玉米深层根系对地上部营养生长和产量的影响

Effects of Deep Root System on Above-ground Vegetative Growth and Yield in Maize

采用切断土柱根系方法 ,研究了在玉米拔节期和抽雄期时土表 2 0cm和 4 0cm以下根系对玉米杂交种四密 2 1和掖单 19地上部营养生长和产量及其构成因子的影响。结果表明 ,与不断根相比 ,在抽雄期切断 2 0cm深处根系 ,使四密 2 1和掖单 19株高分别降低 37.1cm和 32 .1cm ,叶绿素总量降低 2 0 .0 %和 37.0 % ,光合速率降低2 1.6 %和 19.6 % ,百粒重降低 12 .1%和 9.0 % ,穗粒数减少 18.8%和 17.5 % ,产量降低 2 6 .2 %和 2 0 .0 %。切断土层4 0cm深处根系 ,株高分别下降 2 3.5cm和 2 3.6cm ,百粒重下降 10 .1%和 5 .2 % ,穗粒数减少 13.1%和 12 .0 % ,产量降低 2 1.5 %和 18.6 %。拔节期断根使叶绿素含量显著降低 ,切断 2 0cm深处根系使四密 2 1和掖单 19叶绿素降低13.6 %和 2 5 .2 % ,切断 4 0cm深处根系使叶绿素下降 10 .4 %和 14 .2 %。切断根系对玉米产量的影响 。

Effects of maize root system below 20cm and 40cm deep in soil on the vegetative growth, yield and its composition factors in hybrids of Simi 21 and Yedan 19 were studied by cutting root in soil column at elongation stage and heading stage. The results showed that as compared with without cutting root, cutting root at 20 cm soil depth at heading stage decreased height of Simi 21 and Yedan 19 by 37.1 cm and 32.1 cm ,and chlorophyll content by 20.0% and 37.0 %, and photosynthetic rate by 21.6% and 19.6%,and 100-grain weight by 12.1% and 9.0, and grain number per ear by 18.8% and 17.5%, and yield by 26.2% and 20.2% respectively. Cutting root at 40 cm soil depth at heading stage reduced height of Simi 21 and Yedan 19 by 23.5 cm and 23.6 cm ,and 100-grain weight by 10.1% and 8.2 %,and grain number per ear by 13.1% and 12.0%, and yield by 21.5% and 18.6% respectively. Cutting root at elongation stage reduced chlorophyll content significantly,chlorophyll content of Simi 21 and Yedan 19 reduced by 13.6 % and 25.2% with 20 cm deep cutting root and by 10.4% and 14.2% with 40 cm deep cutting root. Reduction in the maize yield was higher at heading stage than at elongation stage.