Identification of markers for root traits using association mapping analysis in rice (Oryza sativa L.)

Abstract

Abstract Rice is mainly a semi-aquatic plant; an adequate amount of water is necessary for the better development and growth of rice crops. However, due to the scarcity of water in rice-growing countries, we faced problems like drought stress and other abiotic stresses. The research is conducted to analyze the root system and root morphology of rice plants because the rice is drought tolerant and directly correlated with the root system. The study is designed for rice root traits analysis i.e. genotypic and phenotypic. The hundred diverse genotypes of rice with three different groups viz; wild type, the cultivated type, and germplasm rice were grown under the rhizotron conditions. The 157 SSR markers were used for studying the population of rice and genotypic data were generated. The root was scanned by root scanner after 45 DAS and the parameters taken for the considerations are root length (RL), total root length (TRL), average root diameter (ARD), surface area (SA), root weight fresh (RW(F)), root weight dry (RW(D)), and root volume (RV) etc. Phenotypic data was recorded. After analysis ix markers were found associated with the root traits. Marker RM-408 on chromosome 8 is associated with the total root length (TRL) and the fresh root weight. RM-236 and RM-408 on chromosome 8 is associated with root surface area, and NOD-1 and NOD-3 on chromosome 8 is associated with the dry root weight. RM-505 on chromosome 7 is associated with the average root diameter, and RM-1 on chromosome 1 is also associated with the root surface area these markers show the marker trait associations in rice. The best genotypes found out of 100 genotypes were WR-41, RKVY-104, Bamleshwari, Nagina-22, and CT-9993 which have good root length, root volume, root diameter, etc. This study will help in future with selection and use of donor genotypes of rice for drought tolerance.