Microsatellite marker analysis for salt tolerance in rice at early seedling stage
摘要
A set of eighteen rice varieties including two tolerant (Pokkali and CSR-36) and two susceptible (IR-29 and IR-64) checks were screened with the help of 22 SSR markers for the purpose of their molecular profiling in relation to their salinity tolerance. Altogether 190 allelic variants were detected with an average of 8.63 alleles per primer. Polymorphism information content ranged from 0.5567 (RM 292) to 0.9247 (RM 10825) with an average value of 0.7735 per primer. The primer pairs RM 10,825 and RM 220 showed the maximum number of alleles followed by primer pairs RM 10,665, RM 8094 and RM 10,748 with greater gene density and heterozygosity while the primer pair RM 10,745 showed the minimum number of alleles followed by primer pairs RM 292 and RM 10,764 with lower gene density and heterozygosity. Moreover, the primer pairs RM 292 and RM 10,745 showed the highest major alleles frequency while primer pairs RM 220 and RM 10,825 showed the lowest major alleles frequency. Using similarity coefficient in numerical taxonomic approach of classification, the 18 rice varieties were differentiated and classified into three broad groups. The first multi-genotypic group consisted of eight rice varieties, namely, Mandakini, Vaisak, Pusa Sugandh-2, Ratnagiri-4, Rajendra Dhan-102 and Sahbhagi along with two checks Pokkali and CSR-36 and can be considered as highly tolerant varieties whereas the second multi-genotypic group consisted of five rice varieties, namely, Saraswathi, Badami, Sarsa, Jyotrirmayee and MTU-7029 and can be considered as moderately tolerant varieties. The third multi-genotypic group consisted of five rice varieties, namely, Shatabdi, Daya and Golaka along with two checks IR-29 and IR-64 and can be considered as highly susceptible rice varieties. Thus, identified salt tolerant rice varieties can be used as parental donor in rice breeding programme to develop salt tolerant rice varieties.