The Diversity of Viviparous-1 Gene
Exploiting the diversity of Viviparous-1 gene associated with pre-harvest sprouting tolerance in European wheat varieties
L. Q. Xia1,2, M. W. Ganal3, P. R Shewry4, Z. H. He1, Y. Yang1, M. S. Röder2
1 Institute of Crop Science/National Wheat Improvement Center/The National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences (CAAS), No 12 Zhongguancun South Street, Beijing 100081, China
2 Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany
3 TraitGenetics GmbH, Am Schwabeplan 1b, 06466 Gatersleben, Germany
4 Crop Performance Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
Pre-harvest sprouting (PHS) reduces the quality of wheat (Triticum aestivum L.) and the economic value of the grain. The objective of this study was to evaluate the diversity of the Viviparous-1B (Vp-1B) gene associated with PHS tolerance in a collection of 490 widely grown winter wheat varieties from central and northern Europe. Our previous studies identified three Vp-1B alleles, Vp-1Ba, Vp-1Bb and Vp-1Bc, in wheat cultivars with distinct PHS tolerance and ABA responsiveness, and each of them could produce a set of transcripts, only one of which was correctly spliced and had the capacity to encode the full length VP1 protein and highly expressed with Vp-1Bb and Vp-1Bc than with Vp-1Ba. Furthermore, genotypes with different levels of tolerance to PHS showed different responsiveness to ABA exposure and differences in transcript levels of Vp-1Ba, Vp-1Bb and Vp-1Bc were observed after ABA treatment (Yang et al. 2007a). Based on this, a Vp1 STS marker Vp1B3 was developed and validated among a set of Chinese wheat germplasm, and the results suggested that there was a strong association between the polymorphic fragments of Vp1B3 and PHS tolerance, and it could be used as an efficient and reliable co-dominant marker in the evaluation of wheat germplasm for PHS tolerance and marker-assisted breeding for PHS tolerant cultivars (Yang et al. 2007b).
In this study, we determined the diversity of Vp-1B alleles in 490 accessions of European winter wheat varieties by using the developed STS marker Vp1B3 in order to provide basic information for the breeder for the production of improved PHS tolerant varieties. Four alleles of Vp-1B were found in the wheat varieties tested, three of which (Vp-1Ba, Vp-1Bb and Vp-1Bc) had previously been identified in Chinese wheat varieties. The fourth was a new allele which had a 25-bp deletion in the third intron region compared with the nucleotide sequence of Vp-1Ba, and was designated as Vp-1Bd (Xia et al., submitted).