Morphological, molecular and quality characterization of rice varieties and landraces from Eastern and Southern Africa

Masters Thesis

This study was carried out to evaluate the genetic diversity of rice germplasms collected from Eastern and Southern Africa countries (Burundi, Kenya, Malawi, Tanzania including Zanzibar and Rwanda) based on morphological, molecular and quality traits for utilization in breeding programmes. A total of 191 rice germplasms were characterized in this study. Twenty four qualitative and quantitative morphological traits, eight grain quality traits and 18 Simple Sequence Repeat (SSR) markers were used for analysis. The plant morphological traits viz., basal leaf sheath color, leaf blade color, panicle exsertion, panicle type, apiculus color, lemma/palea color, awning, number of days to 50% flowering, days to maturity, leaf length and width, panicle length, plant height, spikelet fertility showed most variation among the genotypes. Among the grain quality traits, milling recovery, degree of milling, 1000-grain weight, brown rice length and shape exhibited most variation among the evaluated genotypes. Genetic variation analysis of morphological and grain quality traits resulted in grouping of the germplasms into seven clusters. Principal component analysis showed that 75.37% of the variability was contributed by the first six principal components. A total of 18 SSR’s markers were used and 16 found to be polymorphic. A total of 121 alleles were obtained on polymorphic SSR with an average of 7.56 allele per marker and the number of alleles ranged from 2 to 20. The Polymorphism Information Content (PIC) values ranged from 0.01 to 0.89 with an average value of 0.49. The genetic diversity of each SSR locus appeared to be associated with number of allele detected per locus. The cluster analysis based on similarity index of simple matching grouped the studied rice genotypes into six clusters. The information obtained will be very useful in identification and selection of suitable parents for use in breeding programmes to develop unique germplasms that complement existing varieties.

International Rice Research Institute (IRRI)