Taking the heat-sensitive wheat variety 'Fanmai 5' (FM5) and the heat-tolerant variety 'Huaimai 33' (HM33), which were screened out in the previous experiments, as experimental materials, we conducted a field experiment with passive heat-enhancing shelters to simulate post-flowering high-temperature environment (average temperature increase of 5.13 ℃) during 2021-2022. During the filling period, we analyzed the effects of exogenous trehalose (10, 15 and 20 mmol·L-1) on the filling characteristics and sugar fraction under high temperature, with no spraying at ordinary temperature as control (CK). The results showed that treating without spraying exogenous trehalose at high temperature (H) significantly reduced wheat grain yield and grain weight during the filling period, and spraying exogenous trehalose alleviated the reduction of grain yield and grain weight at the filling stage under high temperature stress. Compared with the H treatment, grain yield and grain weight of HM33 and FM5 wheat varie-ties increased by 3.5%, 6.7% and 4.2%, 5.4%, respectively. High temperature stress significantly increased the trehalose content and trehalase (THL) activity in flag leaves of both wheat varieties, and decreased the fructose and glucose contents. Spraying exogenous trehalose increased the contents of trehalose, fructose, and glucose in flag leaves, and decreased the trehalase activity in flag leaves compared with H treatment, which could improve the glucose metabolism capacity of wheat at filling stage. The increasing effect of FM5 was higher than that of HM33. High temperature stress significantly reduced starch content of flag leaves and grains, while spraying exogenous trehalose alleviated the decrease of starch content of flag leaves and grains under high temperature stress, which was profit able for the substance accumulation of wheat grains under high temperature stress. Under the conditions of this experiment, spraying 15 mmol·L-1 trehalose at flowering stage was the best treatment for the two wheat varieties.
本研究于2021—2022年,以前期试验筛选出的热敏感型小麦品种‘泛麦5号’(FM5)和耐热型品种‘淮麦33’(HM33)为试验材料,采用大田种植方式,以被动式增温棚模拟花后高温环境(平均增温5.13 ℃),设置常温喷施清水对照(CK)和喷施清水+灌浆期高温胁迫处理(H),分析外源海藻糖(喷施浓度为10、15、20 mmol·L-1)对灌浆期高温胁迫下小麦灌浆特性和糖组分含量的影响。结果表明:与CK相比,高温胁迫(H)显著降低了小麦籽粒产量和灌浆期粒重,外源喷施海藻糖缓解了高温胁迫下小麦籽粒产量和灌浆期粒重的降低,与H处理相比,HM33和FM5两个小麦品种平均分别提高了3.5%、6.7%和4.2%、5.4%;高温胁迫显著提高了两个小麦品种旗叶海藻糖含量及海藻糖酶(THL)活性,降低了果糖和葡萄糖含量,与H处理相比,外源喷施海藻糖提高了小麦旗叶海藻糖、果糖和葡萄糖含量,降低了旗叶海藻糖酶活性,有利于提高灌浆期小麦的糖代谢能力,且对FM5的提升效果高于HM33;高温胁迫显著降低了小麦旗叶和籽粒的淀粉含量,外源喷施海藻糖缓解了高温胁迫下小麦旗叶和籽粒淀粉含量的降低,有利于高温胁迫下小麦籽粒的物质积累。本试验条件下两个小麦品种均以开花期喷施15 mmol·L-1海藻糖效果最佳。.
Keywords: filling characteristics; high temperature stress; sugar component.; trehalose; wheat.