施氮水平对优质小麦旗叶光合特性和子粒生长发育的影响

Effects of nitrogen application rate on flag leaf photosynthetic characteristics and grain growth and development of high-quality wheat

通过对两个优质小麦品种不同施氮量的比较试验，研究了氮素水平对优质小麦生育后期旗叶光合特性和子粒生长发育特点及产量的影响。结果表明，强筋小麦8901施氮量在N120～360kg／hm^2范围内，旗叶光合速率、蔗糖含量、淀粉含量和粒重都表现为随施氮量的增加而降低。弱筋小麦SN1391施氮量在N120～240kg／hm^2的范围内，上述指标和施氮量呈正相关，但当氮肥用量增加到360kg／hm^2时，则迅速降低。研究还表明，两优质小麦都表现为随施氮量的增加叶绿素含量提高，但过高氮肥用量又使其降低；旗叶叶绿素含量和其光合速率之间相关不显著；旗叶光合速率和粒重之间存在正相关。

Using pool culture method, the effects of nitrogen rate on photosynthetic rate of flag leaves, kernel growing and developing characteristics as well as yield of two high-quality wheat cultivars were studied. The results indicated that the photosynthetic rate, sucrose content, starch content and kemel weight of strong-gluten wheat 8901 were getting lower with the increasing of N application rate in the range of N 120-360 kg/ha. These indexes of weak gluten wheat SN1591 had a positive correlation with the N application rate in the range of N 120-240 kg/ha, but they decreased sharply when the N application rate increased to 360 kg/ha. In 120-240 kg/ha. Chlorophyll content of both two gluten wheat cultivars went up along with the increasing of N application rate, while it declined if N application rate was excess（240-360 kg/ha）. The results also showed that photosynthetic rate was positively correlated with kernel weight, but the correlation between chlorophyll content and photosynthetic rate was not statistically significant.