| The experiment using 16~18 years Red Fuji (Malus domestica) apple in the field and 2 years young apple tree in pot as materials, the experiment was carried out in Chaoquan apple orchard and Shandong Agricultural University from 2008 to 2010. To study the effect of photosynthetic rate, fluorescence properties, elements and distribution, carbohydrates and related enzymes under different zinc levels. And to explore the effect of growth and development in different zinc levels and provide a guidance for cultivation. The main results are as follows:(1) The chloroplast membrane structure was destoried under zinc deficiency. The number of chloroplast increased and the size changed, also the starch grains became large and increased with the lipid appeared.(2) Net photosynthetic rate was decreased under both zinc deficiency and zinc excessive, and stomatal conductance decreased, and the intercellular CO2 concentration increased, The single area decreased greatly, and the specific leaf weight decreased, but the results were not obvious in pot experiment.(3) Zinc plays an important role in maintaining the function of PSâ…¡. PSâ…¡can be distoryed under both zinc deficiency and zinc excessive. PSâ…¡maximum photochemical efficiency and the effective quantum yield of PSâ…¡all significantly decreased. The donor side, receptor side and the reaction center were damaged at the same time, thus limited the light energy absorption, transmission and utilization, which further lowered photosynthesis.(4) Chlorophyll a chlorophyll b and carotenoids content were decreased under both zinc deficiency and zinc excessive, and the ratio of Chlorophyll a /Chlorophyll b, Chlorophyll (a+b)/Carotenoids also decreased.(5) The root growth was changed by the level of zinc nutrition. There were three peaks for root growth in field, respectively for April, June and September, but potted experiment root vigor has two peaks with the change of the temperature, respectively in June and September. But the change of root vigor was not obvious in different level of zinc supplyment.(6) Zinc content in upper and middle leaves increased with more zinc supplyment, and two turning points appeared in July and August. But the zinc content in below leaves tended to a decreased level.(7) The carbohydrates provide energy for plant growth and were involved as a component in the reconstruction of the new organ. Sorbitol content in the upper leaves was lower than that in middle and below leaves, but the content of sucrose showed in a contrary way. The content of sorbitol, sucrose and starch increased, but glucose decreased with the increased level of zinc.(8) Zinc is the component of many coenzyme and plays an important role in carbon metabolism. The apple leaves maintained a higher SDH activity, SS activity and Amylase active but a lower NI activity, AI activity and A6PR activity; SPS activity finally increased before a decrease with more application of zinc.(9) The results from zinc and carbon interaction experiment showed that, the photosynthetic rate and the chlorophyll content increased, the root development was improved, main root length and thick were increased, lateral root number, length and the area of surface were all especially increased. The abilities of zinc absorption and distribution were significantly strengthened with the use of exgen carbon as well as promoting the balance of mineral nutrition among different organs of tree.
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