Bean Populations Research Articles

Potential Control of Mycotoxigenic Fungi and Ochratoxin A in Stored Coffee Using Gaseous Ozone Treatment

The objective of this study was to examine the effect of treatment of Arabica green coffee beans with gaseous ozone (O3) for the control of ochratoxigenic fungi and ochratoxin A (OTA) contamination by Aspergillus westerdijkiae, A. ochraceus, and A. carbonarius during storage. Studies included (i) relative control of the populations of each of these three species when inoculated on irradiated green coffee beans of different initial water availabilities using 400 and 600 ppm gaseous O3 treatment for 60 min at a flow rate of 6 L−1 and on OTA contamination after 12 days storage at 30 °C and (ii) effect of 600 ppm O3 treatment on natural populations of green stored coffee beans at 0.75, 0.90, and 0.95 water activity (aw) or with additional inoculum of a mixture of these three ochratoxigenic fungi after treatment and storage for 12 days at 30 °C on fungal populations and OTA contamination. Exposure to 400 and 600 ppm O3 of coffee beans inoculated with the toxigenic species showed that there was less effect on fungal populations at the lowered aw (0.75). However, toxigenic fungal populations significantly increased 48 h after exposure and when stored at 0.90 and 0.95 aw for 12 days. All three species produced high amounts of OTA in both O3 treatments of the wetter coffee beans at 0.90 and 0.95 aw. Gaseous O3 (600 ppm) treatment of naturally contaminated green coffee beans had little effect on fungal populations after treatment, regardless of the initial aw level. However, after storage, there was some reduction (26%) observed in coffee at 0.95 aw. In addition, no fungal populations or OTA contamination occurred in the 0.75 and 0.90 aw treatments after exposure to 600 ppm gaseous O3 and storage for 12 days. It appears that under wetter conditions (≥0.90–95 aw) it is unlikely that fungal populations and OTA contamination of stored coffee beans, even with such high O3 concentrations would be controlled. The results are discussed in the context of potential application of O3 as an intervention system for stored coffee post-fermentation and during medium term storage and transport.

Genetic Diversity of Orobanche crenata Populations in Ethiopia Using Microsatellite Markers.

Orobanche crenata is a parasitic weed that causes considerable yield losses on food legumes in Ethiopia and the Mediterranean region. Understanding the genetic diversity of Orobanche crenata using molecular techniques generate useful information in managing the weed through resistance breeding. This study aimed at assessing the genetic diversity of O. crenata populations collected from major faba bean growing areas of Ethiopia. A total of 96 samples were collected from the Orobanche-infested faba bean farmer field. The genetic diversity of the population was studied using 30 O. cumana SSR markers. The results showed that 11 SSRs were functional and transferable markers to study the diversity of O. crenata populations. The average number of alleles, gene diversity, heterozygosity, and polymorphic information content values for the SSR loci were 9.6, 0.82, 0.38, and 0.80, respectively. The pairwise genetic similarity analysis showed the lowest genetic distance between samples collected from South Gondar and South Wollo (0.12) while the highest genetic distance (0.48) was found between South Gondar and North Wollo. The analysis of molecular variance result indicated that the variation among individuals was a major source of genetic variation (55%) followed by within individuals (43%) and among populations (2%) variation. The output of population genetic structure analysis indicated the presence of two major groups irrespective of the area of collection or region of origin. Besides, the outcome of the spatial autocorrelation computation indicated a significant and positive genetic correlation between samples collected under a 28 km radius. In general, the absence of geographic region based genetic structure presumably demonstrates the expansion of the parasitic weed between farming sites upon its recent introduction to the country. Thus, the clear absence of population differentiation warrants screening faba bean population in hot spot area.

QTL mapping of post-processing color retention in two black bean populations.

Several QTL governing color retention in processed black beans were identified by traditional and novel phenotyping methods applied to two black bean mapping populations. When black beans are hydrothermally processed prior to consumption, water-soluble anthocyanins are released from the seed coat, resulting in an undesirable faded brown color in the cooked product. The aim of this research was to develop mapping populations with different genetic sources of color retention in order to identify regions of the bean genome associated with canning quality traits. Two half-sibling black bean recombinant inbred line (RIL) populations segregating for post-processing color retention were developed. These RIL populations were phenotyped for canning quality traits over twoyears and genotyped using the BARCBean6k_3 BeadChip. In addition to traditional phenotyping by trained panelists, cooked beans were also phenotyped using a novel digital image analysis pipeline. Measurements of post-processing seed coat color from both phenotyping methods were compared, and the digital image analysis was shown to outperform the trained panelists. Quantitative trait loci (QTL) for post-processing color retention were detected on six chromosomes, with QTL on Pv08 and Pv11 consistently detected across phenotyping methods, populations, and years. Color retention QTL on Pv08 explained up to 32% of phenotypic variation but were significant over a large physical interval due to low SNP marker coverage. However, color retention QTL on Pv11 also explained a substantial amount of phenotypic variation (r2 ≈ 25%) and mapped to a small genomic region near 52.5 Mbp. The QTL and methods described in this study will be useful for dry bean breeders and food scientists to produce high quality black beans that meet consumer needs.

Selection of snap beans progenies to improve physiological quality of seeds

Research on snap bean seed production is essential for this crop to compete against other species that have better production technologies. This study aimed to select a physiological quality evaluation test for snap beans to improve progeny selection strategies. The experiment was conducted in the Seed Analysis Laboratory at the Federal Institute of Goiano, campus Iporá-GO. Seed from thirteen progenies were evaluated for physiological quality from a breeding program conducted by the genetic breeding department of the State University of Goiás, campus Ipameri. Seeds were evaluated for moisture content, thousand-seed weight, biometry (length, width, and thickness), germination, seedling vigor classification, length and seedling dry mass, emergence in the field, and emergence speed index of seedlings in the field. The genetic variability in the evaluated characteristics indicated that genetic breeding can contribute to a better performance in snap bean seed physiological quality. The germination test, vigor classification, emergence, and emergence speed index of seedlings can be used to design strategies for snap bean population selection that produces more productive seeds.

Serendipitous In Situ Conservation of Faba Bean Landraces in Tunisia: A Case Study

Cultivation of faba bean (Vicia faba L.) in Tunisia is largely based on improved varieties of the crop. However, a few farmers continue to produce local cultivars or landraces. The National Gene Bank of Tunisia (NGBT) recently launched a collection project for faba bean landraces, with special focus on the regions of the North West, traditionally devoted to cultivating grain legumes, and where around 80% of the total national faba bean cultivation area is located. The seed phenotypic features of the collected samples were studied, and the genetic diversity and population structure analyzed using simple sequence repeat markers. The genetic constitution of the present samples was compared to that of faba bean samples collected by teams of the International Center for Agricultural Research in the Dry Areas (ICARDA) in the 1970s in the same region, and stored at the ICARDA gene bank. The results of the diversity analysis demonstrate that the recently collected samples and those stored at ICARDA largely overlap, thus demonstrating that over the past 50 years, little genetic change has occurred to the local faba bean populations examined. These findings suggest that farmers serendipitously applied international best practices for in situ conservation of agricultural crops.

QTL Mapping for Drought-Responsive Agronomic Traits Associated with Physiology, Phenology, and Yield in an Andean Intra-Gene Pool Common Bean Population

Understanding the genetic background of drought tolerance in common bean (Phaseolus vulgaris L.) can aid its resilience improvement. However, drought response studies in large seeded genotypes of Andean origin are insufficient. Here, a novel Andean intra-gene pool genetic linkage map was created for quantitative trait locus (QTL) mapping of drought-responsive traits in a recombinant inbred line population from a cross of two cultivars differing in their response to drought. Single environment and QTL × environment analysis revealed 49 QTLs for physiology, phenology, and yield-associated traits under control and/or drought conditions. Notable QTLs for days to flowering (Df1.1 and Df 1.2) were co-localized with a putative QTL for days to pods (Dp1.1) on linkage group 1, suggesting pleiotropy for genes controlling them. QTLs with stable effects for number of seeds per pod (Sp2.1) in both seasons and putative water potential QTLs (Wp1.1, Wp5.1) were detected. Detected QTLs were validated by projection on common bean consensus linkage map. Drought response-associated QTLs identified in the novel Andean recombinant inbred line (RIL) population confirmed the potential of Andean germplasm in improving drought tolerance in common bean. Yield-associated QTLs Syp1.1, Syp1.2, and Sp2.1 in particular could be useful for marker-assisted selection for higher yield of Andean common beans.

Host density and parasitoid presence interact and shape the outcome of a tritrophic interaction on seeds of wild lima bean

The interaction between the seed beetle Zabrotes subfasciatus and its parasitoid Stenocorse bruchivora, was investigated on seeds of two populations of wild lima bean, Phaseolus lunatus. By manipulating the number of beetle larvae per seed and the presence of parasitoids, we determined how factors related to beetle larvae density, the seed in which they feed and the parasitoid, may interact and affect host and parasitoid survival. Results showed that an increase in larval beetle density had a negative impact on beetle performance. This effect cascaded up to parasitoids, high larval density strongly reduced parasitoid emergence. Also, parasitoid presence resulted in faster beetle development and lower female weight. An interactive effect between larval host density and parasitoid presence affected the number of insects that emerged from the seeds. Beetle performance was better in the bean population with the largest seeds, while parasitoid emergence was the lowest in these seeds. This study shows that the impact of parasitoids on seed beetles is contingent on the interaction between density-mediated (direct mortality) and trait-mediated (e.g. non-consumptive) effects. Indirect trait-mediated effects of natural enemies are likely prevalent across insect communities, understanding their role in driving host-parasitoid interactions can have important implications for biological control.

Malaysia’s Palm Oil Export to India

India is the second-most populous country after China, with an overall population exceeding 1.3 billion. India is the fifth country in the world with the highest import and consumption of world oils and fats. Palm oil has become the main of oil and fats product that is being imported and consumed in India market. India is the major of Malaysia’s palm oil export destination. Malaysia’s palm oil exports to India market continually increases since the last ten years with an average of more than 2 million tonnes a year. This study attempts to analyse factors that influence the export demand of Malaysia’s palm oil to India market. The study applies the ARDL approach for data from the period 1975 – 2018. The study indicates that there are relationships between variables in the short run and long run for the demand of palm oil exports by India. The most significant determinant is attributed to soya bean prices (LPSBR) and population (LPOPI) in both short-run and long run. The export price of palm oil by Indonesia (LCPOPXIR) indicates a positive and significant relationship as Malaysia and Indonesia are competing to penetrate to India market in the long run. However, Malaysia’s export price of palm oil has a negative relationship but insignificant. Thus, the findings suggest for non-price strategies in order to increase exports to India market. Non-price strategies such as an increase of quality and the differentiation of product as well as trade deals are the strategies to increase competitiveness and preferences of Malaysia’s palm oil in India market.

Yield stability in small red inter-racial common bean lines in Kenya

Agronomic performance of new common bean (Phaseolus vulgaris L.) varieties may vary considerably in diverse agro-ecological zones, due to genotype-environment (G x E) interactions. A multi-site evaluation is, therefore, crucial in elite lines selection as it considers simultaneously both yield and stability of performance, making selection of genotypes more precise and refined. This study aimed at assessing the agronomic performance and yield stability of 24 F1.7 small red bean lines, selected for multiple disease resistance, using molecular markers from 16 inter-racial bean populations. The study lines were evaluated in low, medium and high altitude agro-ecological conditions in Kenya. G x E effects for grain yield were highly significant (P<0.001), implying that the agronomic potential of the small red bean lines varied with agro-ecological zones. Tigoni, the high altitude (2130 m above sea level) test site had the highest grain yield (3,809 kg ha-1). There were no significant differences between medium altitude (1820 masl) Kabete (1,100 kg ha-1) and low altitude (1150 masl) Mwea (1,025 kg ha-1) sites. Number of pods per plant was strongly positively correlated with seed yield (r=0.85***), and could be adopted by breeders as an indirect selection method for grain yield. The G x E interaction on grain yield was high (14.4%), implying that most of genotypes should be selected and recommended to specific environments. The high yielding line, KMA13-25-09 (3,385 kg ha-1), was the least stable across sites. Disease severity score for target diseases was low to intermediate regardless of the genotypes and sites.Key words: Disease resistance, Phaseolus vulgaris, severity

Study concerning the main characteristics of climbing bean seeds belonging VRDS, Romania germplasm collection

Since 2010 at the Vegetable Research and Development Station (VRDS) Buzau a program was initiated in order to preserve and valorize local bean population (Phaseolus vulgaris L.) from eastern and southeastern Romania. In 2014 the germplasm collection contained over 150 accessions. This paper presents the comparative study of the main characteristics of 40 climbing bean seed (weight, length, width, thickness, colour and secondary colour distribution). Regarding V(6), the highest values of seed weight (0.84 g) and width (10.83 mm) were registered. Seed length varied between 18.05 (V(7)) and 10.74 mm (V(36)). For V(36) the lowest seed weight (0.3 g) was registered. The highest value concerning the width/thickness proportion was 1.92 (V(7)). More than half of the studied seeds presented two or more colours dispensed around hilum, on half of grain, in streaks or patches. These results show a great variability in the biological material collected and also justify the works concerning the biodiversity preservation for this species.

Dynamics of the Foliar Pigments Content in Some Bean Genotypes, from North-East Romania, under Salt Stress

Phaseolus vulgaris L. is a salt-sensitive species. For this reason, the purpose of the face work was to determine the effect of excess NaCl on the content of the chlorophyll pigments as an indicator of salt stress tolerance. Therefore, in the present study, of the influence of saline solutions of 100 mM and 200 mM NaCl was studied on the content of assimilatory pigments, to 7 local populations of common beans, collected from areas with saline soils, from Nord-East of Romania and grown under greenhouse conditions, at the pots. The experiment is part of a broader research, and the determination of pigment content is only one stage of this research, because and other physiological and biochemical parameters are analyzed. 15 days after treatment the content of chlorophyll a, chlorophyll b and carotenoids pigments showed higher values compared with analyzes performed after 30 days. The overall objective of the research is to contribute to a better understanding of the physiological mechanisms involved in the saline stress tolerance of Phaseolus vulgaris L., identification of local populations of salinity-tolerant beans and their use in breeding programs of this species. As novelty, in the current study, new genotypes were found of bean, from Nord-East of Romania, tolerant to this factor.

Potential for Acanthoscelides obtectus to Adapt to New Hosts Seen in Laboratory Selection Experiments.

Effective pest management strategies for a targeted pest species must rely on accurate, reliable and reproducible estimates of population dynamics. Importance of such approaches is even more conspicuous when assessing pest’s potential to utilize other stored products. Using an experimental evolution approach, we have focused our attention on a common bean pest, the seed beetle (Acanthoscelides obtectus). We looked into the potential to invade and sustain population growth on two suboptimal host plants (chickpeas and mung beans). Such an approach simulates steps of the host-shift process in storages. By analyzing population dynamics during initial encountering with a new host plant, we detected a population drop for both novel hosts. However, transgenerational development in a novel environment resulted in a constant population growth in chickpeas, but not in mung bean populations. Reversal of chickpea selected populations to original host plant has led to a severe decrease in population parameters due to low viability of immatures, while the opposite trend was detected in mung bean populations. This paper highlights the importance of good practice in estimating population dynamics for economically important species. With special emphasis on storage pest species, we discuss how this approach can be useful for estimating invading potential of pest insects.

Genotype x Environment Interactions on Seed Yield of Inter-racial Common Bean Lines in Kenya

Determination of yield stability is critical in identifying new common bean cultivars with either specific or broad adaptation in target environments. This study aimed to assess genotype by environment (G x E) effects on agronomic performance of 78 F1.7 lines selected with molecular markers for multiple disease resistance from 16 inter-racial bean populations. Field trials were conducted in low-, medium- and high altitude conditions in Kenya. Data collected on seed yield were subjected to additive main-effects and multiplicative interaction (AMMI) model to separate additive variance from the G x E interaction and to determine the stability of genotypes across locations. Results showed that G x E effects were highly significant (P01), implying that tested lines behaved differently across the three locations. Better yields were recorded from high altitude Tigoni site while the lowest were from low altitude Mwea site. Yield across sites ranged from 1,518 to 2,748; 1,324 to 3,860; 1,537 to 3,722 and 1,010 to 3,718 kg ha-1 for pinto, red mottled, red kidney and mixed color bean lines, respectively. Number of pods plant-1 was the most strongly correlated to seed yield and could be, therefore, used as an indirect selection criterion for seed yield. The environment was responsible for the largest part of yield variability (86.4%, 84.8%, 82.3% and 49.5% for pinto, red kidney, red mottled and mixed color bean lines, respectively). KMA13-22-21 and KMA13-29-21 were the most stable high yielding lines across locations. Higher yielding lines were the most unstable across sites. Two pinto, four red kidney, 15 red mottled, and two mixed color lines did better than their corresponding checks with yield advantages of 7.6, 14.3, 71.5, and 34.9%, respectively. These lines should, therefore, be selected for further testing and release.

Variabilidad fenotípica en colectas de haba provenientes del Valle Toluca-Atlacomulco, México


 Este estudio se realizó en el ciclo primavera-verano de 2014 en San Mateo Atenco, estado de México, México, con el objetivo de estimar los componentes de varianza y la heredabilidad en 39 cultivares de haba e identificar material genético sobresaliente a partir de caracteres cuantitativos y cualitativos. Se utilizó un diseño experimental de bloques completos al azar con tres repeticiones. Los caracteres cualitativos se describieron de acuerdo con la guía técnica para la descripción varietal en haba del servicio nacional de inspección y certificación de semillas (SNICS). Los resultados mostraron significancia estadística (p≤ 0.01) entre cultivares para cada carácter cuantitativo. La heredabilidad en sentido amplio varío de 30.7 a 99%. El mayor rendimiento de semilla se registró en las colectas identificadas como T8 (4.16 t ha-1), T5 (3.9 t ha-1) y T 27 (3.8 t ha-1). El análisis de componentes principales explicó 65.2% de la variación total original y en éste se observó que el rendimiento se correlacionó positiva y significativamente con número de vainas, peso de vaina y peso de semilla. En el análisis de conglomerados se formaron cuatro grupos, de los cuales el tercero de éstos incluyó a las poblaciones de haba con los mejores descriptores agronómicos evaluados.

Phenotypic multicarter selection approach to predict genetics applied in the segregating generations F2, F3 and F4 of common black beans

The objective of this work was to apply the phenotypic multicarter selection and predictive genetic for the attributes of the yield of common black bean seeds in the segregating generations F2, F3 and F4.The experimental design was augmented blocks, where the BRS Esplendor (BE), BRS Supremo (BS) and IPR Tiziu (IT) genotypes were used as controls arranged in four replicates, the other treatments were organized in a unique way in the experiment, the F2 segregating generation being represented by 36 common black bean populations, F3 segregating generation composed of 72 families and the F4 segregating generation formed by 44 families. The multicarter phenotypic index provided the simultaneous selection for the number and mass of seeds per plant, independent of the segregating generation of common black bean.Multicarter genetic variation is superior for the F3 segregating generation, with pronounced environmental effects on the F4 generation.The F4 segregating families express superiority to the genetic gain and magnitude of superior genotypes in relation to the commercial controls, where high genetic increase is exposed between the F3 to F4selection.The use of the phenotypic index expresses applicability to the selection of common black bean genotypes to increase seed yield.

GENETIC DIVERSITY AMONG AND WITHIN BRAVE BEAN (Capparis flexuosa L.) POPULATIONS ASSESSED USING RAPD MARKERS

ABSTRACT Brave bean (Capparis flexuosa L.) is a Caatinga species that is used as forage, mainly during the dry season when some plant species lose their leaves. The aim of this study was to assess genetic diversity within and among brave bean populations using Random Amplified Polymorphic DNA (RAPD) markers. Brave bean leaves were collected from 30 accessions in the following municipalities of Paraíba state, Brazil: Barra de Santa Rosa (BSR), Cuité (C), São João do Cariri (SJC), Damião (D), Baraúna (B), and Picuí (P). DNA extraction followed the standard methodology of CTAB with modifications. RAPD analyses were carried out using 18 primers, and polymorphism of the amplified DNA fragments was visualized using agarose gel electrophoresis. Data were used to calculate Jaccard Similarity Coefficient values, which were then used to group samples with the Unweighted Pair Group Method with Arithmetic Mean. Cophenetic Correlation Coefficient, Stress, and Distortion Coefficient values were also calculated from these analyses. Band polymorphism was generated with 14 primers, but the sampled populations showed low numbers of polymorphic loci (27 in BSR, 18 in C, 7 in SJC, 9 in D, and 0 in B and P). The highest polymorphic information content was found in samples from the BSR (9 groups), C (22 groups), SJC (7 groups), and D (6 groups) municipalities. In the interpopulation analysis, 34 groups were formed, the matrices of which showed high cophenetic correlations (0.95 to 0.98), but low stress (12.9 to 17.45%) and distortion (3.05%). Therefore, results showed that there was genetic variability both among and within brave bean populations.

Research Article Genetic control and selection of common bean parents and superior segregant populations based on high iron and zinc contents, seed yield and 100-seed weight

The objectives of this study were to select promising common bean populations for high iron and zinc contents (FeC and ZnC), seed yield and 100-seed weight, to study the genetic control of these traits and to select parents for high FeC and ZnC based on a diallele analysis. Fifteen populations were obtained from crosses among six parents selected for high FeC and ZnC using a complete diallel scheme. The 15 populations were evaluated together with two control cultivars/lines (Perola and Pirata 1). The following traits were evaluated: FeC and ZnC in four environments/generations and seed yield and 100-seed weight, in three environments/generations. Individual and joint analyzes of variance were performed for the four traits and individual and joint diallel analyzes for FeC and ZnC. Significant differences were found among populations for all traits, which demonstrates genetic variability that can be exploited. For FeC, the additive effects were more important and the white seeded line G 2358 stood out for high general combining ability (5.63), being for this reason indicated as a parent. For ZnC, both additive and non-additive effects were important. The populations selected as simultaneously superior for the four traits were Porto Real x G 2358 and BRSMG Majestoso x G 2358, with at least one parent with carioca seeds; and BRS Requinte x BRSMG Majestoso, Porto Real x BRS Requinte and Porto Real x BRSMG Majestoso, with carioca seeds. The BRS Requinte x G 2358 population is recommended to obtain lines with high FeC and ZnC.

Seleção multivariada entre e dentro de populações mutantes de feijão

A indução de mutação é estratégia amplamente utilizada nos programas de melhoramento de plantas, e proporciona a criação de variabilidade genética para muitos caracteres de importância agronômica. O objetivo do presente trabalho foi selecionar entre e dentro de populações mutantes de feijão (Phaseolus vulgaris L.) promissoras agronomicamente, nos anos agrícolas 2009/10 e 2010/11, em Lages, SC. Foram avaliadas 40 populações mutantes derivadas de radiação gama de 60Co, nas doses de 100 e 200 Grays. Os genótipos submetidos à mutação induzida foram Pérola, Iapar_81, IPR Uirapuru e IPR Chopim. O delineamento utilizado foi em blocos ao acaso, com três repetições. Foi efetuada análise de variância multivariada e análise discriminante canônica para a exploração das hipóteses. Contrastes multivariados entre as populações mutantes e suas populações originais foram efetuados para testar as hipóteses. A análise de variância multivariada revelou efeito significativo das populações mutantes aninhado aos anos agrícolas. Foi detectada, também, variabilidade dentro das populações mutantes. Estes resultados evidenciam a eficiência do agente mutagênico na criação de variabilidade genética. As populações mutantes selecionadas foram PMP_100 e PMC_200 por apresentarem desempenho promissor em relação aos caracteres diâmetro do caule, massa de mil grãos e rendimentos de grãos. Dentro das populações mutantes selecionadas foi detectada variabilidade genética que pode contribuir para seleção efetiva. As populações PMP_100 e PMC_200 devem ser conduzidas e ainda selecionadas, planta a planta, para obtenção de genótipos promissores.

Linkage fine-mapping and QTLs affecting morpho-agronomic traits of a Mesoamerican × Andean RIL common bean population

This paper proposes the construction of a genetic linkage map with 376 recombinant inbred lines (RILs) derived from a cross between Mesoamerican × Andean common bean (Phaseolus vulgaris L) parents based on single nucleotide polymorphism (SNP) markers; and to detect quantitative trait loci (QTLs) associated with seven morpho-agronomic traits: number of days to flowering (DF), number of days to maturity (DM) or crop cycle; plant architecture (ARC); seed yield (YLD); degree of seed flatness (SF); seed shape (SS); and 100-seed weight (SW). A total of 3060 polymorphic SNP markers were used and 2041 segregated at a 1:1 ratio in the RIL population, as expected. These markers were subjected to linkage analysis in each chromosome. The genetic linkage analysis resulted in linkage maps with a total of 1962 markers spanning 1079.21 cM. A total of 29 QTLs associated with seven morpho-agronomic traits were detected on the 11 chromosomes, which explained between 3.83 and 32.92% of the phenotypic variation in DF. A total of 18 candidate genes associated with the detected QTLs were identified and related with biological processes, molecular functions and cellular components.

Variance components and heritability of yield and yield-related traits in tepary bean (Phaseolus acutifolius)

The extent of variance and heritability of traits influence the response to selection in crop breeding programs. The objective of this study was to determine variance components and heritability in tepary bean (Phaseolus acutifolius A.Gray) populations to identify promising genotypes for strategic breeding or direct production. Fifty genetically diverse tepary bean genotypes were evaluated under two contrasting environments using a 5 × 10 alpha lattice design with two replications. Results showed significant (p ≤ 0.05) differences among genotypes (G), environment (E) and G × E interaction for most of the studied traits. Phenotypic coefficient of variation values were higher than genotypic coefficient of variation for the studied traits, indicating greater contribution of genetic and environmental components influencing phenotypic variation. High broad-sense heritability and genetic advance were observed for grain yield (GY) and harvest index (HI), indicating better selection response for these traits in the population. Path coefficient analysis indicated that direct selection for HI could increase genetic gains for GY in tepary bean. Genotypes G40020, G40023, G40084, G40135, G40139, G40140, G40144A, G40145, G40157, G40159, G40173A, G40237 and G40284 exhibited better yield and yield components and were selected for breeding or population development in tepary bean.