保花肥对母本柱头外露及结实率的影响

Effects of Spikelet-developing Fertilizer on Stigma Exsertion and Outcrossing of CMS lines in Hyhrid Rice Seed Production

Ｖ２０Ａ在幼穗发育５～６期亩施尿素５～６ｋｇ和钾肥３～５ｋｇ作保花肥，可提高母本柱头外露率１５％左右，可使异交结实率提高１０．８％～１７％。产量增加１０％以上。

In hybrid rice seed production(of V20A× 1126), different amount of urea and potash fertilizerwas applied in the young panicle differentiation stages from the formation of pollen mother cells (Stage Ⅴ ) tomeiotic division(Stage Ⅵ ) as the spikelet--developing fertilizer on the female parent to study the effects onstigma exsertion and outcrossing in CMS lines; The experimental results showed that applying urea 75～90kg/ha and potash fertilizer 45～ 75 kg/ha could increase the rates of stigma exsertion and outcrossing of thefemale by about 15%and l0%, respectively, and raise the seed yield by 10%. The reason is thought to bethe longer, larger stigmas and stronger stigma vigor after the application of the spikelet-developing fertiliz-er.