Molecular fingerprinting of locally adapted landraces and improved varieties of rice using ISSR markers
Loading...
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
DRPCAU, Pusa
Abstract
The level of genetic variability present in the population primarily depends on genetic progress. The molecular marker is a beneficial method for determining genetic variants and resolving the identities of cultivars. The goal of this research was to evaluate the diversity between 18 rice genotypes using 13 ISSR primers. Thirteen ISSR primers generated total of 81 amplified alleles with an average of 6.24 alleles per primer. Highest number of alleles i.e. 9 was obtained from the primer ISSR-834 and lowest 4 from ISSR-872 and out of 81 amplified alleles, five were rare alleles and eight were unique alleles. Amplified fragment size ranges from 148 bp to 2500 bp. Primer ISSR-880 showed very high PIC value (0.41) followed by four primers namely ISSR-872, ISSR-890, ISSR-823, ISSR-864 with high PIC values of 0.38, 0.32, 0.31, and 0.30, respectively, and rest of the primers showed medium PIC values ranging from 0.26 to 0.29. The highest value of EMR (7.11) was showed by the ISSR-834 followed by 7 in ISSR-890 and ISSR-864. The lowest value of EMR was observed in ISSR-888 and ISSR-846 with the value of 2.67 and 3.20, respectively and rest of the primers had EMR values ranging from 2.67 to 7.11. ISSR primers namely; ISSR-890, ISSR-
13
864, ISSR-834, ISSR-880 showed highest value (2.22, 2.10, 2.09 and 2.04) for marker index (MI) because these markers had higher value of either PIC or EMR or both (As MI is the product of PIC * EMR). ISSR-888 and ISSR-846 showed the lowest values (0.75 and 0.83) of MI and rest of the primers showed moderate value of MI ranging from 1.31 to 1.64. Resolving power of ISSR primers was highest in ISSR-890 (10.5) followed by ISSR-891 (9.55): ISSR-834 (8.78): and ISSR-841 (8.00). Primers with lowest RP values were ISSR-846 and ISSR-872 with RP of 2.89 and 2.44, respectively. Nei‟s Genetic Diversity (h) and Shannon Index (I) within the population of 18 genotypes yielded the value of 0.2961 and 0.4474, respectively, suggesting that the population of 18 rice genotypes is moderately diverse. Phylogenetic analysis and factorial analysis on the basis of Dice dissimilarity index grouped the 18 genotypes into 3 major cluster with cluster-I having the highest numbers of genotypes (eight genotypes) followed by cluster-II with six genotypes and cluster-III with four genotypes. The genetic Structure of 18 genotypes at K=2 (on the basis of 13 ISSR primers with 81 amplified loci) revealed that the 18 rice genotypes are the admixture of two ancestral components present in different combinations in 18 genotypes. The genetic structure explained by 81 amplified loci of 13 ISSR primers doesn‟t give the higher resolution of the actual genetic structure of 18 rice genotypes because the number of primers used is quite less and it is not known that how many chromosomes have been covered by these 81 amplified loci. However, the 13 ISSR primers used were sufficient enough to differentiate between the 18 genotypes under study with many of the primers having very high PIC, EMR, MI and RP values