Morphological and Genetic Characterization of Pigeon Pea (Cajanus Cajan L) Using Simple Sequence Repeat Markers
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Date
2022
Authors
Katoo, Alexander Athanas
Eiiud Mwaniki Njagi
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
Pigeon pea [Cajanus cajan (L.) Millspaugh)] is a drought tolerant purse crop that is majorly cultivated for food and as a source of income. It is also used as a fodder crop in some countries. Narrow genetic variation caused by natural outcrossing and long-term artificial selection and cultivation of varieties possessing specific traits is a serious challenge in pigeon pea varietal development. Therefore, understanding the genetic diversity is a key precursor for pigeon pea genetic improvement. The objective of the present study was to establish the genetic diversity among 24 selected Kenyan pigeon pea accessions using nine agro-morphological traits and 12 SSR markers. Knowledge acquired on genetic and morphological variations as well as relationships among genotypes assist plant breeders to develop suitable breeding strategies aimed at resolving pigeon pea production constraints in Eastern and Coastal counties in Kenya. This can be done using parental lines index in the breeding programs. Planting materials (seeds) were collected from Dryland Agricultural Research Station-Katumani in Machakos. Morphological characterization was done by taking the 9 pigeon pea parameters among the 24 samples. On the other hand, for genetic characterization, DNA extraction was done using the CTAB method and the diversity done using 12 simple sequence repeat (SSR) markers. For analysis, MINITAB 17 software was used for construction of dendrogram and depicting of principal component. ANOVA results revealed a significant difference among the accessions for all 9 quantitative traits assessed. The stem diameter, number of branches per plant, 100-seed weight, which strongly associated with the first two PCs and pod length are the primary element this analysis identified. In cluster analysis, agro-morphological traits were utilized to characterize the accessions into four groups. A total of 33 alleles were observed with an average of 2.7500 alleles per marker. Polymorphic information content ranged between 0.2755 and 0.6036 with a mean of 0.4178. Pair-wise genetic dissimilarity coefficients ranged from 0.0750 to 0.9003. A neighbor-joining tree clustered the accessions into four groups. The analysis of molecular variance showed that 97% of genetic variation occurred within the populations and 3% existed among the populations. From the current study, both genetic and morphological characterization of the 24 accessions showed a significant difference among the germplasms and therefore genetic and morphological characterization clearly indicated that they are useful tools for characterization of Cajanus cajanThe results obtained from the current study provides a basis for future genetic improvement of pigeon pea
Description
A Thesis Submitted in Partial Fulfilment of the Requirements for the Award of the Degree of Master of Science (Biotechnology) in the School of Pure and Applied Sciences of Kenyatta University, November, 2022
Keywords
Morphological and Genetic Characterization of Pigeon Pea (Cajanus Cajan L) Using Simple Sequence Repeat Markers