Development Of A Series Of Single Segment Substitution Lines(SSSLs) With Sequenced Varieties

Heading date,plant height and rolled-leaf are important agronomic traits.They are also quantitative traits which influenced by major and minor QTLs in same time. Single segment substitution lines which only one segment is from the donor parent eliminate the interference of the genetic background and are important experiment materials for researching QTL effects and fine mapping.In this study,combined with high-generation backcrossing and marker-assisted selecting,48 SSSLs were established in use of 9311(indica.) and Nipponbar(japonica.)as the recurrent parent and donor parents.Then,this research also detected and analyzed distribution and effects of QTL about heading date,plant height and rolled leaf.The main results are as follows:1.The polymorphic between 9311 and Nipponbare as receptor and doner were tested With 359 pairs of microsatellite marker,and 81 pairs of maker were selected for SSSL screening.The rate of polymorphic between two parents was 22.56%.2.In this study,48 SSSLs wre established after the field screening and detection of molecular marker.There were 17 SSSLs were detected in BC₂F₄-generation,24 SSSLs were detected in BC₃F₃- generation,7 SSSLs were detected in BC₄F₂-generation.48 SSSLs were located in all chromosomes besides Chr.12.3.The length of 48 SSSLs was between 3.4cM to 58.5cM,and total length of 48 SSSLs was 866.55cM and average length was 18.05cM.On average,each fragment substitution in genome-wide coverage was 1.15%.4.The rate of the candidate SSSLs genetic background similarity was between 83.8%to 98,4%in use of 47 ISSR makers to analyse the genetic background of candidate SSSLs.The results could not only show that Show the genetic background of the candidate fragments was in a high degree of consistency with the 9311,but also described the basic purpose of selection to achieved.5.10 QTLs were detected from 12 heading date SSSLs,and located on chromosome 2,4,5,7,9,11.There were 3 QTLs on Chr.4,and the number of QTLs was biggest.9 QTLs were detected from 20 plant height SSSLs,and located on chromosome 2,3,5,6,7,8,9.There were 2 QTLs on Chr.5 and Chr.6.The rolled leaf QTLs was located on Chr.5.6.According to field data and molecular marker detection,there were QTLs identification for heading date,plant height,rolled leaf:the biggest value of additive effect was 4.525,which delayed the heading date by 9 days.The minimum value of additive effect was -4.07,which advanced the heading date by 8days.The biggest value of additive effect of plant height was 24.15,which increased by 48cm.The minimum value of additive effect of plant height was -4.81,which cut by 9.6cm.The QTL of rolled leaf was qR1-5,and the degree of rolling was 38.65%.