The Construction Of CDNA Library From DongXiang Wild Rice And The Isolation Of Favorable Genes

Many profitable genes are contained in wild rice.Traditional hybrid methods and the cloning strategies of resistance genes commonly used are difficμlt to conduct because of reproductive isolation and poor heredity background.My project was trying to introduce cDNA of wild rice into Saccharomyces cerevisiae,and screen it with method of functional complementation of yeast mutants.My study materials is Dongxiang wild rice which originated at 28°14'N in Dongxiang County,Jiangxi Province, where is recognized to be the northernmost habitat for O.rufipogon popμlations in China, as well as in the World.It still coμld safely survive in the winter under-12.8～0℃low temperature condition,and it possesses many favourable traits such as droμght resistance, barren resistances and many favourable genes such as male sterile gene,wide compatible gene,restores gene,the disease and insect resistance gene.Total RNA was exacted from Dongxiang wild rice shoots after treatment of low ternperature.The first and second cDNA strands were synthesized by SMART method, and the double strand cDNA fragments were ligated to the YPL3 vector.The recombinant plasmids were transformed into the E.coli, a cDNA library of Dongxiang wild rice was successfμlly constructed. The resμlts revealed that the cDNA library contained 100% recombinants and the average length of inserts was about lkb.The tilter of the unamplified cDNA library was 4.4×107 cfu/ml.It indicated that this library coμld be used for yeast functional complementation screening and cloning of favorable genes within Dongxiang wild rice. Yeast host strains we used are Phosphorus Deficiency mutant MB 192 and temperature sensitive mutant Y187.