Effects Of Different Experimental Treatments On Chloroplasts Ultra-structure And Photosynthesis Characteristics Of Korla Fragrant Pear

This experiment studied the effect of the chloroplasts ultra-structure and photosynthesis characteristicsin different amount of fertilizer with10years-old and20years-old Korla Fragrant Pear as material. In theexperiment, we treated the plants in four levels, e.g.30kg each tree,50kg each tree,80kg each tree,100kgeach tree. And we treated the plants in three fruit load processing, for high, medium and low. The leaf netphotosynthetic rate, stomata conductance，intercellular CO2concentration, transpiration rate, chlorophyllcontent, starch content and chloroplast ultrastructure were observed under the treatments of different fruitloading capacity and different fertilization conditions. The main results are shown as following:1. The photosynthetic rate and starch content had been increased in different degrees with theincreasing of the fertilizer levels. In the experiment, it was found that besides10years-old and20years-oldplants, the chlorophyll content was higher than the others, and the fertilizer treatment was100kg each tree,the starch content was higher than the others, when the fertilizer treatment was80kg each tree. In10years-old Korla Fragrant Pear, the photosynthetic rate was highest with100kg each tree. In20years-oldKorla Fragrant Pear, the photosynthetic rate was highest with80kg each tree. The volume and quantity ofthe starch grain in leaf cells were increased with the increasing of the amount of fertilizer. When theamount of fertilizer reached a high level, it was resulted the reduction of the chlorophyll content and thephotosynthetic rate. From the experiment, the amount of fertilizer must be controlled in a right range withthe growth status of Korla Fragrant Pear.2. The results showed that the leaf photosynthetic rate, stomata conductance, transpiration rate andstarch content were bigger in high fruit loading capacity than in low fruit loading capacity in10years-oldand20years-old Korla Fragrant Pear. Both the quantity and volume of the chloroplast in high fruit loadingcapacity were higher than that in low fruit loading capacity under the conditions of high loading capacity ofthe fruit. So, the appropriate addition of loading capacity of Korla Fragrant Pear was conductive toimproving the leaf photosynthetic efficiency．...