再生稻茎生腋芽的生育特性观察
Growth characteristics of stem auxiliary buds on ratoon rice
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摘要: 为探索再生稻高产途径,观察了各节位茎生腋芽的分化、生长、穗粒发育性状和茎生器官形态。结果表明:茎生腋芽在母茎抽穗前按由下而上的节位顺序开始幼穗第一苞分化,在母茎抽穗后按由上而下的节位顺序进入一、二次枝梗分化;在顶端优势控制下,茎生腋芽至母茎黄熟前3 d才开始萌发,萌发成穗率随节位下移而降低,且生长先天不足,每穗粒数仅为母茎的三分之一。争取再生季高产的关键,是在头季收割保留上位优势芽的基础上,大力提高下部茎生腋芽的萌发率,形成比头季多70%~100%的穗数,以多穗补小穗的不足。倒3叶枕比倒2芽着生节部高8~16 cm,其高程可作为简捷诊断母茎适宜留桩高度的形态指标。Abstract: In order to improve yield of the ratoon rice,differentiation and growth of the stem auxiliary buds on different nodes,development traits of the ear grain and morphology of the stem organs were studied.The results indicated that(a) the differentiation of rachis primordial of the stem auxiliary buds began from bottom up before the mother stem heading;(b) after the mother stem heading,the differentiation of primary or secondary rachis branch occurred in a top down order;(c) under the apical dominance,the stem auxiliary buds began to germinate 3d before the mother stem ripened;and(d) the panicle bearing tiller rate decreased and the grains per spike reduced to one-third of the mother stem,as the node moving downward due to congenital deficiencies.Thus,boosting germination rate of the stem auxiliary buds in the lower nodes while retaining upper buds at initial harvest could improve the yield.By forming 1.70-2.00 folds spikes more than the initial rice,the yield could be increased.The converse 3rd pulvinus was 8-16 cm higher than converse second buds,and its height could be used as a quick morphological index for optimum stubble height of the mother stem.