Study On Pod Photosynthesis And Photosynthate Transporting And Acting Mechanism In Alfalfa

With development of seed, changing of chlorophyll-a concentration, chlorophyll-b concentration and chlorophyll concentration of pod and leaf was researched in alfalfa. The results showed that there was no significant difference between Zhongmu No.2and Gannong No.6. The chlorophyll-a concentration, chlorophyll-b concentration and chlorophyll concentration of pod and leaf decreased gradually at the stage TO to T4. The hlorophyll-a concentration, chlorophyll-b concentration and chlorophyll concentration of leaf was higher than pod. The hlorophyll-a concentration, chlorophyll-b concentration and chlorophyll concentration of leaf was7.8,6.9and7.5times as much as pod, respectively.The changing of RuBP carboxylase and PEPC carboxylase activity of pod and leaf was researched at stages T1to T4in alfalfa. The results showed that the RuBP carboxylase activity of pod was no significant difference between Zhongmu No.2and Gannong No.6. With development of seed, the RuBP carboxylase activity of pod decreased gradually, but it increased first and then decreased in leaf. The PEPC carboxylase activity of pod was significant difference between Zhongmu No.2and Gannong No.6, but there was no significant difference between Zhongmu No.2and Gannong No.6in leaf. During the development of seed, the PEPC carboxylase activity of pod firstly increased and then decreased, but it was gradual decrease in leaf. The PEPC carboxylase activity of leaf was5.5times more than pod in alfalfa.During the process of seed development, the changing of Pn in pod and leaf was researched in alfalfa. The results demonstrated that there was significant difference between Zhongmu No.2and Gannong No.6. The Pn of pod and leaf in Gannong No.6was1.46and1.08times higher than Zhongmu No.2, respectively. The Pn of pod and leaf decreased gradually at the stage T1to T4. The Pn of leaf was more than2.32times of pod in alfalfa. Gs of pod and leaf was significant difference between Zhongmu No.2and Gannong No.6. The Gs of pod and leaf in Gannong No.6was2.36and1.28times as much as Zhongmu No.2, respectively. The Gs of pod firstly increased and then decreased, but it gradually decreased in leaf. The Gs of leaf was as1.19times as pod in alfalfa. The E of pod and leaf was significant difference (except pod at stages T3and T4) between Zhongmu No.2and Gannong No.6, and the E of pod and leaf in Gannong No.6was1.79and0.54times of Zhongmu No.2, respectively. The E of pod and leaf gradually declined at the stages T1to T4. Bur the E of leaf was1.37times as much as pod in alfalfa. The Ci of pod and leaf was significant difference between Zhongmu No.2and Gannong No.6, and the Ci of pod and leaf in Gannong No.6was1.43and0.75times as strong as Zhongmu No.2, respectively. The Ci of pod and leaf increased step by step at the stages T1to T4. The Ci of leaf was as0.77times as pod in alfalfa.According to the results of13CO2labeling of pod and leaf, it suggested that there was photosynthetic capacity for alfalfa pod especially during its early development and the carbon needs of the alfalfa organs such as seed, pod, leaf, stem and root were supplied not only by leaf but also by pod photosynthesis. The assimilated13C of the pod was the fate to the growth needs of seed and pod within the plant. With the seed developing and maturity, the requirement of assimilated C in the seed mainly came from the young pod, exchanged to mainly come from the leaf at the later. The assimilated13C of pod was mainly sourced from the pod labeling33.25%, which was retained in the pod to maintain own requirement, in addition, it also transported14.29%,12.65%,14.23%,15.67%,6.07%and3.83%assimilated C to the SEED, L1, L2, L3, S and R, respectively. And the assimilated13C of leaf was mainly sourced from the leaf labeling25.95%,33.24%,28.33%, and retained in the L1, L2and L3to make itself C satisfied, besides it transporded assimilated C14.29%,2.92%,3.59%,4.89%and1.08%to the P, SEED, S and R, respectively.The different photosynthetic capacity was controned by the PEPC carboxylase activity of pod between Zhongmu No.2and Gannong No.6. But it was regulated by the chlorophyll concentration, RuBP carboxylase and PEPC carboxylase activity between pod and leaf in alfalfa.