高产冬小麦群体呼吸速率变化与光合作用关系的研究

研究表明,小麦群体呼吸速率在整个生育期的变化是单峰型曲线,开花前后达最大值.大群体的呼吸速率高于小群体,其高峰期出现早,后期下降迅速.群体呼吸速率的日变化主要受气温的影响.群体呼吸速率所占总光合的比例因不同生育时期、不同品种、不同密度而异.拔节—孕穗;灌浆中期—成熟是小麦一生中呼吸比例较高的两个时期.两个品种全生育期呼吸/总光合的值平均为31.4%.基本苗少的处理呼吸/总光合的值依次低于基本苗多的处理.小麦群体呼吸速率与每亩分蘖数、叶面积系数、干物重之间,在孕穗期前呈显著正相关,与经济产量亦呈正相关,但未达显著水平.群体呼吸速率高是群体生长旺盛的表现,但生产上要适当限制过高的群体呼吸消耗.减少基本苗可以适当降低群体呼吸消耗,对籽粒产量是有利的.

Studies on Relationship Between Canopy Respiration and Photosynthesis in High Yield Winter Wheat

Experiment results showed that the change in the canopy respiration rate (CRR) of winter wheat was a single peak curve through the whole growth period. Maximum values of CRR occurred before or after the anthesis stage. The value of CRR was greater and the maximum value emerges earlier and decreases faster in the high density population than in the low density population. Daily changes of CRR were affected by temperature. The ratio of CRR to the canopy photosynthesis rate (CPR) varies in accordance with the growth stage, variety and density. The jointing-booting and the middle-period filling-maturing periods are two high ratio periods. The mean value of CRR/CPR in the whole growth stage is 31.4%.The CRR/CPR ratio of the low density population is lower than the high density population. The number of tillers per mu, the leaf area index and the dry matter weight exhibited a significant correlation with CRR before the booting stage. The correlation of CRR with yield was positive but not significant. Decreases in the number of basic seedlings could decrease the CRR/CPR ratio, and are favourable to grain yield increases.