QTL Mapping For Phenotype About Growth And Development Under Brassinolides(BRs) Treatment At Seedling Stage In Rice

Rice,as one of the three major crops in the world,feeds more than half of the world’s population.In China,rice is still dominant during cultivation and promotion.Yield of rice is also closely related to national food security issues.Generally,well-developed rice lines at the seedling stage have stronger environmental adaptability,which is conducive to their promotion and planting nationwide.Therefore,cultivating strong rice seedlings has practical theoretical significance for improving the global adaptability and yield of rice.Brassinosteroids（BRs）are are indispensable endogenous phytohormones in plant.Based on the literature,BRs play an important role in rice growth and development.The results of this study on the effect of BR on the development of rice seedlings are as follows:（1）140 rice seedlings lines from the BC₄F₈RIL population constructed with Dongxiang wild rice and Shennong 265 were treated with 0.1μM BR.Then the phenotypic（plant height,root length,fresh weight and dry weight）data were counted after BR treatment.It was found that the average plant height of rice lines treated with BR decreased 0.12 cm compared with the control group;the average root length was increased 0.04 cm compared with the control group;the fresh and dry weights didn’t have significant change after BR treatment.（2）Using Ici Mapping4.2 software,QTL（Quantitative Trait Locus）mapping was performed on the above phenotypic data.One plant height-related QTL,3 root length-related QTLs,2fresh weight-related QTLs and 2 dry weight-related QTLs were mapped.Named them q SSL-9-1,q SRL-7-1,q SRL-10-1,q SRL-11-1,q SWW-2-1,q SWW-3-1,q SDW-2-1,and q SDW-6-1,respectively.Through BR treatment,targeting the QTLs which involved in the regulation of rice growth and development are significant to further explore the regulatory genes,cultivate strong rice seedlings and increase rice production.It is an important premise to ensure the country’s food security and an important strategy to respond to the country’s food security policy orientation.