Genetic diversity among muskmelon (Cucumis melo L.) germplasm in Bangladesh as revealed by microsatellite markers

摘要

Information about genetic variation has become more critical and deciding factor for any breeding and improvement effort,is difficult inefficient and inaccurate when based on morphological traits only. Therefore, this investigation was conducted using nine microsatellite DNA markers to evaluate genetic variation among 96 muskmelon germplasm in Bangladesh. All nine microsatellite markers were polymorphic. Lower values detected in observed than expected heterozygosity for all loci, indicating homozygous condition in the sample population. A total number of 28 alleles were generated by the nine primers across 96 germplasm. The locus TJ10 showed the highest number of alleles (5), whereas CMGA104, CMCT44, CMAG59, CMTA134a and J27 were generated lowest (3) number of alleles.Allele size ranged between 98 bp (CMCT44) to 198 (CMCTT144). The Polymorphism Information Content (PIC) valuesranged from 0.117 to 0.770for the locus CMCTN86and TJ10, repectively. Values of genetic differentiation (Fst) and gene flow (Nm) ranged from 0.535 to 1.000 with an average of 0.776 and from 0.000 to 0.218 with a mean value of 0.072, respectively. Broad genetic base was found among the muskmelon germplasm used in this study. The average pair-wise Nei’s genetic distance value was 0.605. The highest genetic dissimilarity coefficient (GD=2.300) was between the germplasm AHM-241 and IAH-102, whereas germplasm IAH-251 and IAH-259 comprised lowest genetic diversity (GD =0.000). In the UPGMA dendrogram, among 96 germplasm of muskmelon 84 grouped in cluster “I” and other 12 in cluster “II”.Keywords: Muskmelon, Microsatellite (SSR) marker, Polymorphism, Genetic diversity, Germplasm.