Tag Archives: Cluster analysis

Genetic Diversity of Maize (Zea Mays L.) Grown in Lesotho Using Morphological Makers (Published)

A large collection of maize germplasm is introduced annually to Lesotho from CYMMIT in Zimbabwe for evaluation of adaptability and yield performance. This collection is not characterized for degree of similarities and dissimilarities using morphological and other markers. The study was conducted with the objectives of (a) estimating genetic distance among maize cultivars using cluster analysis and (b) identifying morphological characters with high discriminatory power to segregate maize cultivars. The study was conducted at National University of Lesotho, Experimental farm. Randomized Complete Block Design was applied with ten treatments and three replications.  Data collected using Descriptor compiled by International Board of Plant Genetic Resource Unit included number of leaves per plant, tassel colour, number of cobs, silk colour, stem colour, plant height, number of ears, ear length, cob diameter, number of kernels, kernel arrangement, kernel colour, shape of upper surface, kernel type, leaf length and tassel length. Data were subjected to GENSTAT software package to generate cluster analysis and perform principal component analysis. The results of cluster analysis revealed two big groups, of which one consisted of six cultivars and another consisted of four cultivars. Besides, there was one outlier. Two big groups were further divided into sub-groups, Three principal component analyses were used to analyze the results, which constituted 65.37% of the total variation. The first one showed variation of 26.93%, the second one showed 20.65% while the third one had 17.79%. The first principal component was constituted by ear length, tillering, maize height, total number of kernels, cross-section of cob and stem colour. The characters comprising second principal component were kernel type, kernel row arrangement, silk colour, number of ear and number of kernel row. Lastly, the character influencing separations along third principal component were number of kernel row, silk colour and number of leaves. The study was able to distinguish the cultivars.

 

Keywords: Cluster analysis, Lesotho, Maize, Principal Component Analysis

Characterisation of Wheat (Triticum Aestivum L.) Cultivars Grown In Lesotho by Morphological Markers (Published)

Wheat is one of the major cereal crops grown in Lesotho, ranking third after maize and sorghum. Cultivars of wheat are imported from South Africa without characterization.  The study was therefore conducted with the following objectives; (1) to distinguish wheat cultivars grown by farmers, (2) to estimate genetic distance among wheat cultivars and (3) to identify the characters that have high discriminatory power. Complete Randomized Block Design with ten treatments and three replications were applied. Data were collected using Descriptor and analysed using GENSTAT software to perform cluster and principal component analysis. The first three principal components constituted 84.572% of the total variation. First principal component variation accounted for 55.738%, while second principal component contributed 15.737% and third principal component constituted 12.858%. Characters responsible for variation in the first component were spikelets, spike height and tillers. Separation among second component was brought about by plant height, reproductive tillers and seeds per spike. Variation in component three was due to glume hairiness, seed size and plant height. Cluster analysis formed two groups, A and B, and one outlier. Group A comprised of Gariep, Koonap, Elands and Senqu while Group B consisted SST374, SST356, PAN3195, PAN3379 and TugelaDN. Group C was an outlier containing Matlabas. The findings showed that the cultivars were different from each other and as such genetic variation exists that broaden the spectrum of germplasm, from which farmers can make a wider choice.

Keywords: Cluster analysis, Lesotho, Principal Component Analysis, Wheat, morphological characters

Effects of Group Communication Cohesion of Staff and Cluster Analysis in a Multi Campus University (Published)

To improve on group cohesion in organisations, effective communication should help contribute to the overall job performance and the goals set. This study therefore examined the effects of group communication cohesion of staff and cluster analysis applications in attempt to impact on staff pattern of behaviour at work. A survey design was adopted in a population of 1,739 with a sample size of 304 respondents compised of management members, senior members, senior staff and junior staff from all the four campuses of the University. The analysis of the survey instrument reliability resulted in a Cronbach Alpha value of 0.83. The two-step cluster analysis was used to also analyse group communication cohesion among respondents and to identify the natural group; which revealed four groups of employee cohesion patterns. Clusters I and II showed high cohesion while clusters III and IV showed low cohesion. This shows that employee rank influences the grouping patterns and membership of a cluster (group) and was also influenced by the campus of the employee, as revealed from the chi-square analysis.  Further analysis identified tactical group, operational group, strategic group and contingency group which represent four employee cohesion patterns, to match the status of staff in the university. To enhance group communication cohesion, it is recommended that the University authority should promote the use of information flow, feedback, good working relationships between superiors and subordinates; and the use of circulars, letters, notices, newsletters, should be greatly enhanced. The results again pointed out the influence of ethno-linguistic use at work place, salary discrimination, lack of capacity and little cooperation of management. The use of durbars and other social events periodically to bring staff together, create awareness and foster stronger cooperation should be promoted were recommended. The study result could guide policy formulation and contribute to knowledge in development communication in the University

Keywords: Cluster analysis, Group Communication Cohesion, Multi Campus University, University Staff

Screening Of Maize Cultivars Grown In Lesotho for Drought Tolerance -2 (Published)

Drought is increasingly becoming a common natural phenomenon that adversely affects maize productivity in Lesotho necessitating mitigation strategies. Irrigation may be a viable option but water is becoming scarce, hence choice of drought tolerant cultivars maybe the best alternative. The study was conducted in Lesotho with the aim of (1) verifying the differences among maize cultivars in response to induced water deficit stress, (2) evaluating maize cultivars against different concentration levels of Polyethylene glycol which induces drought stress in germinating seed and seedling growth and (3) identifying cultivars of maize tolerant to drought stress. Complete Randomized Design with three replications and 22 treatments were employed in the laboratory experiment. Twenty-two different accessions of maize were collected from Department of Agricultural Research in Maseru, Lesotho, were evaluated for their genetic potential to drought tolerance at seedling stage. Water stress was induced by non-ionic water soluble polymer polyethylene glycol (PEG) of molecular weight 6000 using the procedure which was described by Michel and Kaufiman (1973). After ten days, data were collected on plumule length, radicle length, coleoptile length, radicle fresh weight, plumule fresh weight, coleoptile fresh weight, radicle dry weight, plumule dry weight and coleoptile dry weight. Analysis of variance was performed using Genstat recovery Version 14 to establish the difference among treatments. The results showed significant differences (P<0.05 and P<0.01) among the accessions, PEG-6000 concentrations and their interactions for evaluated seedling traits suggesting a great amount of variability for drought tolerance in maize cultivars. It was further revealed that as concentration of PEG is increased, values of the parameters measured decreased. The maize cultivars which outperformed the others in terms of drought tolerance were CAP 9019, SNK 2778, DKC 78-27, PAN3MO1 and Natal.

Keywords: Cluster analysis, Drought Tolerance, Maize, Peg

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