Rapeseed BAC Library And Rice BAC Clone Bibac Subclone Library Construction And Related Clone Screening

This research work contains two parts.One is to construct and screen a rape BAC library.The other is to construct and screen a BIBAC subclone library of a rice BAC clone.BAC and BIBIAC clones are very important and useful for genome research.BAC clone can contain large insert and low chimeric DNA fragment,and be easily manipulated.The rape is an important crop which can bring enormous economic benefit.Plant oil which comes from rapeseed contains not only low content of saturated fatty acids but also a variety of aminoacids,vitamin which are beneficial to people's health.Thus it is deeply loved by consumers and widely cultivated in the world.In this study,we constructed a rape BAC library with rapeseed leaves provided by the institute of oil crops of Chinese academy of agricultural sciences,to clone agronomically important QTLs.There are 103,680 clones stored in 270(384-wells)plates in this BAC library.According to the genome size of rape of about 1000 M,the BAC library has approximately 12.5-fold genome coverage.The empty clone rate of the library is 2% and the average insert size is about 122.6kb.There is no organellar DNA contamination in this library.We screened the library with the linkage markers and obtained 4 positive clones which were sequenced subsequently.This work is significant for genetically improving the yield and quality of rapeseed.BAC clones cannot be directly used to transform plant.For rice transformation,we constructed a BIBAC subclone library for two rice BAC clones by Sau3 AI digestion.The library contains 768 clones with the average insert size of 18 kb.Because the target DNA size is ~200kb(two BACs),the BIBAC subclone library covers about 69-fold.We screened the library and obtained 72 positive clones verified by sequencing.These clones will be directly used in rice genetic improvement.