Distribution of the Vrn-D1b allele associated with facultative growth habit in Chinese wheat accessions

Abstract

Vernalization requirement in wheat is determined by allelic variation mainly at three loci, Vrn-A1, Vrn-B1 and Vrn-D1. Up to 2011 only two alleles at the Vrn-D1 locus were known. The dominant allele, now designated as Vrn-D1a, confers spring growth habit, and the other, recessive allele, vrn-D1, is associated with the winter growth habit. Recently, we found an additional dominant allele, Vrn-D1b, associated with the facultative growth habit. As facultative wheat cultivars play an important role in wheat production we screened 689 accessions from all over China, with a specific aim of determining the frequency and distribution of Vrn-D1b. The results showed that Vrn-D1a, Vrn-D1b and vrn-D1 were present in 27.3, 20.6 and 52.1 % of all accessions, respectively. Vrn-D1a was mostly distributed in the autumn sown spring wheat zone, whereas Vrn-D1b was common in the autumn sown facultative wheat zone. One cultivar (Shiluan 02-1) was heterogeneous at the Vrn-D1 locus. A comparison between the Vrn-D1b genotype and the vrn-D1 genotype from the same cultivar showed that without vernalization the Vrn-D1b genotype reached the double ridge (DR) stage 27 days earlier than the vrn-D1 genotype. Vernalization responses, expressed as a reduction in the number of days to reach the DR stage following cold treatment, at 4°C for 20, 30 and 40 days, were 62, 67 and 75 days, respectively, for the Vrn-D1b genotype, and 74, 87 and 98 days, respectively, for the vrn-D1 genotype, confirming the effect of Vrn-D1b on facultative growth habit. Pedigree analysis indicates that the Vrn-D1b allele originated from Chinese landraces.

Trait Phenotyping and Genic/Random SSR Markers Characterization for Breeding Early Maturing Wheat’s for Western-Himalayas

“…RNase treatment and phenol: chloroform: isoamyl alcohol precipitation was carried out for puri cation of isolated DNA (Sambrook et al 1989). The basic PCR ampli cations were performed in a 20 µL reaction mixture containing 10 µL 2 x Taq PCR Master Mix, 1 µL 50-100 ng µL -1 g DNA, 1 µL 10 p mol lL -1 of each primer and 7 µL sterilized ddH 2 O (Guo et al 2015). The PCR pro le was: Initial denaturation at 94°C for 5 minute, followed by denaturing at 94°C for 1 minute, annealing at 52-60°C for 30s, and extension at 72°C for 30 seconds to 2 minutes, and steps 2-4 were repeated 34 cycles with a nal extension at 72°C for 10 min.…”

Association of the Recessive Allele vrn-D1 With Winter Frost Tolerance in Bread Wheat

“…For each treatment, three plants from each genotype were sampled for observing the developmental morphology of inflorescence using a stereoscopic microscope (Olympus, Tokyo, Japan). Days from sowing to the double ridge stage were used to measure the response to vernalization as described by Guo et al (2015) .…”

Allelic diversity of the <i>Vrn</i> genes and the control of growth habit and earliness in wheat

“…The results showed that allele Vrn-D1a, Vrn-D1b and vrn-D1 were present in 27.3, 20.6 and 52.1 % of the specimens, respectively. Pedigree analysis indicates that Vrn-D1b originated from Chinese landraces (Guo et al, 2015).…”