Construction And Characterization Of A Large Insert Deep Coverage BIBAC Library Of Sorghum Nengsi-1

Binary bacterial artificial chromosome (BIBAC) could replicate in both E. coli and Agrobacterium. Moreover, it could carry large insert size DNA fragments and transfer them into plants. It provides a powerful tool for map-based cloning, functional analysis etc. Nowadays, this technology has been widely applied.Constructing a large insert and deep coverage BIB AC library for Sorghum Nengsi-1can genetically improve plants with beneficial traits that only sweet sorghum contains. Rice is the most important commercial crop, and it is of great significance to conduct genetic transformation in rice. In this syudy, a BIB AC library for sorghum Nengsi-1was constructed and characterized. Sampling BIBACs were end-sequenced and tested for stabilities in E.coli and Agrobacterium.The BIB AC library contains51,840clones with an average insert size of110.7kb, which represent almost7.7-fold of Sorghum genome (750Mb). The empty vector rate is only2.29%, the contaminations of chloroplast and mitochondria are0.1%and2.2%, respectively.One hundred forty four BIBAC clones were sequenced and252end sequences were obtained with an average sequence length of579.0bp and a success rate of up to87.5%. The total length of the sequenced ends is14,5913bp which accounds for0.02%o of Sorghum’s genome size. Preliminary analysis of the BIBAC end sequences showed that most of the repeat sequences are retroelements, which account for46.59%of the total sequence length. Sixty six BIBAC clones were anchored on the sorghum reference sequence.Stability test of BIBAC clones showed that all the BIBAC clones are stable after cultivation for different times in E. coli and90%BIBAC clones are stable in Agrobacterium. However, one clone was not stable in Agrobacterium, possibly occurred during Agrobacterium-transformation.