Photosynthetic Characteristics Of Two Macthing Cultivars Of Common Walnut Main Planting In The Southern Xinjiang Basin

Walnut(Juglans regia L.)was the second largest economical forest planted species in South Xinjiang basin,the "Wen185"(J regia 'wen185')and the "Xinxin2"(J regia 'xinxin2')is two matching cultivars of common walnut main planting.The photosynthetic characteristics of the southern Xinjiang basin under high light and heat environment was studied,it is not only helpful for the cultivation and management of walnut production garden,but also can provide scientific basis for breeding new walnut varieties which are suitable for the high light and heat conditions in the southern Xinjiang Basin.In view of this,In this paper,under the planting environment of Wushi County in the southern Xinjiang basin,the"Xinxin2"and the "Wen 185" are taken as the object of study,with the aid of a photosynthesis tester and a fluorescence analyzer,The method of live determination was adopted,the photosynthetic characteristics of two walnut varieties were compared in different phenological period(fruit setting period,fruit rapid growth period,fruit hard core period,fruit fat change period and fruit near-mature period),a comparative analysis of two under sunny and cloudy weather conditions in leaves of walnut cultivars at different phenological period of fruit development,the net photosynthetic rate(Pn)conversion efficiency of light energy in the growth period of two varieties of walnut fruit under sunny weather conditions and characteristics(Fv/Fm)characteristics.The main results showed that:The mathematical model suitable for fitting the light response curve of two walnut varieties is the right angle hyperbola correction model.The "Wen185" fruit walnut varieties in different growth period of the highest light saturation point in the fruit near-mature period(1 492 ?mol·m-2 s-1),rapid growth period of the lowest(1 332 ?mol·m-2·s-1),the light compensation point of fat changes period was the highest(52?mol·m-2`s-1),fruit hard core period was the lowest period(36 ?mol·m-2·s-1)."Xinxin2" walnut fruit period of light saturation point fruit fat change period was the highest(1552 ?mol·m-2·s-1),the lowest was fruit hard core period(1 216 ?mol·m-2·s-1),the light compensation point of hard core period was the highest(64?mol·m-2·s-1),lowest fruiting period was fruit setting period(32 ?mol·m-2·s-1).High light and heat conditions of two walnut varieties of South Xinjiang basin did not have a good ability to adapt.Sunny,cloudy and two kinds of weather conditions,two varieties of walnut fruit canopy at different development stages of different parts of the leaf blade Pn diurnal variation and different parts of the leaf blade in the fruit Pn change there are significant differences in the different growth period.The curve of peach varieties in different growth period of fruit kernel canopy leaf Pn diurnal variation of south direction two under sunny weather conditions with double peaks appeared,caused by the stomatal limitation was the phenomenon of midday depression of photosynthesis;cloudy weather conditions,two varieties of walnut fruit in different growth period of canopy South leaf Pn diurnal variation curve showed a single peak,without the occurrence of the phenomenon of midday depression of photosynthesis;two under two kinds of weather conditions of walnut leaves in a canopy cellae fruit at different growth stages,Pn has always been in the lowest level.Sunny and cloudy weather conditions,two walnut products The change trend of Pn in different stages of the same kind of fruit,but do not overlap,there are significant differences,and the"Wen185" net photosynthetic rate was higher than that of the "Xinxin2";cloudy weather conditions,two different varieties of walnut fruit at different growth stages,the trend of Pn,present cross state,and there are significant differences."Wen185" and "Xinxin2" crown of walnut varieties in different growth period of fruit of different part leaves the light conversion efficiency(Fv/Fm)and diurnal variation of different part of leaves showed significant differences in Fv/Fm changes of fruit in different growth stages.The periphery of the crown is south to the leaves of diurnal variation of Fv/Fm was decreased the increasing trend of "V";The Fv/Fm of canopy leaves in South fruit at different growth stages,is always lower than that of the other four birth place.At the same time,two different varieties in different growth stages of fruit Fv/Fm change trend,present cross state,there are significant differences,but with the overall fruit growth period goes on the upward trend.