Abstract:

Growth and development habit (spring vs. winter) of wheat (Triticum aestivum L.) is determined by Vrn genes, which affect its adaptability. The two-step procedure required for the CAPS marker and the additional cost of restriction enzyme were the limitation in high throughput screenings in breeding programs, so it was hoped that the CAPS marker could be replaced by the STS marker. The STS marker and CAPS marker of Vrn-A1 gene were compared by testing 22 Chinese wheat cultivars, and then 250 Chinese wheat cultivars were used to detect the Vrn-A1 gene distribution. The testing results of STS marker for Vrn-A1 gene in the 22 Chinese wheat cultivars were completely consistent with those of CAPS marker, suggesting that the STS marker is efficient and reliable for identifying Vrn-A1 gene in wheat breeding program. The average frequency of Vrn-A1 gene was 36.8% in the 250 tested Chinese wheat cultivars. Frequencies of Vrn-A1 gene in Northern Winter Wheat Region, Yellow & Huai River Facultative Winter Wheat Region, Middle & Low Yangtze Valley Winter Wheat Region, Southwestern Winter Wheat Region, Northeastern Spring Wheat Region, Northern Spring Wheat Region, Northwestern Spring Wheat Region and Xinjiang Winter-Spring Wheat Region were 3.0%, 19.8%, 17.4%, 35.3%, 100%, 100%, 100% and 42.9%, respectively. The differences of Vrn-A1 gene frequency were highly related to the growth habit of wheat. Middle & Low Yangtze Valley Winter Wheat Region and Southwestern Winter Wheat Region had a decreased frequency of Vrn-A1 gene, which increased from 1950s to 1970s, and then decreased since 1980 in Yellow & Huai River Facultative Winter Wheat Region. Frequency of Vrn-A1 gene was 27.6% in 58 cultivars whose planted area was more than 670,000 ha annually, and 70% in 10 cultivars with largest grown area in China from 1949 to 2000. The information could be useful for improving adaptability and yield potential of Chinese wheat cultivars.

Key words: Triticum aestivum L., Vernalization gene, Vrn-A1, Molecular marker