Comparison On Some Photosynthetic Characteristics Of Leaves In The Different Evolutionary Types Soybean

In order to investigate the regulation of photosynthesis and the contribution to yield during the change of cultivar and the improvement of yield, explicit the relationship of photosynthesis and yield in different stages, and provide theoretical basis to the breeding and cultivation, the photosynthesis of 12 semi-wild, semi-cultivated, cultivated soybean and 31 soybean cultivated in past 83 years were studied, planted in the same environment and cultivated condition. Research work was conducted at experimental station of Jilin Agricultural University, Changchun city, Jilin Province PR. of China (125. IE longitude 43.53N Latitude ) in 2004 and 2005. The annual precipitation is in the range of 500-700mm; 10℃ accumulated temperature is 2860℃; annual average temperature is 4.6℃. The result showed that:1.The research of photosynthesis in leaf of semi-wild, semi-cultivated and cultivated soybean showed that: The Pn, (5s, WUE, Chlo and SLW of semi-wild, semi-cultivated and cultivated soybean were increased with the evolution of cultivars, and there was significant difference at every stage(P<0.05). Tr was decreased with the cultivars of release, and also difference significantly at every stage. The change of Ci was complicated. The Ci of cultivated soybean was higher than semi-wild and semi-cultivated soybean at V4 and R4 stage ,and there was very significant difference(P≤0.01).But the difference was little at R4 stage, and semi-wild>cultivated soybean>semi-cultivated soybean at R2 stage, and the difference was significant(P≤0.05).Through this analysis, we conclude that with the improvement of structure and function of soybean's photo-system, the function of photosynthesis was increased, then the matter production was increased during the year of release. So that ,the necessary condition to breed soybean of high yield is increase the time of green leaf ,regulate the water and fertile at every stage, then heighten the photosynthesis ability.2.The soybean of different years: soybean yield has increased 868.1kg.ha-l(71%) in past 82 years, As the years of release, Pn, Gs, Tr, Chlo and SLW of leaf were increased at every stages. Pn was positively correlated with year of release, but Pn and SLW were the most positively correlated with year of release at R2 stage; Chlo was the most positively correlated with year of release at R4 stage; and Tr was the most positively correlated with year of release at V4 stage; but the correlation of Gs and year of release was not significant at every stage. At mature stage, WUE and Ci were decreased, and negative...