Screening of Common Bean Cultivars (Phaseolus Vulgaris L.) for Drought Tolerance – 1 (Published)
Drought is increasingly becoming a serious challenge reducing common bean productivity in Lesotho. A study was conducted in Lesotho with the object of (1) verifying the differences among common bean cultivars in response to induced water deficit stress, (2) evaluating common bean cultivars against different concentration levels of Polyethylene glycol which induces drought stress in germinating seed and seedling growth and (3) identifying cultivars of common beans tolerant to drought stress and rank top performing accordingly. Complete Randomized Design with three replications and 28 treatments were employed in the laboratory experiment. Treatments were seeds of common bean cultivars obtained from Department of Agricultural Research in Maseru, Lesotho and four different concentrations of PEG-6000. Parameters measured were germination percentage, germination stress index, plumule length, radicle length, plumule fresh and dry weight and radicle fresh and dry weight. Significant differences (P<0.01) among cultivars of common beans in relation to induced procedure of determining drought tolerance as described by Michel and Kaufiman (1973) was followed. Data generated from the experiment were subjected to ANOVA using Genstat Version 14. Mean separation was done using LSD. The results revealed that gifferences exit among bean cultivars.Different concentrations of PEG created highly significant (P<0.01) different environments for common bean cultivars. Interactions of common beans and PEG concentration created highly significant different (P<0.01) environments in which seed germinated and seedlings grew. Kranskop and Small white haricots cultivars obtained highest values in five drought stress indices out of eight measured, followed by CAP 2000, Mkuzi, Nordak, RS7 and DBS 840 cultivars with highest values in four drought stress indices, lastly followed by PAN 148, PAN 9213 and DBS 310 in three drought stress indices.
Keywords: Cluster analysis, Common bean, Drought Tolerance, Peg
Genetic diversity of common bean (Phaseolus vulgaris L.) introduced for adaptation in Lesotho (Published)
Common beans are introduced in Lesotho from CIAT-Malawi annually to evaluate them for adaptation and other characters of economic importance. They are not being characterized for identity, therefore the study was conducted at National University of Lesotho located in the Maseru District of Lesotho with specific objectives of (1) estimating genetic distances among the common bean genotypes using morphological features and (2) identifying morphological characteristics that contributed to discrimination of these cultivars. Randomized Complete Block Design was applied with four replications. Twenty cultivars of common beans from CIAT-Malawi were used as treatments. Data were collected using descriptor of common beans compiled by International Board of Genetic Resources Unit. Data generated were subjected to cluster analysis and principal component analysis using Genstat recover (2015). Results of cluster analysis revealed four groups, of which two consisted of five cultivars, another had four and the last one only two cultivars. Besides, there were three outliers. The results of principal component analysis showed the total variation accounted for by both principal component 1 and 2 was 35.95% with each constituting 18.62 and 17.33 %, respectively. The characters responsible for variation from the first principal component analysis were seed shape, colour of flowers, colour of wings, seed-coat pattern and pod beak orientation. The characters influencing separation along the second principal component were number of locules per pod, number of seeds per pod, leaflet length, days to flowering and pod colour. It can be deduced that the cultivars broad in to Lesotho is diverse broadening the genetic base of the existing common bean genotypes
Keywords: Cluster analysis, Common bean, Lesotho, Principal Component Analysis
Variability in Yield and Yield Components among Common Bean (Phaseolus Vulgaris L.) Genotypes (Published)
Common bean is an important leguminous crop grown by farmers for home consumption and local market in Lesotho. Its low productivity has been a great concern necessitating introduction of new improved cultivars that are tested for adaptation and yield potential. The study was conducted at National University of Lesotho located in the Maseru District of Lesotho with specific objectives of (1) determining the difference in yield and yield components of common bean genotypes obtained from CIAT and also (2) determining correlation coefficient among the yield components of the genotypes. Randomized Complete Block Design was applied with four replications to lay-out an experiment. Twenty cultivars of common beans obtained from CIAT were used as treatments. Parameters measured were plant height, number of pods per plant, number of seeds per pod and weight of 100 seeds (g). Data generated were subjected to analysis of variance using Genstat recovery version (2015). The results revealed significant differences in number of pods per plant, yield and plant height among twenty cultivars. No significant difference was obtained among different bean cultivars for weight of 100 seeds per pod and number of pods per plant. Number of pod per plant showed a positive correlation between number of seed per pod, plant height and seed weight per pod but had negative correlation with weight per 100 seeds. Seed weight had negative correlation with all components of beans.
Keywords: Common bean, Lesotho, yield component