Study On Growth,fruit Leaf Quality And Drought Resistanceof Different Clones Of Mulberry In Windy And Sandy Area Of Northwestern Liaoning

Morus spp.is an important economic tree species in China.Its leaves and fruits have important economic value.Due to the arid and cold climatic conditions in Northeast China,southern varieties are not suitable for planting in Northeast China.Therefore,it is urgent to screen out varieties suitable for local cultivation.A large area of wild Morus spp.trees is naturally distributed in the northeastern region.Through the investigation and selection of Morus spp.trees in the area,the Morus spp.trees suitable for planting and cultivation in the region are selected.The three excellent clones collected,‘Hong Luo Xian'(HLX),‘A Er Xiang'(AEX),‘Ji An'(JA)and the Morus spp.variety ‘Long Sang No.1'(LS)selected by the Heilongjiang Province,carried out research on growth,quality and drought resistance,and selected the best growing Morus spp.varieties that were most suitable for planting in northwestern Liaoning.The research conclusions are as follows:(1)Comparative analysis of the growth and photosynthetic characteristics of four Morus spp.clones,HLX and JA were excellent in growth characteristics.At the same time,the light and pigment content of the two clones were higher than those of AEX and LS,while the apparent quantum efficiency and maximum net photosynthetic rate of HLX and JA are significantly higher than AEX and LS.However,the light compensation point and dark respiration rate of LS were significantly lower than the other three clones,indicating that the LS performed better in low light conditions.From the photosynthetic-light response curve,it can also be concluded that the light and ability of the four clones are in order from the largest to the smallest is HLX,JA,AEX and LS.(2)Using the membership function to compare the leaf and fruit quality of the four Morus spp.clones,the leaf quality of the four clones Morus spp.are in order from the largest to the smallest is,HLX,LS,AEX and JA.The nutritional quality of the four clonal fruits is slightly different from that of the leaves.From high to low,it is AEX,HLX,JA,LS,comprehensive comparison,HLX has the most nutritional quality Excellent.(3)Comparative analysis of photosynthetic characteristics of four Morus spp.clones under drought stress,the change of photosynthetic pigment content of AEX is the least significant,second is LS,followed by JA and HLX.The photosynthetic pigment content of the ditch is significantly reduced.The decline in net photosynthetic rate of AEX,LS,JA and HLX increased in turn.(4)The comparative analysis of the response of the photosystems of four clonal Morus spp.trees after drought stress,the maximum photochemical efficiency(FV/FM)and potential photochemical activity(FV/FO)of Morus spp leaves after drought stress were studied in this study.The decline ranged from small to large,followed by AEX,LS,JA and HLX,and the VJ and MO of four clones rise in a similar pattern.Under the drought stress,the ABS/RC and TRo/RC of the PSII reaction center of the Morus spp.leaf showed an increasing trend,from high to low,AEX,LS,HLX and JA.DIo/RC of HLX,JA,AEX and LS values increased in turn.In summary,through analyze of the growth characteristics,quality and stress resistance of four clonal Morus spp.trees.When it's in normal,HLX has the largest growth,and the leaf and fruit nutritional quality are excellent.Planting HLX can achieve the highest economic benefits;when the ecological environment is relatively fragile,the rainfall is low or the land is relatively dry,the drought resistance of AEX is the best among the four clones.Planting AEX can ensure that the Morus spp.can be well in the arid and semi-arid environment of western Liaoning.Through a deeper and more systematic understanding of the biological characteristics of four clonal Morus spp.trees,it provides a powerful theoretical support for the future production and popularization of Morus spp.trees in northwestern Liaoning.