Development Of Chromosome Segment Substitution Lines And QTL Mapping Of Seed Storability In Rice(Oryza Sativa L.)

Rice is the main food crop in China.Rice seed storage is a strategic need for agricultural production.Prolonged storage of seeds often results in decrease in vigor.The storability of seeds is a complex genetic trait.Chromosome Segment Substitution Lines(CSSLs)are the optimal population for studying the inheritance of complex traits.In this study,two sets of CSSLs were developed with Xiushui 134 and Yangdao 6 as reciprocal recurrent parent.The CSSLs of Xiushui 134 as the recurrent parent were used to detect Quantitative Trait Locus(QTLs)for total dissolved solids(TDS)of seed and germination rate(GR),germination potential(GP),germination index(GI),mean germination time(MGT).The main results are as follow:The CSSL of Xiushui134 as the recurrent parent contained 53 individuals whose length of donor segments ranged from 7.4 to 182.15 cM.It accounted averagely for 5.0%(from 0.49% to 12.15%)of whole rice genome.The total length of target donor segments including 12 chromosomes was 1995 c M,which was 1.33 times as long as whole rice genome.The CSSL of Yangdao 6 as the recurrent parent contained 46 individuals whose length of donor segments range from 11.3 to 243.6 cM.It accounted averagely for 5.5%(from 0.78% to 16.8%)of whole rice genome.The total length of target donor segments including 12 chromosomes was 1956.8 cM,which was 1.3 times as long as whole rice genome.After aging treatment,total dissolved solids,germination rate,germination index,germination potential of aged seed all decreased,while the mean germination time of aged seed increased.The total dissolved solids of aged and non-aged seed both were positively correlated with the average germination time while negatively correlated with the germination rate,germination index and germination potential;the germination rate,germination potential and germination index were positively correlated with each other.Under the non-ageing treatment,a total of 30 QTLs related to the total dissolved solids,germination momentum,germination index,germination potential,mean germination time were detected.Among them,qTDS1-1-3 was the major QTL that controlled total dissolved solids with a relative effect of 22.7% and explained phenotypic variations of 8.9%;qGP1-9-1 was the major QTL controlling germination rate with a relative effect of 5.2% and explained phenotypic variations of 6.6%;qGM1-9-1 was the major QTL for germination potential with a relative effect of 7.8% and explained phenotypic variations of 7.6%;qMGT1-2-3 was the major QTL for mean germination time with a relative effect of 11.2% and explained phenotypic variations of 13.6%;q GI1-9-1 was the major QTL for germination index with a relative effect of 10.1% and explained phenotypic variations of 5.8%.Under the ageing treatment,a total of 9 QTLs for the total dissolved solids and mean germination time were detected.Among them,qTDS2-1-2 was the major QTL that controlled total dissolved solids with a relative effect of 24.2% and explained phenotypic variations of 19.3%;qMGT2-5-1 was the major QTL for mean germination time with a relative effect of-23.1% and explained phenotypic variations of 6.4%.Under the ageing and non-ageing treatment,6 QTLs for total dissolved solids were detected on the locus of S1-505,RM8105 and RM259 on chromosome 1,RM5545 on chromosome 8,RM5535 and RM6797 on chromosome 9.