| The food security has been challenged severely with the growing population,the decreasing cultivated land,and the intensifying environmental problems all over the world.Increasing food production will be a key to solve these problems.Plant height,heading date and tillering angle are important factors affecting rice yield,so it is very meaningful to research the genes about these traits to increase grain yield.A chromosome segment substitution line?CSSL??named NY32?with the chromosome segments from NIP in the background of 93-11 was selected and a QTL?named PDT8?for plant height,heading date and tillering angle located on chromosome 8 was fine mapped.The main results are as follows:1?The CSSL line NY32 showed significant differences with plant height decreased by 26.12 cm,heading date extended by 4 days,tiller angle increased by 7.32°,panicle length shortened by 2.97 cm,1000-grain weight decreased by 3.81 g,seed setting rate decreased by about 30%,and yield per plant dropped about 21.4 g compared with 93-11.2?The QTL PDT8 for plant height was mapped to the 2.1Mb region flanked by the marker 08C061 and 08C10776 on chromosome 8 using 288 F2 individuals derived from NY32 and 93-11,Then further fine-mapped to the 70 kb region between the marker08C9322 and 08C9392 using the the recombinant plants selected from a large population with 4200 F2 individuals.3?According to the Rice Functional Genomics Annotation,there are two functional annotated genes,two expressed proteins,six transponsons and one hypothetical protein in the 70 kb region.LOCOs08g15420 encoding a cellulose-like synthase?CSLC3?is the most likely the candidate gene of PDT8 as there were several variations in the gene sequence and significant difference in the gene expression between the near-isogenic lines.The CSLC3 had higher expression level in stem,root and panicle in NIL-9311 than NIL-NIP.Meanwhile NIL-9311 had higher cellulose and hemicellulose content than NIL-NIP,but the same content in pectin and lignin. |
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