ibclogo XVI International Botanical Congess

Abstract Number: 5129
Poster No. = 1852


RELATIONSHIP BETWEEN A SUBGENOMIC-SPECIFIC CENTROMEREASSOCIATED REPEATED DNA OF SORGHUM AND SUGARCANE


H. J. Price, M. Zwick , M. N. Islam-Faridi, G. L. Hodnett, H. Zhang, J.-S. Kim, and D. M. Stelly. Texas A&M University, College Station, Texas 77843 USA


FISH of pCEN38, a 1047 bp cloned sorghum repetitive DNA, yielded differentially strong signals around centromeres of 10 chromosomes of S. bicolor (2n = 20). Meiotic metaphase FISH localized pCEN38 to active centromeric regions. Pachytene FISH revealed a trimodal distribution of signal flanking centromeric regions. Clone pCEN38 has homology (62-86%) to the SCEN family of sugarcane. FISH of pCEN38 to sugarcane chromosomes revealed signal strength from extensive to none around the primary constrictions. We infer that a species with n = 5 chromosomes carrying the repeat contributed a sub-genome in the origin of n = 10 sorghum and subgenomes in the origin of sugarcane. The base chromosome number for both genera may be five. Currently proposed graminous genome relationships may need reconsideration. Research supported by the Texas Agric. Exp. Station and a Texas Advanced Technology and Research Program Grant 999902090 (HJP and DMS).

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