Distribution and Selective Effects of Vrn-A1,Vrn-B1,and Vrn-D1 Genes in Derivative Varieties from Fo

Vernalization,the process of a long exposure to low temperature to induce flowering in plants,is essential for plants to adapt to cold winters.The presence of vernalization genes Vrn-A1,-B1,and-D1 in four cornerstone breeding parents of wheat in China(Funo,Mentana,Yanda 1817,and Bima 4)and 322 derivative varieties(mostly winter wheat)from these parents were determined using PCR based molecular method.The frequencies of the VRN-1 genes in these derivative varieties were in order of Vrn-D1(67.1%)> Vrn-B1(19.6%)> Vrn-A1(5.3%),which are similar as the former conclusion that Vrn-D1 is associated with the latest heading time,Vrn-A1 the earliest,and Vrn-B1 intermediate values.The frequencies of Vrn-A1 and Vrn-B1 loci in the derivative varieties from winter wheat zones were higher than that from spring winter zones.Based on the wheat breeding history in China and the fact of non-random distribution of Vrn-A1 and Vrn-B1 in the derivative varieties from the four parents,there could be a strong selective effect on VRN-1 genes in different regions where the derivative varieties were cultivated.