Detection And QTL Mapping Of Rice Roots Related Traits

Rice（Oryza sativa L.） is one of the main food crops in the worldand more than half of the populations all over the world take the rice as staple food. The important rice complex agronomic traits on the ground, such as production, heading stage, sterility, resistance, etc, have been the research focus and hot spots. Strong roots can help crops absorb water and nutrients.At the same time, the root system acts as a pivotalorgan for stress perception, is directly related to crops resistance.Improvenent on the resistance of rice varieties will endow rice grieat ecological adaptability and promising yield.Further Deep research onstudying of root traits genetic mechanisms of root traits, is of great significancet for rice root traits improvement.The QTLs responsible for rice root traits such as total root length, maximum root length, root surface area, root volume etc.were studied in this research using F_2:3 mapping population with 195 family lines constructed from CHA-1 and H335 using Ici Mapping V3.1 with Inclusive composite interval mapping（ICIM）.The main results are as follows:（1）1 QTL for total root length on chromosome 9 was identifiedwhose phenotypic variance contribution is 8.01%.Itsadditive effect is 137.4.It loctated in the same range asq RV9-2 and q R/S9-2.（2）2 QTLs for average root diameter on chromosome 5 and 7,respectively, were identifiedwhose phenotypic variance contribution range from9.49% to 21.12%, named q RAD5 and q RAD7, respectively.The highest one is q RAD5 whose phenotypic varianceis 21.12%.It loctated inthe same range asq RV5-1. The lowest one is q RAD7 whose phenotypic varianceis 9.49%. It loctated in the same range asq RV7.（3）1 QTL for maximum root length on chromosome 4 was identifiedwhose phenotypic variance contribution is 18.33%,named q MRL4.Its additive effectis 1.74.（4）8 QTLs for root tips on chromosome1,3,6,9 and 11 were identified,respectively,whose phenotypic variance contribution range from8.3% to 30.63%, named q RTN1-1,q RTN1-2,q RTN3,q RTN6,q RTN9-1,q RTN9-2, q RTN9-3 and q RTN11,respectively,the highest one is on chromosome 1 whose phenotypic varianceis30.63%. Its additive effectis 30.68.（5）5 QTLsfor root volume on chromosome 5, 7 and 9,respectively,were identifiedwhose phenotypic variance contribution range from 9.5% to 18.4%, named q RV5-1, q RV5-2, q RV7, q RV9-1 and q RV9-2,respectively,the highest one is on chromosome 9 which explained 18.4% of the phenotypic variance.Its additive effectis 3.08.（6）6 QTLs for root dry weight on chromosome 1, 3, 8, 9, 11 and 12,respectively,were identifiedwhose phenotypic variance contribution range from 8.89% to 20.59%, named q RDW1, q RDW3, q RDW8, q RDW9, q RDW11 and q RDW12,respectively,the highest one is on chromosome 12 which explained 20.59% of the phenotypic variance.Its additive effectis 0.106.（7）6 QTLs for R/S on chromosome 3,6, 8, 9 and 12,respectively,were identifiedwhose phenotypic variance contribution range from 8.02% to 16.35%, named q R/S3, q R/S6, q R/S8, q R/S9-1, q R/S9-2 and q R/S12,respectively,the highest one is q R/S12 which explained 16.35% of the phenotypic variance. Its additive effectis 0.08.