GENETIC DIVERSITY OF SIX SUGARCANE VARIETIES BASED ON SSR MARKERS

Abstract

The investigation was conducted for analysis of genetic diversity of six sugarcane varieties (Isd 16, Isd 20, Isd 28, Isd 29, Isd 30 and Isd 31) using three SSR primers (SMC119CG, SMC319CG and SMC334BS). The three SSR primer pairs amplified a total number of 34 bands from the six varieties through 8.0% polyacrylamide gel electrophoresis. The sizes of the amplified bands in the six varieties ranged from 80 to 200bp. The highest number of alleles per locus and number of genotypes per locus (1.20) was obtained from the primer SMC334BBS followed by SMC319CG (1.15) and SMC119CG (1.00) respectively. Genetic diversity or polymorphism information content (PIC) per primer pair ranged from 0.67 to 0.83 with a mean of 0.77 for all loci across the six cultivars evaluated. Both primer pairs SMC319CG and SMC334BS showed the highest and similar PIC value 0.83 followed by SMC119CG (0.67). The most polymorphic SSR marker was associated with the highest number of bands detected. The primer pairs SMC319CG and SMC334BS were the most polymorphic marker for six varieties with PIC values of 0.83. The number of varieties with unique banding patterns distinguished by the three SSR markers ranged from 66.67 to 100%. The three SSR markers were able to discriminate 88.89% of all the cultivars evaluated with unique banding patterns. The highest linkage distance was recorded between the varieties Isd 16 and Isd 20. Genetic relationships among the varieties at the average distance of 12.5 separated the variety Isd 16 from the others. Variety Isd 16 and Isd 20 were shown to be outliers and distantly related to the rest of the varieties. The three primers were able to identify and classify six sugarcane varieties indicating genetic differences among varieties with coincidence of their field performances.