Abstract: A bacterial artificial chromosome (BAC) library was constructed for G. hirsutum acc. TM-1, a genetic and genomic standard line for Upland cotton. The library consists of 147 456 clones with an average insert size of 122.8 kb ranging from 97 to 240 kb. About 96.0% of the clones have inserts over 100 kb. Therefore, this library represents theoretically 7.4 haploid genome equivalents based on an AD genome size of 2 425 Mb. Clones were stored in 384 384-well plates and arrayed into multiplex pools for rapid and reliable library screening. BAC screening was performed by four-round PCR reactions using 23 SSR markers, three SRAP markers and one pair of primers for a gene associated with fiber development to test the quality of the library. Correspondingly, in total 92 positive BAC clones were identified with averagely four positive clones per SSR marker, ranging from one to eight hits. Additionally, since these SSR markers have been localized to chromosome 12 (A12) and 26 (D12) according to the genetic map, these BAC clones are expected to serve as seeds for the physical mapping of these two homeologous chromosomes, sequentially map-based cloning of QTLs or genes associated with important agronomic traits.

Key words: bacterial artificial chromosome library, polymerase chain reaction screening, simple sequence repeats markers, TM-1, upland cotton.