Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 11/1/2009
Publication Date: N/A
Citation: Interpretive Summary: Photoperiod in wheat is mainly controlled by the genes PpD-D1 previously designated (Ppd1), Ppd-B1 (Ppd2) and Ppd-A1 (Ppd3) located on long arm of chromosome 2D, short arm 2B, and long arm 2A respectively (Law et al. 1978). The dominant alleles Ppd-D1a, Ppd-B1a and Ppd-A1a confer photoperiod insensitivity, whereas the recessive alleles Ppd-D1b, Ppd-B1b and Ppd-A1b confer photoperiod sensitivity (Dyck et al. 2004). The potency of the photoperiod insensitivity was ranked in the order of allele presence Ppd-D1a followed by Ppd-B1a then with the least influence Ppd-A1a (Worland 1996). Recently, Beales et al. (2007) have characterized the molecular basis of the photoperiod response gene Ppd-D1 by isolating homologues of barley Ppd-H1 from a Chinese Spring wheat BAC library. Exploring the collinear relationship between wheat gene Ppd-D1 and barley gene Ppd-H1, a 414-bp fragment was amplified for the Ppd-D1b, whereas a 288-bp fragment was detected for the allele Ppd-D1a. SNPs in the Ppd-B1 locus were identified but the causal polymorphism as this locus was not determined. Variation at the Ppd-A1 locus is not reported in hexaploid wheat. Our objectives were to analyze the photoperiod response of a set of 73 historic and modern soft winter wheat cultivars from the Eastern United States and to determine effects of the Ppd loci in this set of cultivars.