Multi-trait mapping of QTLs for drought tolerance indices in rice

Rahimi, Mehdi; Dehghani, Hamid; Rabiei, Babak; Tarang, Alireza

Multi-trait mapping of QTLs for drought tolerance indices in rice

Document Type : Research Paper

Authors

¹ Ph. D. Student, Dept. of Plant Breeding, Tarbiat Modarres University

² Assoc. Prof., Dept. of Plant Breeding, Tarbiat Modarres University

³ Assoc. Prof., Dept. of Agronomy and Plant Breeding, University of Guilan

⁴ Assist. Prof., Agricultural Biotechnology Research Institute of North of Iran

Abstract

Rice improvement for drought tolerance requires reliable assessment of diversity and genetic analysis of drought tolerance related indices in breeding populations. In this study, 150 F₅ families derived from a cross between Sepidroud (Indica) and Gharib (Indica) varieties were evaluated to multi-trait mapping of genomic regions controlling drought tolerance indices in normal and drought stress conditions. Results of biplot analysis showed that stress tolerance index (STI), mean productivity (MP), geometric mean productivity (GMP) and harmonic mean (HM) are suitable indices to select the high-yielding genotypes in applied rice breeding programs. QTLs mapping for each index using composite interval mapping identified three, three, two and three QTLs for HM, MP, GMP and STI, respectively, but the joint-analysis data for investigate the genetic relationships between these indices using the multi-trait mapping showed that there are significant genetic relationships between studied indices, so none of these identified QTLs didn’t independently control an index and jointly controlled multiple indices. Results from current study showed that the multi-trait joint analysis not only identified additional QTLs, but also revealed the genetic relationship between different highly correlated traits at the molecular level.

Keywords