EVALUATION OF GENETIC DIVERSITY OF SOME NIGERIAN ELITE AND LANDRACE UPLAND RICE CULTIVARS USING MOLECULAR AND MORPHOLOGICAL TRAITS

Abstract

The extent of genetic variability in a population is the basis of crop improvement. Two different studies were carried out on some selected Nigerian rice cultivars. In the first study, ten cultivars were characterized using morphological traits. Ten agronomic attributes were evaluated to ascertain their yield potentials. Data collected were subjected to Analysis of Variance (ANOVA) using Minitab version 17 and mean were separated using Tukey test. The genomic DNA isolation was carried out using modified cetyl trimethyl ammonium bromide (CTAB-A) method and the DNA quality was checked using Thermo Scientific NanaodropTM 1000 Spectrophotometer. Prior to DNA amplification, a PCR cocktail was prepared containing all required components. A total of 19 primers were used on the twelve chromosome of rice. The banding pattern was recorded in form of 0-1 data sheet which was analyzed using unweighted pair group method with arithmetic mean (UPGMA) based on Jacccard’s similarity coefficient. Cultivars differed significantly for some of the traits studied, which implied that the cultivars constituted a pool of germplasm with adequate genetic variability. Genotypic coefficients of variation were lower than the corresponding phenotypic coefficients in all the traits studied, indicating considerable influence of the environment on the expression of the traits. High heritability estimates were observed on 1000 grain weight (82.04), number of effective spikelet (76.16), panicle weight (72.43), number of grains (62.64) days to 50% flowering (87.73) and number of tillers (51.96). Plant height (22.77) and flag leaf length (21.23) had moderate heritability estimates. Flag leaf length (0.62), panicle length (0.39), panicle weight (0.62), number of ineffective spikelet (0.38), correlated positively with plant height (cm). The molecular characterization of 10 cultivars used for the morphological study with additional eleven cultivars comprising landraces, local selections, and improved varieties using 23 traits linked SSR primers on the 12 chromosomes of rice. DNA was extracted by