1 Analysis of Genetic Diversity within Nepalese Maize Populations Using SSR Markers

Information on genetic diversity and relationships among breeding materials is necessary for hybrid maize breeding. Four open-pollinated varieties were analyzed using SSR markers to determine the genetic diversity within the varieties. In each variety, 15 individuals were genotyped with 30 SSR markers. Average heterozygosity percentage of the varieties was 45.07%, ranging from 35.23 % in Rampur Composite to 54.64 % in Khumal Yellow, indicating the higher level of heterozygosity in these two varieties. An average PIC value across all the polymorphic SSR loci was 0.50; which ranged from 0.47 in Manakamana-2 to 0.52 in Khumal Yellow and Arun-4. At the genotype level, the range was from 0.07 in umc1161 to 0.84 in umc1136. The total number of alleles detected was 415 for 30 SSR markers in 60 genotypes. The unique and common alleles detected respectively were 27 and 71. The average number of alleles per locus was 3.45 among the varieties, ranging from 3.21in Manakamana-2 to 3.76 in Khumal Yellow. Average gene diversity across the varieties was 0.54 and ranged from 0.51 in Manakamana-2 to 0.56 in Khumal Yellow and Arun-4. The genetic similarity coefficient of all individuals among the varieties was seen at 0.35.The MRD values were higher between Arun-4 and Manakamana-2 (0.290) and low between Khumal Yellow and Rampur Composite (0.221). Estimate of genetic distances among the varieties showed that Rampur Composite, Khumal Yellow, and Manakamana-2 were closely related sharing the similar genetic backgrounds, whereas Arun-4 was genetically more distantly related. Efforts are being made for the development and evaluation of inbred lines from these distantly related maize varieties for developing high yielding maize hybrids