Influence of water stress and common bean genotypes on biological aspects of Chrysodeixis includens and Trichogramma pretiosum

A field experiment was conducted to evaluate soil acidity tolerance of 25 common bean (Phaseolus vulgaris L.) genotypes on lime-treated and lime-untreated acid soils. The twenty-five common bean genotypes were tested in a randomized complete block design with two replications per treatment in 2009 in western Ethiopia. Morpho-agronomic parameters were recorded to evaluate the genotypes. Multivariate methods, including principal component and cluster analysis were used to assess the patterns of morpho-agronomic variation to group the genotypes into distinct categories. The genotype bi trait (GT) bi-plot was used to identify the best traits that are important to identify tolerant genotype and to know the relationships between traits and genotypes. The principal component analysis indicated that the first three principal components contributed 64.6 and 66.1% of the total variability among the 25 common bean genotypes grown on the lime-untreated and lime-treated soils, respectively. Among the measured traits, plant height, number of pods per plant, days to pod setting, grain yield, days to flowering and maturity, biomass yield, and 100 seed weight were the parameters that most significantly caused the variations among the genotypes. Genotype by trait (GT) bi-plot led to grouping of the tested genotypes into four categories based on PC1 and PC2 values and also enabled to identify traits such as number of pods per plant, plant height, pod length, 100 seed weight, and grain yield, which were found to be the most responsive characters in evaluating the genotypes for tolerance to soil acidity. The cluster analysis led to classification of the 25 common bean genotypes in to four groups, the first group (cluster) of which contained four genotypes of BILFA material (new BILFA 38, new BILFA 58, New BILFA 61, and new BILFA 60) that outperformed genotypes in the other group (clusters) when grown on lime-untreated acid soil. In conclusion, the results of this study have revealed that multivariate analysis can be used as an indirect method of selecting high-yielding common bean genotypes having the most important desirable traits that contribute to soil acidity tolerance.

A rapid and reliable detached-leaf technique was developed for screening common bean (Phaseolus vulgaris) genotypes against angular leaf spot (ALS) disease caused by Pseudocercospora griseola. It is helpful to differentiate between susceptible and resistance common bean genotypes. Detached leaves of common bean tested genotypes were inoculated by immersing them into a spore suspension followed by placing into petri dishes at room temperature on cotton moistened with tap water. After 10-day incubation, the leaves were monitored for symptom development. This screening method was effective to determine the pathotype of P. griseola isolates on a set of ALS differential common bean genotypes. With this specific screening technique, all known sources of ALS resistance genes, including MEX-54, BAT332, and AND277 exhibited resistant reactions to ALS and showed no reaction and symptom development following inoculation with P. griseola isolates collected from Ethiopia. However, all other common bean genotypes tested together with genotypes known for their susceptibility with reaction scores 4 to 9 developed lesions in the interveinal regions of the leaves. Hence, the proposed simple and rapid screening technique was efficient, low-cost, and able to differentiate between resistant and susceptible common bean genotypes. It can be used for screening in marker-assisted gene pyramiding and backcrossing programs to facilitate early selection of seedlings in segregating progenies. Key words: Detached leaf, Pseudocercospora griseola, genotype screening.

Common bean (Phaseolus vulgaris L.), besides being an agricultural product that can be consumed as fresh vegetable, is a significant legume widely being planted in both Turkey and world. Because of having different usage areas, it is being considered as a valuable plant for human nutrition, trade and in many respects. In this study, we aimed at genetically characterization of the local and registered common bean genotypes and population structure of genotype groups belong to these common bean genotypes in Turkey. For this purpose, total 102 common bean genotypes including 93 local genotypes from 8 provinces, 7 cultivars and 2 reference cultivars were analyzed by 13 fluorescent SSR markers. As the result of the study, it was determined that the total SSR allele number was 192 and the average allele number was 14.8. While it was found that there were no synonymous genotypes, the highest heterozygosity rate was determined in three loci. Factorial correspondence analysis partially demonstrated substructure among common bean genotype groups. Structure analysis showed the same results as the Nm values and the Fst values. In the study, it was observed that SSR markers could be easily used in the molecular studies of common bean germplasm. The obtained results will be able to be used at the conservation, utilization of local common bean genetic resources and at the marker assisted selection studyings.

Common bean is the most important pulse crops worldwide and in Ethiopia for its multipurpose uses. However, common bean production and productivity is mainly constrained by common bacterial blight (CBB) and angular leaf spot (ALS) diseases. Identifying and using resistant common bean genotypes is the best option to reduce the impact of such bacterial and fungal diseases. Field experiments were carried out to evaluate the genetic resistance of 25 common bean genotypes as treatments to CBB and ALS diseases, and agronomic performances at Haramaya and Melkassa, Ethiopia, during the 2019 and 2020 main cropping seasons. The treatments were arranged in a 5 × 5 triple lattice design with three replications. Data on disease intensity, growth, grain yield and yield components were recorded. Analysis of variance indicated significant (p < 0.0001) variations existed among the genotypes for diseases intensity, grain yield and yield components. Eight genotypes, namely DAB-388, DAB-478, DRKDDRB-70, DRKDDRB-81, NUA-225, NUA-517, NUA-536 and NUA-577 attained relatively low disease severity, AUDPC and disease progress rate next to the checks Zoasho (DAB-96) and Gorossa (Biofort large seed-5) to both common bean diseases regardless of locations and seasons. The genotype DAB-525 showed a moderately resistant reaction to both CBB and ALS, and the other genotypes demonstrated variable disease resistance reactions at both locations and in the two cropping years. Similarly, genotypes DAB-388, NUA-225, NUA-517, and NUA-577 relatively executed well for grain yield and yield components at both experimental fields in the 2019 and 2020 main cropping seasons. Disease severity and grain yield variably and negatively associated with reaction groups of genotypes evaluated for reaction CBB and ALS diseases. In the study, resistance to CBB and ALS diseases and good agronomic performing common bean genotypes were identified which could be important for smallholder and commercial bean production in the study area and other similar agro-ecologies in Ethiopia. It is suggested that a large number of common bean accessions should be evaluated in CBB and ALS hot spot agro-ecologies of Ethiopia for more sources of resistance and better agronomic advantages.

Salinity stress significantly threatens seed germination, plant growth, and agricultural productivity, necessitating effective mitigation strategies. This study evaluates the potential of salicylic acid (SA) pretreatment to alleviate the detrimental effects of salinity on common bean (Phaseolus vulgaris) genotypes. SA, a phenolic plant hormone, is crucial for regulating growth, stress responses, and essential physiological processes, including seed germination and ion transport. Previous research has established the general benefits of SA in enhancing stress tolerance, but the specific mechanisms and effects on common bean genotypes remain underexplored. This research focuses on the impact of salinity on the germination and seedling growth of various common bean genotypes, the efficacy of SA pretreatment in enhancing these genotypes' tolerance to salinity stress, and the underlying physiological and biochemical mechanisms, particularly involving the antioxidant defense system. The research was conducted in two phases: germination and seedling growth. Ten genotypes and two commercial varieties were exposed to varying salinity levels alongside SA concentrations to assess germination performance. Subsequently, six genotypes and one variety were evaluated for seedling growth under controlled and salt stress conditions (100 mM and 200 mM NaCl), with SA treatments at 0, 0.5, and 1 mM. Results revealed that salinity severely impaired germination traits, which were significantly enhanced by SA pretreatment. During the seedling growth phase, salinity stress resulted in reduced protein, chlorophyll, and carotenoid content, decreased potassium (K⁺) levels, and diminished water content, while increasing electrolyte leakage, malondialdehyde (MDA) levels, sodium (Na⁺) concentrations, enzyme activities, and proline levels. Importantly, SA pretreatment elevated chlorophyll and protein concentrations, improved water retention, and moderated K⁺ and Na⁺ levels, including their ratios under stress conditions. SA pretreatment also significantly enhanced the antioxidant defense system, reducing oxidative damage induced by salinity stress. Principal component analysis (PCA) successfully categorized the genotypes into semi-tolerant, tolerant, semi-sensitive, and sensitive classes based on their stress responses. Notably, the Jules variety exhibited exceptional resilience during both germination and seedling growth stages, indicating its potential as a superior candidate for cultivation in salt-affected regions. This study highlights SA pretreatment as an effective strategy to enhance salinity stress resilience in common bean genotypes. The novelty of this work lies in the detailed elucidation of SA's role in modulating antioxidant defenses and ion homeostasis in different genotypes, providing new insights into breeding programs and agricultural practices aimed at improving crop resilience and productivity in increasingly saline environments.

The objective of this work was to evaluate the genetic variability of common bean (Phaseolus vulgaris) genotypes of different grain types as to macro- and micromineral concentrations, as well as to select superior genotypes by the multiplicative index. A total of 22 common bean genotypes were evaluated in experiments carried out in the dry and rainy seasons. The concentration of six minerals (potassium, phosphorus, magnesium, iron, zinc, and copper) was determined, and the multiplicative index was applied to individual and combined experiments. There was a significant effect of the genotype × environment interaction on the concentration of all minerals, and, when the genotype effect was decomposed into grain types, the genotypes differed as to the concentration of three or more minerals. There is genetic variability in the concentration of macro- and microminerals in the common bean genotypes evaluated in the dry and rainy seasons. In the combined experiments, high heritability estimates (≥ 62.60%) and a greater total genetic gain (283.59%) are observed. The multiplicative index applied to combined experiments allows the selection of superior common bean genotypes of the following grain types: red (Amendoim comprido and Light Red Kidney), cranberry ('BRS Executivo' and 'Hooter'), and carioca ('IPR Siriri'), which have high phosphorus and iron concentrations; Amendoim comprido also stands out for its high potassium concentration.

Yield of common bean (Phaseolus vulgaris L.) is highly constrained by water deficit especially when this occurs during the reproductive development. The purpose of the study was to determine the association of the morphophysiological traits with water stress and how this affects grain yield in common beans. A field experiment involving eight common bean genotypes and three water regimes (50 %, 75 %, and 100 % of crop evapotranspiration) was conducted at National Irrigation Research Station, Mazabuka district during the 2012 growing season. A Split plot design with four replications was used; with soil moisture regime (main plot) and the genotypes (subplot). Based on variation in water stress tolerances, 8 test genotypes - Gadra, KE 3, KE 4, ZM 4488, SER 76 SER 180, SER 89 and CAR-ZAR were used. Water stress treatments were imposed at pre-flowering stage and was discontinued after 43 days when the crop was in its late reproductive stage. Significant differences were found among genotypes for Chlorophyll a (Chl a), Chlorophyll b (Chl b), Total Chlorophyll, Relative water content, Grain yield, Number pods per, Seed weight, Seeds per pod and Days to 50 % flowering under the three water stress conditions. The grain yield in normally irrigated condition (2191.3 kg ha-1) was 60 % higher than in high water stress condition (866.2 kg ha-1), while in the low water stress condition (1078.3 kg ha-1), the reduction in grain yield was 50.8 %. There were significant genotype by environment showing that the genotypes behaved differently under the different growing conditions. Results suggested that Gadra, KE 4, ZM 4488, and SER 180 were water stress tolerant while the SER 89, CAR-ZAR, KE 3 and SER 76 were water stress sensitive genotypes. These results suggest that a selection method based on 100 SW, Chl a, Chl b, and NPP can be used in breeding for bean genotypes to water stress.

Drought stress is widely recognized as a highly detrimental abiotic stress factor that significantly impacts crop growth, development, and agricultural productivity. In response to external stimuli, plants activate various mechanisms to enhance their resistance or tolerance to abiotic stress. The common bean, a most important legume according to the FAO, serves as a staple food for millions of people worldwide, due to its rich protein, carbohydrate, and fiber content, concurrently, and water scarcity is the main factor limiting common bean production. The process of domestication and on-farm conservation has facilitated the development of genotypes with varying degrees of drought stress resistance. Consequently, using landraces as biological material in research can lead to the identification of variants with superior resistance qualities to abiotic stress factors, which can be effectively integrated into breeding programs. The central scope of this research was to find out if different geographic origins of common bean genotypes can determine distinct responses at various levels. Hence, several analyses were carried out to investigate responses to water scarcity in three common bean genotypes, M-2087 (from the Mesoamerican gene pool), A-1988 (from the Andean gene pool) and Lechinta, known for its high drought stress resistance. Plants were subjected to different water regimes, followed by optical assessment of the anatomical structure of the hypocotyl and epicotyl in each group; furthermore, the morphological, physiological, and biochemical parameters and molecular data (quantification of the relative expression of the thirteen genes) were assessed. The three experimental variants displayed distinct responses when subjected to 12 days of water stress. In general, the Lechinta genotype demonstrated the highest adaptability and drought resistance. The M-2087 landrace, originating from the Mesoamerican geographic basin, showed a lower resistance to water stress, compared to the A-1988 landrace, from the Andean basin. The achieved results can be used to scale up future research about the drought resistance of plants, analyzing more common bean landraces with distinct geographic origins (Mesoamerican/Andean), which can then be used in breeding programs.

&lt;p class="Style"&gt;Production of common bean (&lt;em&gt;Phaseolus vulgaris&lt;/em&gt; L.) is often limited by the low soil fertility (LF). Identification of common bean genotypes adapted to LF may be a feasible strategy to overcome the poor plant growth and production in NP-deficient soils. Eight bean genotypes samples/derived from International Center for Tropical Agriculture (CIAT) and three local common bean cultivars were eval­uated in low soil fertility (LF) and recommended fertilizers (RF) at three locations representing high (Mashwarah), medium (Shaban) and low (Al-Qaidah) rainy seasons at Southern Highland Region (SHR), Ibb, Yemen in 2011, 2012 and 2013 following a completely randomized block design, arranged as split plot with either (LF) or (RF) as the main plots and the genotypes as sub plots. Three replications were used. The LF plots was absolute control, it did not receive any fertilizer (LF) and in (RF) plots, it received only 34.5 kg N and 92 kg P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; kg. The common bean genotypes varied in phenotypic, nutrient efficiency traits and low fertility tolerant indices. The genotypes G2381B, MIB-156, BFB-140, BFB-141 performed favorably under both (RF and LF) environments. These genotypes were associated with higher values of pod number/plant, seed number/plant and 100 seed weight and leaf area, root nodules mass, shoot mass and root mass, shoot mass, physiological, nutrients and recovery efficiency and geometric mean percent (GMP), mean percent (MP) and susceptible tolerant index (STI) and low values of agronomy efficiency, percent of reduction (PR), low fertility susceptible index (LFSI) and tolerant (TOL). The results also showed that high and significant positive correlation of low fertility yield (LFY) and recommended fertility yield (RFY) with seed number/plant and 100 seed weight, NP recovery and use efficiency, geometric mean percent (GMP), mean percent (MP) and susceptible tolerant index (STI) under LF or RF. These correlations indicates that direction selection for yield under LF or RF would result into improved LF tolerant genotypes. Using phenotypic, nutrient efficiency traits, low fertility tolerant indices and stability indices criteria, only G2381B, MIB-156, BFB-140, BFB-143 and BFB-144 showed high average of yields, with &lt;em&gt;b&lt;/em&gt;-value of 1.00 and a very low standard deviation (s&lt;sup&gt;2&lt;/sup&gt;d) approaching zero, low ecovalence value (W) and highly significant coefficient of determination (r&lt;sup&gt;2&lt;/sup&gt;). However, the regression coefficients indicating stability (&lt;em&gt;b&lt;/em&gt;’s) and residuals were highly correlated with slopes (r = 0.943; P &amp;lt; 0.001) and coefficient of determination (r = 0.711; P &amp;lt; 0.001) and equivalent value (r = 0.809; P &amp;lt; 0.001), respectively. Thus the data collected from three locations x three years can be used to select low fertility tolerant (or ‘stable’) genotypes. Such low fertility tolerant genotypes would be better suited for poor farmers in the SHR-Ibb and other similar production regions in Yemen.&lt;/p&gt;

Common bean ( Phaseolus vulgaris L.) is consumed worldwide and is the third most important food legume after soybean and groundnut. The aim of this study was to evaluate plant growth, N 2- fixation, C accumulation and water use efficiency of 63 common bean genotypes grown in Malkerns, Eswatini under field conditions using the 15 N and 13 C natural abundance techniques. The data revealed marked (p ≤ 0.05) differences in shoot dry matter (SDM) yield, N concentration and content, δ 15 N, the proportion of N derived from symbiotic fixation (%Ndfa) and the N-fixed among the 63 common bean genotypes. Common bean plants’ %Ndfa values ranged between 19.6-88.4%, contributed 2.7-66.8 kg N-fixed ha -1 to the soil, while soil N-uptake ranged from 3.7-54.01 kg ha -1 . Out of the 63 test genotypes, 40 genotypes obtained more N from the soil than from symbiosis, implying that the N 2 -fixing efficacy of the microsymbionts nodulating common bean in Malkerns were low. The results further revealed shoot δ 13 C values ranging from -30.11‰ to -26.33‰, indicating differences in plant water use efficiency amongst different common bean genotypes. There was a significant positive correlation between δ 13 C and N content (r=0.25**), and also between N-fixed and shoot dry matter (r = 0.88***), indicating a functional link between N 2- fixation and photosynthesis. Taken together, the findings indicate that, increased N 2 -fixation is linked to improved photosynthetic activity, plant growth and water use efficiency in the bean plants.

Evaluating genetic variability among genotypes is vital for identifying superior genotypes because selecting parents who create segregating populations is critical in breeding programs. The current study was done at Areka Agricultural Research Center during the 2020/21 major cropping season, with the goal of estimating genetic diversity and character connection among 25 common bean genotypes. The experiment consisted of two replications of a 5 x 5 simple lattice design. Data were obtained on 12 quantitative parameters, and the analysis of variance revealed extremely significant variations between genotypes for all characters. It demonstrated that genotypes vary significantly. GCV and PCV were highest in plant height, number of pods per plant, biological yield, number of seeds per plant, and seed yield, while lowest in days to flowering and days to maturity. Plant height, number of pods per plant, number of seeds per plant, biological yield, and seed yield all showed significant broad-sense heritability (H2) and high predicted genetic advance as a percentage of mean GAM. This suggested the presence of additive gene activity in the inheritance of these traits. The number of major branches per plant, biological yield, days of 50% flowering, hundred seed weight, and harvest index all show a highly substantial and positive link with seed yield at both genotypic and phenotypic levels. The biological yield and harvest index both have a strong positive direct effect on seed output. As indicated, these traits could be utilized for selection to increase seed output. Based on the D2 value, 25 common bean genotypes were divided into four clusters. Clusters I and IV had the greatest inter-cluster distance (766.78), whereas clusters I and II had the smallest (53.78). Breeding programs could use genotypes from distant clusters to increase variety. Thus, the enormous genetic variation among common bean genotypes must be evaluated for use in common bean breeding efforts.

Cultivated common bean (Phaseolus vulgaris L.) and tepary bean (Phaseolus acutifolius A. Gray) genotypes possessing desirable agronomic traits were hybridized. The F1 hybrids were backcrossed twice with the common bean (i.e., recurrent backcrossing). Also, alternate backcrosses with common and tepary beans (i.e., congruity backcrossing) were carried out. Embryo culture was necessary for all initial interspecific crosses, and its requirement was proportionally lower when the common bean was used as the recurrent parent and as the last parent of congruity backcrosses. Modification of the embryo culture technique was necessary to produce congruity hybrids. Effects of both tepary and common bean genotypes on the success rate of hybridization were observed. Tepary accession G 40001 and common bean cultivar ICA Pijao facilitated interspecies hybridization. Growth of hybrid embryos before rescue, recovery of mature hybrid plants, and the vigor and fertility of F1 hybrids all increased with increased recurrent and congruity backcrosses and intermatings between male-sterile F1 and selected fertile F2 plants of the third and fifth congruity backcrosses. Introgression of tepary genes was verified by means of seed protein electrophoretic analysis and morphological markers. The results suggest that congruity backcrossing can help to gradually reduce or overcome P. vulgaris x P. acutifolius hybridization barriers such as genotype incompatibility, early embryo abortion, hybrid sterility, and lower frequencies of hybridization.

For successful plant breeding in any crop species, the importance of diversity in the available germplasm population is known and established. Thirty-two common bean (Phaseolus vulgaris) genotypes from the IRAD gene bank in Cameroon were evaluated for divergence in terms of their morpho-agronomic traits, fungal disease resistance, and bacterial disease resistance to assess the opportunity for genetic improvement of the crop. The trait associations were estimated using correlation coefficients and genotypes were classified into groups using cluster and principal component analyses. Seven qualitative and 16 quantitative traits comprising growth, phenological, yield, and disease variables were evaluated in this study. The qualitative markers revealed the degree of polymorphism among the 32 common bean genotypes. The number of phenotypic classes per character (Na) ranged from 2 to 18, with an average of 5.14. The expected gene diversity (He) ranged from 0.37 to 0.93 (mean = 0.56). The number of effective phenotypic classes (Ne) ranged from 1.82 to 14.22, with a mean of 3.85. An extensive range of variation was evident for the majority of traits, highlighting their utility for characterizing common bean germplasm. Many qualitative traits, including seed coat color, seed shape, and seed size, and also some quantitative traits of economic importance including seed yield, were found to be highly variable within the collection, with the MAC55 genotype displaying the highest yield (32.65 g per plant). Four genotypes, namely MAC55, BOA-5-1M6, FEB 192, and Banguem showed resistance to the two main common bean diseases, angular leaf spot and common blight. We detected highly significant correlations among several traits related to yield. A high broad-sense heritability was found for most of the quantitative traits. We carried out two-dimensional principal component analysis and used hierarchical clustering to group the analyzed germplasm according to their phenotypic similitudes. The evidence of agro-morphological diversity in the present collection and the identification of discriminant characters between the available germplasm through the use of PCA analysis have significant implications for establishing breeding schemes in common bean.

Genetic relationships among common bean (Phaseolus vulgaris L) genotypes using ISSR markers

The common bean (Phaseolus vulgaris L.) is an important source of protein and minerals. It supplies all of the iron that humans require for metabolism and provides 25% of the daily requirements of magnesium and copper as well as 15% of potassium and zinc. The objective of this study was to determine the influence of the environment on iron and zinc concentrations and the performance of common bean genotypes. The experiments were conducted in the horticulture units at the Sokoine University of Agriculture (Morogoro) and Madiira-Arusha. A randomized, complete block design with three replications was used for 20 common bean genotypes. The leaves and seeds were collected at early flowering and at maturity and analyzed for iron and zinc concentrations, respectively. Several yield characteristics were measured, including the time required to reach 50% flowering and 85% maturity, the number of seeds to pod ratio, the number of pods to plant ratio, the 100 seed weight and the seed yield. Data analysis was performed using ANOVA and the mean was separated by Duncan’s multiple range test and correlation techniques. The tested genotypes exhibited significant (p<0.05) differences in iron and zinc concentrations in the leaves and seeds of plants from both locations, with plants from Madiira-Arusha having the largest differences. The leaves showed higher levels of iron and zinc than the seeds. We observed a correlation between the concentration of Fe and Zn in both leaves and seeds (r = 0.507*** and r = 0.495*, respectively). In addition, there were significant differences (p<0.05) in the yield characteristics between genotypes of plants from both locations. These results suggest that environmental effects play a role in genotype levels of Fe and Zn in both leaves and seeds