不同土壤条件下山农12小麦籽粒HMW-GS积累及GMP粒度分布特征

HMW-GS Accumulation and GMP Size Distribution in Grains of Shannong 12 Grown in Different Soil Conditions

在沙壤、中壤和黏壤3种质地土壤条件下,以优质强筋小麦品种山农12为材料研究了小麦强势与弱势籽粒高分子量谷蛋白亚基(HMW-GS)积累特征及其与谷蛋白大聚合体(GMP)粒度分布的关系。结果表明,3种质地土壤上,小麦强、弱势籽粒HMW-GS花后14d均已形成,强势粒HMW-GS含量明显高于弱势粒,说明强势粒具有较强的HMW-GS积累能力。小麦籽粒HMW-GS含量和GMP含量均表现为黏壤土>中壤土>沙壤土,说明黏壤土有利于HMW-GS的积累。小麦GMP粒径分布范围在0.37～245μm之间;数目分布呈单峰曲线,体积和表面积分布呈双峰曲线。小麦强势粒GMP>100μm颗粒数目百分比和体积百分比均显著高于弱势粒,强势粒具有更多的大粒径GMP颗粒。小麦HMW-GS含量和GMP含量与<10μm和<100μmGMP颗粒体积百分比均呈显著或极显著负相关,与>100μmGMP颗粒体积百分比呈显著或极显著正相关,说明大粒径GMP颗粒具有较高的HMW-GS含量。

Glutenin macropolymer （GMP）, the important component of wheat （Triticum aestivum L.） glutenin polymer, consists of high molecular weight gultenin subunits （HMW-GS） and low molecular weight gultenin subunits （LMW-GS）. Accumulations of HMW-GS and GMP play key roles in grain quality of wheat. According to recent studies, GMP is a particle network in endosperm of wheat. The content of GMP is affected by HMW-GS accumulation and environment factors. But to date, there are few reports about the relationship between HMW-GS accumulation and GMP particle distribution. To study the HMW-GS accumulation and its relation to GMP particle distribution, a pool experiment was carried out with wheat cultivar Shannong 12 grown under three soil textures. Forty spikes were sampled at 7, 14, 21, 28, and 35 d after anthesis, and partitioned into two groups, superior grain （the 2nd grain from the basal part of a spikelet） and inferior grain （the 4th grain from the basal part of a spikelet）. HMW-GS was separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis （SDS-PAGE）. The result showed that all HMW-GS already formed at 14 d after anthesis both in superior grain and inferior grain. Higher HMW-GS content showed that superior grain had strong HMW-GS accumulating ability than inferior grain. HMW-GS accumulation and GMP content of wheat grown in clay loam soil were higher than those in sandy and loam soil, which indicated that clay loam soil was suitable for accumulating of HMW-GS. The diameter of GMP particle was in 0.37-245 um, it changed in the pattern of two-peak curve in volume and surface area distribution, while single-peak curve in number distribution of GMP particle. The percentages of number and volume of 〉100um GMP particle were higher in superior grain than in inferior grain. The contents of HMW-GS and GMP were negatively correlated with GMP particle volume of 〈10 um and 〈100 um, but positively correlated with that of 〉100 um. It is suggested that larger GMP particle has more HMW-GS content.