Establishment and Application of Multiplex PCR System Based on Molecular Markers for Glutenin Subunit Genes (Locus) in Wheat

Wheat strong-gluten quality is closely correlated with combinations of high-molecular-weight glutenin subunits (HMW-GS) and low-molecular-weight glutenin subunits (LMW-GS). A multiplex PCR system was established to evaluate the loci for HMW-GS and LMW-GS in wheat (Triticum aetivum L.). The multiplex PCR system confered molecular markers for Ax1/Ax2*, Bx7OE, Dx5, Glu-A3d, Glu-B3i genes, and Glu-B3 locus, and proved to be effective and stable to amplify specific bands on target loci in 12 wheat cultivars with known gene/locus combinaitons. Using this multiplex PCR system, 62 major cultivars from Shaanxi Province, China were evaluated. The results showed that the frequencies were 56.5% for Ax1/Ax2*, 9.6% for Dx5, 33.9% for Glu-A3d, 1.6% for Glu-B3i, and 64.4% for Glu-B3, whereas gene Bx7OE was not detected. Most cultivars carried 2 genes (locus) with the frequency of 48.3%, followed by cultivars carrying a single gene or locus (33.9%). The frequency of cultivars carrying 3- or 4-gene (locus) combinations was 11.3%. The remaining cultivars (6.5%) were free of any elite gene (locus). Therefore, the frequency of combination of multiple strong-gluten subunit genes (locus) was low in the cultivars from Shaanxi Province, which could be improved with introduced germlasm. The multiplex PCR system developed may serve as a rapid and efficient method to select breeding materials carrying multiple genes (locus) associated with strong-gluten subunit.

摘要选用6个穗型不同的粳稻品种, 采用7个氮肥处理, 研究了精米中脂肪含量和组分对稻米直链淀粉含量和RVA特征值的影响及其对氮素的响应。结果表明, 水稻精米中脂肪含量及组分存在显著的基因型差异。小穗型品种宁粳1号、早丰9号和武育粳3号精米中粗脂肪含量和淀粉脂含量分别大于或等于与之对应的大穗型品种宁粳2号、徐稻4号和武运粳7号; 精米中非淀粉脂含量小穗型品种宁粳1号、早丰9号和武育粳3号均小于或相近于与之对应的大穗型品种宁粳2号、徐稻4号和9522。氮素对精米脂肪含量及组分的影响小于基因型, 而且对于不同的基因型水稻氮素对脂肪的调控作用不同。精米中粗脂肪含量及各脂肪组分含量与直链淀粉含量及RVA特征值关系密切。精米中粗脂肪含量与脱脂前后的崩解值呈极显著负相关, 淀粉脂含量与直链淀粉含量、脱脂前后的消减值和回复值均呈显著或极显著负相关。因此, 精米中脂肪含量, 尤其是淀粉脂含量, 对稻米的蒸煮食味品质有显著影响, 提高精米中淀粉脂含量能够提高稻米的蒸煮食味品质。