Genetic diversity associated with nutritive and grain quality traits using microsatellite markers in traditional land races and improved cultivars in rice (Oryza sativa L.)

Genetic diversity underlies the improvement of crops by plant breeding. Land races of rice (Oryza sativa L.) can contain some valuable alleles not common in modern germplasm. The aim here was to measure genetic diversity and its effect on nutritive and grain quality traits among rice land-race genotypes grown in Tamil nadu and Kerala. The experimental material consists of six high yielding ruling rice varieties viz., IR 72, ADT 43, ADT 45, ASD 16, TPS 4 and ADT 39 were utilized as female parent. Four nutritive and medicinal landraces in rice consumed by the people in different parts of Tamil Nadu and Kerala viz., Veeradangan, Kavuni, Kathanellu and Navara were collected and used as male parents. In molecular marker diversity analysis using SSR markers, the similarity indices for all the pair wise combinations among the 10 parents were computed. The similarity index was highest (0.93) between ADT 39 and ADT 43 along with TPS 4 and IR 72. The least similarity index (0.37) was observed between Kavuni and Veeradangan. On the basis of cluster analysis the 10 parents were grouped in to 5 clusters at 71 per cent similarity levels. Cluster 1 was constituted by Navara, Kathanellu, ADT 39 and ADT 43. Cluster 2 was constituted by IR 72, ASD 16 and TPS 4. Cluster 3, cluster 4 and cluster 5 consisted of single genotype viz., Veeradangan, ADT 45 and Kavuni respectively. It inferred that landraces have diverse genetic bases and can be utilized in future breeding programs. The results showed the potential of SSR markers for genetic diversity assessment.

• The high PIC value indicates that all these markers were highly informative and capable of distinguishing between cultivated varieties and land races.

• The SSR markers are neutral and co-dominant and could be powerful tool to assess the genetic variability among cultivated varieties and land races.

• SSR markers are more informative and can be useful for marker assisted selection for nutritive rice land races and cultivars.