冬季干旱对小麦苗期生长发育的影响

Effects of Winter Drought on Growth and Development of Wheat Seedlings

为研究冬季干旱对冬小麦生长的影响,在大田条件下,以济麦20为材料,在苗期进行不同的水分处理:冬季自然干旱、正常灌溉处理和过量灌溉处理,并于返青期对干旱处理复水并正常管理。复水前后对各处理的各特征进行测定。实验结果表明,冬季干旱对小麦影响涉及诸多方面:干旱组叶片光合速率、叶绿素含量、Fv/F0、ΦPSII都有所减小;气孔导度降低,蒸腾速率降低;根系活力降低,根密度降低,但根生长粗壮,根冠比增加;缺水引起小麦体内脯氨酸含量积累;春前分蘖相对较少,但分蘖粗壮少弱株。冬季干旱下冬小麦生长受到一定影响,但春季复水后表现出良好的长势,可迅速赶上甚至超过灌溉条件下越冬的小麦。所以适当程度的冬季干旱有利于冬小麦后期的生长发育。

To study the effects of winter drought on the growth of winter wheat, Jimai20 was used as experimental materials, involving 3 different water treatments： winter natural drought, normal irrigation treatment and over-irrigation treatment, together with rewatering treatment during wheat re-greening stage to be followed with normal management. The characteristics before and after rewatering were measured. The experimental results show that the impact of drought on winter wheat is represented in many aspects, for instance, photosynthetic rate, chlorophyll content, Fv/F0, φPSII which would be reduced with the drought treatment. Stomatal conductance and transpiration rate will be reduced too. Root activity is reduced and root density becomes lower, but the root growsstronger and the root-shoot ratio is increased. Accumulation of proline content in wheat is increased because of water shortage. The tilling stems are relatively few before spring but they become very robust. After winter drought, the wheat grows well after rewatering treatment and the growth potential can reach and even exceed that with the irrigation treatment in winter. So, an appropriate level of winter drought is conductive to the growth of winter wheat in the late growth period.