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

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.

Genetic Mapping to Detect Stringent QTLs Using 1k-RiCA SNP Genotyping Platform from the New Landrace Associated with Salt Tolerance at the Seedling Stage in Rice

“…The QTLs detected in this experiment were compared to those previously recognized in various studies. In the vegetative stage, a major salt-tolerant QTL was identified as Saltol QTL, which was mapped in chromosome 1 and had a strong phenotypic effect (R 2 of 39% to 44%) from the landrace Pokkali [ 19 , 67 , 68 , 69 , 70 ]. Another major salt-tolerant gene is SKC1, also identified in chromosome 1 during the vegetative stage from the Nona Bokra [ 8 , 71 , 72 , 73 ].…”

Combining Ability and Heterosis Studying for Yield and its Attributes of Hybrid Rice Under Normal and Salinity Conditions Using Line × tester Scheme

“…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 crops (Ramadan et al, 2020). Rice is the most important crop, being the dominant food in most of the countries around the world.…”