CPPU和PP333对杂交稻3个淀粉合成酶活性和米质的影响

在抽穗期和抽穗期后12d对两系杂交水稻培杂青珍喷施CPPUN-(2-氯－4－吡啶基）－N'－苯基脲]和PP333（多效唑）溶液。结果发现，CPPU和PP333能提高籽粒的可溶性淀粉合成酶（SSS）、结合性淀粉合成酶（GBSS）和淀粉分支酶（SBE）活性，其增加以SSS和SBE明显高于GBSS，而GBSS活性具有相对的稳定性。同时，能提高精米率、整精米率和胶稠度，而降低垩白粒率、垩白度和直链淀粉含量，有利于改良米质。其中，以抽穗期用质量浓度为10mg/L的PP333溶液喷60ml/m^2 抽穗期后12d用质量浓度为2mg/L的CPPU溶液喷施75ml/m^2的处理对促进SSS、SBE和GBSS活性提高与改良品质的作用最大。

Effects of CPPU and PP333 on Three Starch Synthase Activity and Grain Quality of Hybrid Rice

CPPU N-(2-choro-4-pyridyl)-N-phenylurea] and PP333 (paclobutrazol) were sprayed on two-line hybrid rice Peiza Qingzhen at heading and 12 d after heading, respectively. The results showed that CPPU and PP333 increased the activity of soluble starch synthase(SSS), starch branching enzyme(SBE) and granular bound starch synthase(GBSS) in grains.The extent of increase in the activity of SSS and SBE was greater than that in GBSS activity, which indicates GBSS is relatively stable in its activity. CPPU and PP333 also increased the percentages of milled rice and head rice and gel consistency but decreased chalky rice percentage, chalkiness and amylose content, which benefited the improvement of rice quality. The treatment of spraying 60 ml/m 2 of 10 mg/L of PP333 at heading stage plus 75 ml/m 2 of 2 mg/L CPPU at 12 d after heading had the best effect on the increase of the activity of SSS,SBE and GBSS and on the improvement of rice quality among all treatments.