Study On The Lodging Resistance Techniques Of Seed Production For Two-line Hybrid Early Rice Combination Zhuliangyou02

Zhu1S line is a widely used production TGMS line.A series of two-line early hybrid rice combination have been bred in use of this sterile line,applied in the production of large area.But the lodging problem of Zhu1S in seed production is still serious,which has bad effect to the seed yield and quality.The study includes three experiments to the Zhuliangyou02 combination in seed production:the GA3 test,the Paclobutrazol test,the Silicon fertilizer test.The study analyses the lodging causes of Zhu1S,the controlling effects of Paclobutrazol and Silicon fertilize to Zhu1S,the main results are as follows:1.The lodging of Zhu1S usually cccurs at the fifty percent area below the middle line of the fourth or the third node after spraying GA3.The plant height and biomass per plant were correlated to the lodging index at the 1%level of significance.Besides the plant height and the biomass per plant,the first and the second internodes length were the most two positive factors to the lodging index,which were correlated to the lodging index at the 1%level of significance.The internodes length of the fourth and the third nodes were negatively correlated to the breaking resistance and positively correlated to the lodging index at some extent;the basal inernode walls of the fourth and the third nodes were positively correlated to the breaking resistance and negatively correlated to the lodging index at some extent;the culm thickness of the fourth and the third nodes were positively correlated to the breaking resistance and lodging index.The path analysis show,it can effectively augment the breaking resistance by increasing the culm thickness or basal inernode wall of the third node.The breaking resistance is the negative factor to the lodging index which was correlated to the lodging index at the 1%level of significance.Accordingly,it is the effective way to decrease lodging by controlling the elongation of the first and second nodes,or finding other ways to increase the breaking resistance.2.Through the GA3 spraying time and dosage test,we ecludes:It can results in lower lodging index and rate of grain in neck,higher seed-setting rate,unconspicuous effect on 1000-grain weight and germination percentage,spraying GA3 8～12g per 667 m~2 when Zhu1S has 35%hills to heading or 12～16g per 667 m~2 when 45%hills to heading.3.Spraying Paclobutrazol 100～120g per 667 m~2 at the stage of elongating and spraying GA3 16g per 667 m~2 when Zhu1S has 45%hills to heading,can effectively lower the pant height,shorten the forth and the third internodes length,increase the culm thickness of the forth and third node,and the basal inernode wall of the third node,augment the breaking resistance,decrease the lodging index,but leads to unconspicuous effect on 1000-grain weight and germination percentage,a little lower seed-setting rate and a little increasing rate of grain in neck.4.Applying Silicon fertilizer 750～1000g per 667 m~2 at the stage of elongating and spraying GA3 16g per 667 m~2 when Zhu1S has 45%hills to heading,can effectively lower the pant height,shorten the forth,the third and the first internodes length,increase the culm thickness and the basal inernode wall of the forth or the third node,augment the breaking resistance,decrease the lodging index,improve the 1000-grain weight,but leads to unconspicuous effect on seed-setting rate and germination percentage,a little increasing rate of grain in neck.