非充分灌溉条件下水稻根系伤流量变化规律研究

Study on Change Rule of the Bleeding Amount of Rice Roots under Deficit Irrigation Condition

[目的]为水稻的非充分灌溉提供了科学依据。[方法]以水稻汕优63号为试材,在5个主要生长期,设正常供水、受旱5 d、受旱10 d、受旱15 d 4个处理,研究了单株植物伤流量的变化情况。[结果]正常供水单株根系伤流量到拔节孕穗后期至抽穗开花前期达到高峰值,以后逐渐减小。单株根系伤流量与生育进程天数之间的回归方程为:y=-0.001 2x3+0.166 8x2-4.806 3x+43.146(R2=0.972 1)。同一个生育期内胁迫程度越大,根系伤流量就越小,相对含水量低于30%时,根系伤流量几乎为零。抽穗开花期干旱的影响最严重,分蘖前中期的影响最小。[结论]单株水稻根系相对伤流量与相对土壤含水量的回归方程为:y=-0.026 6x2+4.694 3x-116.190 0(R2=0.786 9)。

[ Objective] The study was to provide a scientific basis for the deficit irrigation on rice. [Methed] With Xanyou 63 as tested material,4 treatments as normal water supplied,drought 5d,dronghts 10d and droughts 15d were designed at 5 main growing stage,and the change of the bleeding per plant was investigated. [ Result ] The bleeding amount per plant roots at normal water supply reached the peak value from late stage of jointing and beothag and early stage of heading and flowering, then gradually decreased. The regression equation between the bleeding amount per plant roots and days number of growth process was y = - 0.001 2x^3 ＋ 0.166 8x^2 - 4.806 3x ＋ 43. 146 0（ R^2 = 0.972 1）.The bigger the stress degree was at a same growth period, the smaller the bleeding of of roots was, and when the relative water content was low than 30%, the root bleeding amount was nearly 0. The influence of drought in heading and flowering stage was most serious and that was smallest in early and middle of tillering stage. [ Conclusion] The regression equation between bleeding amount and relative soil water content was y = -0.026 6x^2 ＋4.694 3x - 116.190 0（R^2 =0.786 9）.