Construction of a BAC Library Covering a Common Region between Two Sugar Beet Translocation Lines with Two Cyst Nematode Resistance Genes

Abstract

Resistance against the beet cyst nematode (BCN) has been introduced into cultivated sugar beet from wild beet by conventional breeding. The first gene effective against the BCN, Hs1pro-1, was isolated from the sugar beet translocation line A906001. It is assumed that a second nematode resistance gene, Hs1pro-1, is present in the translocation line PRO3, which does not carry Hs1pro-1 but still imparts complete resistance against the nematode and resides in the overlapping region between the two lines. The overall goal of this study was to construct a bacterial artificial chromosome (BAC) library to facilitate the cloning of Hs1pro-1. A BAC library from PRO3 was constructed containing 45,041 clones with an average insert size of 108.36 kb. Screening of the library with organelle specific probes indicated less than 1% mitochondrial and 4% chloroplast DNA content. The library covers 6.17 genome equivalents which provides a 99.76% probability of recovering any specific sequence present in the genome.