The Study Of Photosynthesis Characters Of Apples From The North Of Wei

This study was carried from 2005 to 2006 in Fengxiang Shannxi with Royal Gala, American Eight, LiQuan Fuji and Fuji Two apples. Their photosynthesis characters were measured by the LI-6200 portable photosynthesis machine. It includes the monthly variation of Pn and diurnal variation; the influence of the PAR and CO2 to the Photosynthesis and the difference of Pn between the varieties and the branches and leaves locations. The purpose is to study the Photosynthesis characters of the apples in the north of Wei and provide the basis of rising the quality of the apples.The main results were as follows:1.The difference of the monthly variation between different varieties. Liquan Fuji and Fuji Two's monthly variation of Pn is a double peak curve, it's peak is in June and August;Royal Gala and American Eight's monthly variation of Pn is a single peak curve, it's peak is in June. Royal Gala and American Eight's Pn is higher the Liquan Fuji and Fuji Two in June and July, but lower in later August. The reason is that American Eight and Royal Gala are harvested after August, their power of the storage is weaken.2.The difference of the diurnal variation between different varieties. The diurnalvariation of American Eight, Royal Gala, Fuji Two and Liquan Fuji are all double peak curve in July on the fine day, the peak is on 11 and 15,but is a single peak curve on the somber day and nubilous day and the peak in on 13.The Pn on the fine day is better than the somber day and the nubilous day. There is no difference among American Eight, Royal Gala and Liquan Fuji in July, all better than Fuji Two.The diurnal variation of American Eight and Liquan Fuji is single peak cure in September and both obviously lower than the Pn in July. American's Pn has a obvious decline in September, it only is the 52.65 percent of the July's Pn. Liquan Fuji's Pn on September in the 83.39 of the July's.3.The effect of some factors on the photosynthesis characters. In a certain range, the Pn of the leaves is raise as the increase of the light intensity and CO2 concentrations. LiquanFuji's light saturation point and light compensation point is 929.9μmol·m -2·s-1and23.7μmol·m -2·s-1 .the CO2 saturation point and compensation point is 800μmol·mol-1 and 150μmol·mol-1.The Gs of the leaves is increased with the increase of the light intensity and is a increased and then decreased again upward trend with the decrease of CO2 intensity. Among the five kinds of branches of the Liquan Fuji, the Pn of the leafage branch is the best and the short branch a little lower, the Long Branch and the healthy branch is in the middle, the middle branch is worst. In the different position of the crown, the best position is the south, the worst the north. The east is better than the west on 9-10.Among the leave position of the healthy branch,the best is the middle and the worst is the top,it is only the 33.48 percent of the best leaves.