氮肥对半湿润区不同基因型冬小麦籽粒灌浆特性的影响

以9430、小偃6号和商188为供试材料，在年均降水量632 mm的黄土高原南部半湿润红油土上进行田间试验，研究不施氮和施氮条件下3种基因型冬小麦的灌浆特性.结果表明，遗传差异是控制小麦籽粒灌浆特征参数的主要因素，最大灌浆速率持续期、活跃灌浆期和达到最大灌浆速率的天数在不同基因型间存在显著差异；从基因型差异看，商188、小偃6号和9430的最大灌浆速率持续期分别为17.20、14.15和14.13 d，达到最大灌浆速率的天数分别为28.14、23.90和23.89 d，活跃灌浆期分别为29.00、26.40和26.88 d，商188显著大于9430和小偃6号，而小偃6号与9430间差异不显著.氮肥与基因间存在互作，但总体上氮肥对这些参数的影响相对较小.最大灌浆速率持续期、达到最大灌浆速率的天数、活跃灌浆期与千粒重呈极显著正相关关系，其相关系数分别为0.825、0.679和0.627(P<0.01)，是影响粒重的关键因子.

Grain-filling characters of different genotype winter wheat under nitrogen fertilization in semi-humid area of south Loess Plateau

A field experiment was conducted in the south part of Loess Plateau with 632 mm precipitation each year. Three genotypes winter wheat 9430, Xiaoyan No. 6 and Shang188 were used as test materials to study their grain-filling characters under two nitrogen application levels (0 and 90 kg x hm(-2)). The results showed that genetic difference was the main factor affecting grain-filling characteristics, while nitrogen fertilization had a less effect. There were significant differences among genotypes in the duration of maximum grain filling rate (GFRmaxD), active grain-filling period (D), and the days reaching to the maximum grain-filling rate (GFRmaxGD). For Shang188, Xiaoyan No. 6 and 9430, the GFRmaxD was 17.20, 14.15 and 14.13 d, D was 29.00, 26.40 and 2688 d, and GFRmaxGD was 28.14, 23.90 and 23.89 d, respectively. All the parameters of Shang188 were significantly bigger than those of 9430 and Xiaoyan No. 6, while those of the latter two had no significant difference. There was an interaction between nitrogen fertilization and genotype, but the effect of nitrogen fertilization on the three parameters was relatively small. 1000 kernel weight had a significant positive correlation with GFRmaxD, GFRmaxGD and D, suggesting that the three parameters were the main factors affecting grain weight.