Study On Comparation Of Photosynthetic Fluorescence Characteristics And Yield Quality Between Early And Late Fruiting Walnut Varieties

The experimental materials of this study were the three early fruiting(‘Qiangtele',‘Xiangling'and‘Zhonglin3#')and three late fruiting(‘Jinlong1#',‘Jinlong2#' and ‘Qingxiang')walnut varieties.By using Li-6400 portable photosynthesis system and PAM-2500 portable chlorophyll fluorescence system determined the photosynthetic and fluorescence parameters and analyzed the dynamic change rule and difference of photosynthetic fluorescence parameters,yield and quality of early and late walnut varieties.The purpose is to find the relationship between photosynthetic fluorescence parameters and yield and quality,aiming to provide theoretical basis for high-yield cultivation under its production conditions.The main results are as follows:(1)4-8 months,the same photosynthetic parameters' diurnal variation of early and late walnut are the same basically,and the diurnal variation of Pn of most walnut varieties showed a double-peak curve and had obvious midday depression phenomenon,and this phenomenon is caused by the dual role of stomatal and non stomatal factors;(2)The early fruiting walnut varieties' diurnal variation rule of Tr,Gs and Ci are similar to late walnut fruiting varieties,and the diurnal variation of WUE is different quitely,and have great fluctuation in 6,7 and 8 mouths;Except for April,the mean values of daily change of Pn in late fruiting walnut was greater than that of early fruiting walnut,which indicated that the late fruiting walnut has stronger photosynthetic capacity;(3)The diurnal variation of fluorescence parameters of early fruiting walnut is similar to late fruiting walnut.The early fruiting walnut is more sensitive to light inhibition,and the ability of self-protection of photosynthetic mechanism was strong;Late fruiting walnut has stronger use to strong light and environmental adaptability.Compared with early fruiting walnut,late fruiting walnut has stronger light requirement;(4)The yield per plant of early fruiting walnut is higher than that of late fruitingwalnut,and the single fruit weight is significantly lower than that of late fruiting walnut.The content of SS,SP and CF of late fruiting walnut is significantly higher than that of early fruiting walnut.The kernel rate of early fruiting walnut is lower than that of early walnut,but the difference is not significant;(5)Early and late fruiting walnuts' yield per plant and Pn were significantly positively correlated;SS,SP and Pn have significant correlation,and Gs,Ci,Fv/Fm and qN have a positive correlation;Early fruiting walnut and Pn,CF,Tr and Gs have a certain degree of negative correlation,CF and Pn,Tr and Gs have a positive correlation of late fruiting walnut.