Discovery, distribution and diversity of Puroindoline-D1 genes in bread wheat from five countries (Triticum aestivum L.)
- Equal contributors
1 Agronomy College, Henan Agricultural University, Zhengzhou 450002, China
2 Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Zhengzhou 450002, China
3 Collaborative Innovation Center of Henan Grain Crops, Zhengzhou 450002, China
BMC Plant Biology 2013, 13:125 doi:10.1186/1471-2229-13-125Published: 8 September 2013
Grain texture is one of the most important characteristics in bread wheat (Triticum aestivum L.). Puroindoline-D1 genes play the main role in controlling grain texture and are intimately associated with the milling and processing qualities in bread wheat.
A series of diagnostic molecular markers and dCAPS markers were used to characterize Pina-D1 and Pinb-D1 in 493 wheat cultivars from diverse geographic locations. A primer walking strategy was used to characterize PINA-null alleles at the DNA level. Results indicated that Chinese landraces encompassing 12 different Puroindoline-D1 allelic combinations showed the highest diversity, while CIMMYT wheat cultivars containing 3 different Puroindoline-D1 allelic combinations showed the lowest diversity amongst wheat cultivars from the five countries surveyed. Two novel Pina-D1 alleles, designated Pina-D1s with a 4,422-bp deletion and Pina-D1u with a 6,460-bp deletion in the Ha (Hardness) locus, were characterized at the DNA level by a primer walking strategy, and corresponding molecular markers Pina-N3 and Pina-N4 were developed for straightforward identification of the Pina-D1s and Pina-D1u alleles. Analysis of the association of Puroindoline-D1 alleles with grain texture indicated that wheat cultivars with Pina-null/Pinb-null allele, possessing an approximate 33-kb deletion in the Ha locus, have the highest SKCS hardness index amongst the different genotypes used in this study. Moreover, wheat cultivars with the PINA-null allele have significantly higher SKCS hardness index than those of Pinb-D1b and Pinb-D1p alleles.
Molecular characterization of the Puroindoline-D1 allele was investigated in bread wheat cultivars from five geographic regions, resulting in the discovery of two new alleles - Pina-D1s and Pina-D1u. Molecular markers were developed for both alleles. Analysis of the association of the Puroindoline-D1 alleles with grain texture showed that cultivars with PINA-null allele possessed relatively high SKCS hardness index. This study can provide useful information for the improvement of wheat quality, as well as give a deeper understanding of the molecular and genetic processes controlling grain texture in bread wheat.