On the basis of the phytotron, the effects of high temperature （daily average temperature 25, 30, 35 and 40℃, respectively） on antioxidant enzymes and lipid peroxidation in flag leaves of wheat at 50% relative air moisture during grain fastest filling stage [19-21 days after anthesis （DAA）] were studied. The wheat cultivars tested were Yangmai 9 with weak-gluten and Yangmai 12 with medium-gluten. Compared with 25℃, the higher the temperature was, the higher was the MDA content in flag leaves, while lower were the SOD, POD, and CAT activities. SOD and CAT activities in Yangmai 12 appeared to be more sensitive to high temperature than that in Yangmai 9. But POD activity in Yangmai 12 was less sensitive to high temperature. MDA content in Yangmai 12 was higher than that in Yangmai 9. The 1000-grain weight declined with increase in temperature.
LIU Ping GUO Wen-shan PU Han-chun FENG Chao-nian ZHU Xin-kai PENG Yong-xin
以不同类型小麦品种为材料,研究籽粒形成灌浆过程中多酚氧化酶(PPO)活性和戊聚糖含量动态变化,以及二者在籽粒中分布及其与面粉白度的关系。结果表明:小麦籽粒中PPO主要分布在籽粒外层,面粉白度和籽粒中PPO活性呈极显著负相关,面粉中PPO活性与面粉白度呈负相关,但不显著;籽粒形成与充实过程中,PPO活性呈先上升后下降再上升趋势,开花至花后21 d左右时,呈先上升后下降趋势,花后21 d PPO活性迅速上升,至成熟期达最大值;戊聚糖在小麦籽粒中的分布具有由内到外逐渐增加的特性,面粉和麸皮中戊聚糖含量与白度呈显著负相关,随着戊聚糖含量的增加,面粉白度逐渐降低,不同小麦品种籽粒戊聚糖含量的动态变化表现较为一致,均呈先上升后下降再上升趋势。
