Effects of spikelet and grain position on fertile spikelet number, grain weight and quality of wheat

صينى. 研究小麦不同小穗位和粒位的穗结实粒数、粒重和品质变化规律。通过田间试验系统研究穗结实粒数相近，粒重和品质不同的3个小麦品种的结实粒数、粒重和品质的小穗位和粒位效应。3个小麦品种不同小穗位籽粒结实粒数、小穗千粒重、粒重、蛋白质含量、干面筋、沉降值、吸水率、稳定时间、评价值和软化度均呈现二次曲线变化趋势分布，第1粒位、第2粒位和第3粒位的粒重及品质也随小穗位的变化呈二次曲线形式，表现出籽粒发育的近中优势。第1粒位和第2粒位的粒重相近，都高于第3结实粒位；第2粒位增产潜力较大，是粒重变化的主要因素；临优2018和临优2069第2粒位，临优145第1粒位的蛋白质含量、干面筋和沉降值较高且变异较大，增质潜力较大，是品质变异的主要因素。在小麦育种和栽培中，对于每小穗最多结实3粒籽粒的品种，应尽量减少小花位数，来保持小麦籽粒品质的稳定性和一致性。

إنجليزي. The experiment was conducted to study the change of fertile spikelet number，kernel weight and quality of wheat with spikelet and grain position. Using field experiment, effect of spikelet and grain position on fertile spikelet number, kernel weight and quality of three wheat cultivars, Linyou 2018, Linyou 145 and Linyou 2069, which have equal fertile spikelet and unequal kernel weight and quality, were studied. Results showed that, fertile spikelet number, spikelet weight, kernel weight, protein content, dry gluten, sedimentation value, dough rheology characteristics in different spikelet positions showed parabolic changes. Kernel weight and quality of the 1st, 2nd, 3rd grain position in different spikelet positions also showed parabolic changes. And this is accord with medial dominant in grain development. Kernel weight of the 1st grain position is close to that of the 2nd grain position, and both higher than that of the 3rd grain position. Grain of 2nd position had bigger potential in improving yield. Coefficient of variation of protein content, dry gluten and sedimentation value of the 2nd grain position in Linyou 2018 and Linyou 2069 was higher than other grain positions, and that of the 1st grain position in Linyou 145 was higher. In conclusion, the 2nd grain position of Linyou 2018 and Linyou 2069 and the 1st grain position of Linyou 145 had bigger potential in improving quality. In wheat breeding and cultivation, as for wheat cultivars, which have no more than three grains in each spikelet, wheat stability quality and uniformity can be obtained simultaneously through little florets.