Effects of winter drought on growth and development of wheat seedlings.

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 re watering 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.