半湿润区农田生态系统氮肥对不同基因型冬小麦产量构成的影响

Effects of nitrogen fertilizer on yield components of different genotypic winter wheat in sub-humid farmland ecologic system

施N对“NR9405”、“9430”、“偃师9号”、“小偃6号”、“陕229”、“西农2208”、“矮丰3号”和“商188”这8种不同基因型冬小麦产量构成影响的田间试验结果表明,单株分蘖成穗数、单位面积粒数和单位面积株数的差异同时受基因和N素营养水平控制。“矮丰3号”和“小偃6号”单株分蘖成穗数最多,分别为2.00分蘖穗/株和1.72分蘖穗/株,“9430”最少,为0.85分蘖穗/株。从不同基因型看,施N比不施N处理增加0.74穗/株,每穗粒数在不同基因型间存在极显著差异,以“西农2208”最多,为36.73粒/穗,“NR9405”最少,为24.35粒/穗,施N对每穗粒数无显著影响。单位面积株数主要受施N影响,基因型间差异相对较小。基因型和施N同时显著影响单位面积粒数和千粒重,但基因型对千粒重的影响程度大于N肥。从2个施N水平看,单位面积籽粒产量存在显著差异,“矮丰3号”、“西农2208”、“偃师9号”、“陕229”、“9430”、“小偃6号”、“商188”和“NR9405”依次减小,“矮丰3号”为435g/m2,“NR9405”为316g/m2,相差119g/m2。施N可极显著增加单位面积籽粒产量,不同基因型施N处理平均产量为463.38g/m2,不施N处理为296.13g/m2,相差167.25g/m2,N肥对产量的影响主要与施N增加了单位面积穗数和千粒重有关。

A field experiment was carried out in the south part of Loess Plateau with 632mm precipitation and eight win- ter wheat varieties, ＂NR9405＂, ＂9430＂, ＂Yanshi No. 9＂, ＂Xiaoyan No. 6＂, ＂Shan229＂, ＂Xinong2208＂, ＂Aifeng No. 3＂ and ＂Shang188＂were used as indicating crops to study the effects of nitrogen fertilizer on the yield components of different genotypic winter wheat. The results show that there is a significant difference of ears per unit area, kernels per unit area, tillers per plant,proportion of tillers in the total ears at maturity, kernels per spike, 1000 kernel weight, grain volume, grain bulk density, yield per unit area among different genotypic winter wheat. The application of nitrogen fertilizer has a positive effect on plant spike, grain yield per unit area, 1000 kernel weight, and has no significant effect on harvest index. Increase of spike per unit area and valid tillers per plant causes the decrease of 1000 kernel weight; also increasing kernel volume causes the increase of 1000 kernel weight. Spikes grains, tillers per unit area, proportion of tillers in the total areas, kernel weight per plant are the main factors affecting the wheat＇s yield.