Importing Yield-Enhancing QTLs From Wild Rice, Oryza Rufipogon And Pyramiding Elite Genes By Molecular-Marker-Assisted Selection

Molecular-marker-assisted selection(MAS) is one of the most popular methods in modern breeding process,which this technology can transmit and pyramid several genes to come to improve crops by using molecular-marker identification and selection accompany with the procedure of field hybrid or backcrossing.The purpose of present research is that:1) imported yield enhancing QTLs derived from Malaysia O.rufipogon to Huahui 4 and Hua190,the two cultivate varieties of rice,to construct near-isogenic lines (NILs) through MAS,then examed whether these QTLs can take the yield enhancing effect by hybriding with male sterile lines;2) pyramided Xa23 and GS3,the two genes,to Zhenshan97B and II-32B while using MAS with a view to improve its quality and resistance.The excellent male sterile lines been improved can provide some wonderful resources for rice breed.The main results showed as follows:1.Three yield enhancing QTLs,qtl1.1,qtl2.1 and qtl9.1,were imported from Malaysia O.rufipogon to a rice cultivate variety named Huahui 4,and two yield enhancing QTLs,qtl3.1and qtl9.1,were imported from the same donor parent line to another variety named Hua190,and for the sum to construct 5 NILs.2.Combinated the Huahui 4 and Hua190 which these imported loci were heterozygous to Jufeng A and Peiai 64S,two male sterile lines,for each.Then analysed yield enhancing effect of these QTLs.The results showed that at the background of Huahui 4,qtl2.1 performed significant decreasing effects to receptor parent lines in Number of spikelets per panicle,grains per panicle and yield per plant of these three traits, with contradict of qtl9.1,which this QTL can increase panicle length significantly.And as for the background of Hua190,the QTL of qtl3.1 can increase the trait of effective tillers significantly and qtl9.1 can increase the trait of panicle length significantly.3.Pyramided Xa23 and GS3,the two genes,to Zhenshan97B andâ…¡-32B while using MAS.Improved varieties of Zhenshan97B andâ…¡-32B performed apparent resistance to bacterial leaf blight,and at the same time grains of these new two varieties were longer than their original parent lines...