Effect Of EDTA Treatment On Anatomic Structure And Morphological Character Of Different Parts In Ziziphus Jujuba Mill.'Huping Zao' Fruit Cracking

Calcium is an indispensable nutrient element in the growth and development of jujube fruit,and also plays an important role in the prevention and control of jujube dehiscence.In this experiment,Ziziphus jujuba Mill.‘Huping zao'from Taigu County,Shanxi Province,was used as the test material.Ziziphus jujuba Mill.‘Huping zao'was sprayed with EDTA in different concentration of 0.001g·mL-1 and 0.00067g·mL-1 for 2 times,4 times and 6 times.The single fruit weight,fruit shape index,hardness and stomatal index of jujube fruit were measured.The anatomical structure of leaves and jujube fruit were observed by paraffin section.The best concentration and spraying times were obtained by combining the rate of cracking.The main conclusions were as follows:(1)The cracking rate was reduced by EDTA treatment with different concentrations and times,cracking rate of B3<A3<A2<B2<B 1<A1<CK.After the treatment of 0.00067g·mL-1 for 6times,the anti-cracking effect was the best and the cracking rate was the lowest,cracking rate was 13.71%,Compared with the control group,45.13%decreased by 31.42%.(2)Different concentration and spraying the EDTA after processing,the number of jujube fruit weight,fruit hardness than contrast were significant difference,EDTA treatment significantly greater than the control,after 0.00067g·mL-1 EDTA treatment 6 jujube fruit weight and maximum hardness,single fruit weight is 12.81g,an increase of 3.4g control,hardness of 14.66 kg·cm-2,an increase of 1.58kg·cm-2 contrast;Compared with the control group,the fruit shape index of EDTA was not significantly different from that of the control group.(3)There were significant differences in stomatal density,size,and opening of leaves after treatment with different concentrations and spray times.Compared with the control,the stomatal density,size,and opening degree of the leaves were significantly smaller than those of the control.After 0.67 mg·nL-1 EDTA treatment for 6 times,the stomatal density,size,and opening of the leaves reached the minimum,210.03p·mm-2,397.05?m2,156.91·?m2;The stomatal density,size and opening of the pericarp were significantly different from those of the control,both of which were greater than those of the control.The densities,sizes,and openings of the stomata reached the maximum after 6 treatments of 0.67mg·mL-1.It is 66.51 p.mm-2,683.21 ?m2,and 459.52 ?m2(4)Leaf microstructure:After treatment with EDTA,the epidermal thickness and upper epithelial cell size of the leaves were significantly different from those of the control group,which was significantly greater than that of the control group.After the treatment of 0.67mg·mL-1 EDTA 6 times,the upper epidermal thickness and upper epithelial cells reached the maximum,35.30?m and 615.24?m2,respectively.There was no significant difference in the thickness and cell size of the lower epidermis layer after treatment with EDTA.The thickness of palisade tissue after treatment with EDTA was significantly different from that of the control.Both were significantly larger than the control and 0.67 mg·mL-1 EDTA.The palisade tissue thickness reached a maximum of 73.60 ?m after 6 treatments.(5)The microstructure of jujube fruit:After spraying different concentrations and times of EDTA,there was no significant difference in the thickness of jujube cuticles between different treatments and control;the thickness of epidermis layer was significantly different from that of the control,which was greater than that of the control 0.67mg·mL-1 EDTA treatment 6 times The thickness of the posterior epidermal layer reached a maximum of 70.07 ?m,which was 18.53 ?m higher than that of the control.The epidermis cell size was significantly different from the control and was significantly smaller than that of the control.The epidermal cell size reached a minimum of 222.18 ?m2 after 0.67mg·mL-1 EDTA treatment 6 times,which was lower than the control,smaller 144.51 ?m2(6)The fruit cracking rate of jujube jujube was positively correlated with leaf stomatal density,leaf stomata size,leaf stomatal aperture,and fruit epidermis cell size.The correlation coefficients were 0.927,0.981,0.983,0.882,respectively,and fruit weight,fruit stomatal density,There were extremely significant negative correlations between stomatal opening,leaf epidermal cell size,leaf palisade tissue thickness,and fruit epidermis thickness.The correlation coefficients were-0.973,-0.942,-0.978,-0.948,-0.979,and-0.919.