施硫对小麦子粒形成过程中蛋白质与巯基、二硫键的含量及加工品质的影响

摘要

In order to study the responses of wheat grains protein, sulfhydryl group and disulfide bond content in different spikelet and floret position, flour processing quality to sulphur fertilization, field experiment was carried out with four winter wheat cultivars (Jimai20, Zimail2, Lumai21 and Shannong1391 ). The available sulfur content in the experimental soil was 7. 28 mg/kg. The results showed that the effects of sulphur on grain protein accumulation in upside spikelets were higher than in the other parts of spikelet. The protein contents of inferior grains in the middle spikelets were increased in the high-protein cultivars Jimai20 and Zimail2. The sulphur application could enhance the sulfhydryl group content in the upside and the superior grains of middle spikelets, and the disulfide bond content of grains in the different spikelet positions. However, its effects on disulfide bond of grains in different floret positions varied with the wheat cultivars. The sulphur application could increase the wet gluten content,dough development time, stable time and total evaluation value in the cultivars with high protein to some extent.But the effects on these different quality indices were not homogenous. The improvement of processing quality was attributed to the increase in grain protein, the sulfhydryl group and disulfide bond content. According to the data collected from the experiment, the changing curve of sulfhydryl group content in the grain formation was increased first and then decreased which contrary to that of grain protein content, the changing of disulfide bond content is similar to that of grain protein, but the lowest value occurred later than grain protein.%在土壤耕层有效硫含量为7.28mg/kg的条件下,选用不同冬小麦品种济麦20、淄麦12、鲁麦21和山农1391为试验材料,研究了施用硫肥对小麦不同穗位和不同粒位子粒蛋白质与巯基、二硫键含量及加工品质的影响.结果表明,施用硫肥对上部穗位粒的蛋白质含量的提高作用大于其他穗位粒;增加了高蛋白含量品种济麦20和淄麦12的弱势粒子粒蛋白质含量,增加了上部小穗位子粒和中部穗位强势粒的巯基含量,提高了不同穗位子粒二硫键含量;而对不同粒位子粒二硫键含量的影响则因品种而异.施用硫肥使小麦面粉湿面筋含量、面团形成时间、稳定时间和粉质评价值均有一定提高,但不同品质指标对施用硫肥的反应存在差异.与子粒形成过程中蛋白质含量的变化相反,巯基的含量变化呈先升后降的规律;二硫键的含量变化趋势与蛋白质含量的变化相似,但最小值出现时间略有延迟.