Molecular Analysis For Salt Tolerance QTLs Emphasizing Saltol QTL in Some Egyptian and International Rice Genotypes (Oryza sativa L.)

Document Type : Original Article

Authors

1 Rice Research and Training Center, Field Crops Research Institute, Agricultural Research Center, Sakha 33717, Kafrelsheikh, Egypt.

2 Rice Research and Training Center, Field Crops Research Institute, Agricultural Research Center, Sakha 33717, Kafrelsheikh, Egypt

Abstract

Rice (Oryza sativa, L.) is one of the strategic crops in Egypt, and the improvement of its productivity is an essential requirement to ensure food security. Salinity is one of the major environmental stresses that limit the productivity of rice crop. 14 SSR markers linked to salinity were used to study the genetic diversity within salinity tolerance QTLs in 18 rice genotypes. All the utilized primers were polymorphic, the number of alleles ranged from 2 to 6 with an average of 3.42 per locus. The major frequency alleles ranged from 0.33 to 0.78 for RM562 and RM412, respectively.The PIC values varied from 0.79 to 0.37 with an average of 0.50. Seven SSR markers i.e. RM562, RM493, RM1287, RM223, RM242, RM10720, and RM5 were informative markers with PIC values more than 50%. Jaccard's similarity coefficients ranged from 0.07 to 0.93 with an average of 0.45.The studied genotypes were grouped into two major clusters at 0.18 similarity. The PCA analysis had the ability to classify the studied genotypes into clearly four separate clusters based on the origin and salinity tolerance.13 haplotypes other than the reference haplotype were identified. The number of genotypes per haplotype ranged from one to five. The current investigation highlighted the high amount of genetic diversity among the studied genotypes. Egyptian Yasmine, the fragrant genotype, was the most promising genotype where it has 50% of Pokkali alleles at Saltol QTL region and this makes it suitable to be used as salt tolerance donor for MAS in salinity tolerance molecular breeding program. 

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