Keywords: Saccharum , RGAP, Genetic diversity, Colletotrichum falcatum , Red rot, Resistance
Genetic diversity among 55 different sugarcane (Saccharum) cultivars varying in their response for red rot disease (Colletotrichum falcatum) was studied using Resistance Gene Analog Polymorphism (RGAP) markers. A total of 28 primers were used in the present study to screen 30 moderately resistant, five resistant, seven moderately susceptible, nine susceptible and four highly susceptible cultivars resulted in the generation of 87 distinct fragments with 91.9% polymorphism. Polymorphism Information Content (PIC) and Resolving Power (RP) were also calculated and the values were found to be 16.28 and 52.36 respectively. On analyzing the dendrogram, a clear distinctive grouping was observed between red rot resistant and red rot susceptible cultivars. This study, therefore clearly revealed that Resistant Gene Analog (RGA) markers showed greater genetic diversity and hence, constitute a rich source for analyzing the genetic diversity and phylogenetic relationships. The genotypes belonging to different clusters can be crossbreed to gain high variability of good combinations of characters.
The authors are thankful to the Head, Department of Biotechnology, Kumaun University, Nainital, India for providing lab facilities.