大豆光合生理生态的研究——第16报 去荚对大豆比叶重和光合速率的影响

大豆生殖生长时期,去荚植株的比叶重随生育进程增加的幅度较大,但叶片光合速率和全N含量(％)在去荚后短期内低于对照,随后尤其R_7和R_8期则显著高于对照。去荚延缓了叶片衰老,提高鼓粒末期叶片的光合速率和光呼吸速率。 荚果生长在一定时间内确能提高叶片光合速率,鼓粒末期叶片光合速率的明显降低是衰老的主要征状之一。

EFFECT OF DEPODDING ON SOECIFIC LEAF WEIGHT AND PHOTOSYNTHETIC RATE OF SOYBEAN

To determine the importance of the relationship between source and sink in soybeans ( Glycine maxL. Merrill) , field-grown plants were used as the experimental materials during reproductive stages in 1989 and 1990. From R1 to R8, flowers and pods were removed daily; specific leaf weight, total leaf N content, leaf photosynthetic rate and other leaf photosynthetic traits were determined in each reproductive stages.From early to late reproductive stages, the specific leaf weight of treatrnent poup increased more obviously than that of control ones. The leaf photosynthetic rate and total N content (%) slightly decreased at early reproductive stages but enhanced soon after Ra stage and was obviously higher in treatment group than that in control ones at later stagey, Depodding enhanced the leaf photorespiration rate and CO2 complementary point at late pod - filling stages.The results indicated that the leaf phoTosynthetie rate were enhanced by the growth ol fruits while the leaf photosynthetic rate were'decreased by the leaf senescence at pod-filling stage.