Diversity, characterization and evaluation in Pummelo (Citrus maxima Merr.) cultivars using SSR markers and quality parameters

Abstract

Fourteen pummelo (Citrus maxima Merr.) fruit varieties were evaluated through morphological and molecular methods to determine the genetic diversity among them. The analysis showed that maximum contribution (60%) towards diversity was due to the number of fruits per tree and rag percentage. Principal component analysis explained 80.26% of the total observed variability. Molecular characterization of pummelo varieties using 60 SSR markers revealed 26 polymorphic SSR loci having 77 amplified alleles and the number of alleles ranged from 1 to 4 with an average of 2.96 alleles per locus. The highest number of alleles per locus recorded was four as amplified by the SSR markers, CAT01, CS05, CCSM70, CIBE5156, AG14, CIBE4728 and CMS26. The PIC value ranged from 0.12 (CIBE5720) to 0.73 (CAT01) with average value of 0.53. Maximum heterozygosity was found in CAT01 (0.73) followed by CS05 (0.72) and AG14 (0.69). Pink Pummelo and White Pummelo showed the highest genetic similarity having coefficient of 89% and were closely related. The present study indicated low genetic diversity in pummelo varieties despite having high morphological variability, which could be elucidated by the fact that much of the phenotypic variation witnessed may be due to somatic mutations.