QTL Mapping Analysis For Rice Drought Resistant Related Traits

This study used IAPAR-9(upland rice)/Akihikari(rice),IAPAR-9(upland rice)/Liaoyan(rice) hybrid combinations to build two F10 recombinant inbred lines (RILs) populations as the experimental material,under PEG-6000 solution simulated drought resistance condition in the germination stage.to analysis phenotypic variation which germination vigor,coleoptile length.root number,root length,height seeding,relative germination vigor,relative coleoptile length,relative root number.relative root length.relative seeding height and its drought resistance relative ratio about parents and 2 RILs populations;in Ningxia,under natural drought resistance condition in the field,to analysis phenotypic variation which leaf rolling degree,leaf drying degree,chlorophyll content.nitrogen content(total nitrogen) about parents and the RILs population.On the basis of construction of molecular linkage map using SSR markers.the analysis of QTL mapping about two populations of drought resistant traits using IciMapping 4.0 software determined preliminarily that the corresponding position of the chromosomes to control QTL traits related to drought resistance.Thus it made a foundation on drought resistance rice varieties in the field for molecular auxiliary selection breeding in the future.The main research results are as follows:1. Under drought resistance environment, phenotypic variation for drought resistance traits 2 RILs populations in drought resistance environment presented the continuous distribution of single or twin peaks.showed the number of genes that control and transgressive inheritance is obvious for QTL mapping.The capacity of upland rice IAPAR-9 as parents to adapt to drought resistance environment is stronger than Akihikari and Liaoyan 241 as rice parents; the coefficient of variation is maximum in 2 RILs populations of germination vigor and relative germination vigor,respectively germination vigor variation coefficient were 53.66% and 82.16%;variation coefficient of relative germination vigor were 54.17% and 82.41% respectively.2. The correlation analysis of drought resistance related traits showed that germination vigor,coleoptile length,root number,root length,seeding height and its drought resistance relative ratio were characterized by very significant positive correlation;respectively,root number, germination vigor and chlorophyll content and nitrogen content were characterized by very significantly negative correlation about two RILs population.3.Under PEG-6000 solution simulated drought resistance condition in the germination stage, in IAPAR-9/Akihikari RIL population,this experiment detected 2 QTLs related to germination vigor,root number.root length and seeding height.including qGVB-2 and qSH5-2 were higher on the contribution rate of the phenotypic variation at 14.98% and 15.61% respectively, as the main effect QTLs, its synergistic alleles were from upland rice parent IAPAR-9; this experiment detected 2 QTLs related to relative germination vigor,relative coleoptile length.relative seeding height including qRGV3-2 and qRSHl for the contribution rate of phenotypic variation were higher at 16.30% and 18.23% in drought resistance condition,respectively,the synergistic allelic were from rice parent Akihikari and from upland rice parent IAPAR-9.In IAPAR-9/Liaoyan 241 population,this experiment detected 5 QTLs related to germination vigor, root length and seeding height.namely qGV4、qRL3、 qSH3、qSH9 and qSH11,these 5 QTLs for the contribution rate of phenotypic variation were relative high, which the range of variation were at 10.23%～12.38% as the main effect QTL,which synergistic alleles were from upland rice parent IAPAR-9,this experiment detected QTLs were less than 10% for the contribution rate of phenotypic variation as minor QTL.4.Under drought resistance in the field,in IAPAR-9/Akihikari RIL population,this experiment detected qLRD1-1,qLRD9-2 related to leaf rolling degree and qLDD3 related to leaf drying degree had bigger contribution on the phenotypic variation,including 18.82%,13.66% and 10.73%, respectively, to give priority to effect QTLs,even synergistic alleles of qLRD9-2 and qLRD1-1 were from upland rice parent IAPAR-9,and synergistic alleles of qLDD3 was from rice parent Akihikari.In IAPAR-9/Liaoyan 241 RIL population,this experiment detected qLRD9 related to leaf rolling degree at 16.12%,mainly effect QTL,its synergistic alleles was from upland rice parent IAPAR-9.This experiment detected qCC2 related to chlorophyll content contributed variation of phenotypic variation up to 11.64%,mainly effect QTL,its synergistic alleles was from rice parent Liaoyan 241.5. This experiment detected 7 QTLs cluster distribution area which located in the 1,3,5,9 and 10 chromosomes related to germination vigor and relative germination vigor,seeding height and relative seeding height,leaf rolling degree,chlorophyll content(in the middle of leaf) and nitrogen content(in the middle of leaf) in IAPAR-9/Akihikari RIL population;this experiment detected 2 QTLs cluster distribution area which located in the 3 and 9 chromosomes related to germination vigor,seeding height and relative seeding height in IAPAR-9/Liaoyan 241 RIL population.