identity (PI) and homozygosity were calculated. Furthermore, in Calabrian group of bean landraces, total (N _a ) and private (N _pa ) number of alleles, observed (H _o ), expected heterozygosities (H _e ) and allelic richness (AR) were calculated. Genetic distances among landraces were estimated using Nei’s coefficient and a cluster analysis using the UPGMA algorithm was performed. The results clearly indicated that: (1) Calabrian germplasm showed a high level of diversity (H _e  = 0.595); (2) Mesoamerican and Andean gene pools were clearly distinguished in Calabrian germplasm, with the Andean gene pool predominating (83 %); (3) Calabrian landraces were largely hybridized within and between the gene pools. A model-based approach, using the STRUCTURE software, was adopted. Six groups, including 4 of Andean origin and one of Mesoamerican origin were identified. Even more interesting, a small group (8 %) showed a distinct genetic structure, in which interspecific hybridizations with runner bean (Phaseolus coccineus L.) could have occurred. Nevertheless, a relatively high proportion of Calabrian bean landraces (12.6 %) was derived from intra and interspecific hybridizations.     

Polyphenols in wild and weedy Mexican common beans (Phaseolus vulgaris L.)

The polyphenolic composition of 62 wild and weedy Mexican bean collections from diverse origins, grouped by their seed coat color, was assessed. According to spectrophotometric analysis, the range of total phenols, condensed tannins, and total anthocyanins presented wide differences. Furthermore, the phenolic acid, flavonoid, and anthocyanin profiles were analyzed using HPLC. Ferulic was the main phenolic acid. Kaempferol and quercetin were the main flavonoids, and the isoflavones daidzein and coumestrol were found in only low levels in few collections. Delphinidin was the main anthocyanidin found, followed by petunidin, cyanidin, malvidin, pelargonidin, and peonidin. The wide variation observed in polyphenolic contents was more related to their genotype than to the color factor. These results show that some wild and weedy beans are good sources of phenolic compounds for use in breeding programs focused on nutrition and health.     

Effects of Azospirillum brasilense on root morphology of common bean (Phaseolus vulgaris L.) under different water regimes

 The effects of inoculation with Azospirillum brasilense Cd on root morphology and growth of common bean (Phaseolus vulgaris L.) were studied under different growth systems and water regimes. The root systems were evaluated by image analysis. In a PVC-tube growth system, inoculation with A. brasilense at 10⁷ colony forming units (CFU) ml^–1 increased root length, root projection area, specific root length (m g^–1) and specific root area (cm² g^–1), as compared with non-inoculated controls, resulting in root systems with longer and thinner roots. Water stress induced similar root responses to those observed after inoculation with A. brasilense. No increase in plant biomass was observed in inoculated plants, suggesting that under the tested growth conditions, a relatively larger amount of resources is required for the maintenance of the thinner roots. In water-stressed potted plants, the effect of A. brasilense on tap root length was inoculum-concentration dependent. At 10⁷ CFU ml^–1 this effect was significant as compared to non-inoculated controls. In a pouch system without water stress, inoculation with A. brasilense at a concentration of 10⁵–10⁷ CFU ml^–1 2 days after germination resulted initially (2 days after inoculation) in an increase in root length (95%) and root fresh weight (66%), but reduced root diameter (20%), compared to controls. At this early stage of growth the distribution of root length among the different root diameter classes changed: the thinner-root classes had the largest proportion of longer roots. Received: 3 January 2000     

Yield and yield components of white bean (Phaseolus vulgaris L.) cultivars affected by boric acid rates and methods of application

To investigate the effect of boric acid on yield and yield components of three white bean cultivars consisted of Jules, G11867, and Shekoofa, a 2-year field split-plot experiment was carried out based on a randomized complete block design with three replications during 2013 and 2014. Boron treatments consisted of 1 – control (no boric acid), 2 and 3 – application of 2 and 4?kg ha^?1 of boric acid by irrigation water, respectively, 4 and 5 – foliar spray of 0.025% and 0.05% of boric acid solutions, respectively, and 6 – combination of 2?kg ha^?1 of boric acid in irrigation water?+?foliar spray by 0.025% boric acid solution. Boron application significantly increased yield and its components in respect to control. The highest grain yields of all cultivars were obtained from application of 2?kg ha^?1 boric acid mixed in irrigation water?+?foliar spray by 0.025% of boric acid solution.     

Effect of nitrogen sources on the yield of common bean (Phaseolus vulgaris) in western Kenya

Depletion of soil nutrients due to continuous cultivation without adequate external fertilization is one of the challenges facing many smallholder farmers in western Kenya. This study was conducted to assess the effects of organic (water hyacinth compost), inorganic (urea) nitrogen (N) sources, and commercial Rhizobia inoculant on the yield of common bean (Phaseolus vulgaris) for two consecutive seasons in the short rains (2013) and long rains (2014). The experiments were laid out in a randomized complete block design and replicated four times. Triple superphosphate was applied to all treatments except those with compost to ensure that the soil had adequate phosphorus (P). Yellow and Rose coco bean varieties grown with urea and inoculated with commercial Rhizobia inoculant gave significantly higher yield of 382 kg ha^?1 and 341 kg ha^?1, respectively in the short rains (SR) season. In the long rains (LR) season bean yield was high in water hyacinth compost (1526 kg ha^?1) and control with non-limiting P (1300 kg ha^?1) treatments. Commercial Rhizobia inoculant did not significantly increase in yield in the SR and LR seasons. There was no significant influence on soil properties after two seasons of continuous cultivation of common bean and application of organic and inorganic fertilizers. These results demonstrate that water hyacinth compost improved bean yield in the LR season. However, longer field testing and economic analysis are required for it to be recommended as a substitute for inorganic N source among smallholder farmers.