Study of Segregation Distortion in Segregating Lines of Rice using Molecular Markers

Rice (Oryza sativa L.) is a vital staple crop grown across diverse regions in Asia. This study focuses on screening F2 segregating lines using molecular markers associated with amylose content. Amylose production is regulated by the Waxy (Wx) gene, which encodes Granule-Bound Starch Synthase I (GBSSI), with amylose levels directly linked to GBSSI in the endosperm. A breeding program was initiated to improve popular variety Indrayani for amylose content by crossing it with variety Bhogavati having high amylose content. The F1 progeny of the cross was confirmed with QTL-linked markers and the F1s were selfed to develop an F2 population during kharif 2022. Significant segregation distortions were observed for 8 polymorphic SSR markers, with all markers showing distortion. Three distorted markers W2R, RM 8225, and RM 340 deviated significantly towards Indrayani, while remaining five markers Wx 484, RM 3, RM 8261, RM 217, and RM 190 were deviated towards Bhogavati. The results from the molecular markers revealed that only two F2 plants, exhibited heterozygosity. These plants hold special significance and can be advanced to help identify desirable lines with improved amylose content in future generations.