Effects Of High Concentration 6-BA On Walnut Fruit And Fatty Acids

Juglans regia is a walnut plant belonging to the family Juglansaceae.It is one of the four major nut species in the world and is widely planted all over the world.Walnut kernel is rich in oil,protein,mineral elements,vitamins and a variety of bioactive components beneficial to human body.China’s walnut production and planting area has ranked first in the world for many years.In recent years,China’s Walnut planting area is about 100 million acres and the output has reached 4 million tons.China’s edible oil is excessively dependent on imports.The use of walnuts in vegetable oil processing can effectively alleviate the adverse situation of low self-sufficiency rate of edible oil in China.In order to explore the effects of 6-BA on walnut fruit and walnut kernel oil,based on the research of low concentration treatment in the early stage,high concentration 6-BA treatment was further used.20 indexes such as weight and shape of walnut fruit,oil content of walnut kernel and fatty acid composition were measured,and the differences were analyzed by significance test;In order to eliminate the error of field experiment,correlation analysis,cluster analysis and principal component analysis are used to improve the reliability of difference analysis results.The main results are as follows.(1)Effects of high concentration 6-BA on Walnut weight and three diametersHigh concentration of 6-BA had an overall inhibitory effect on the weight and morphology of walnut fruit,and the inhibitory effect on the longitudinal diameter,transverse diameter and lateral diameter of green fruit reached a significant level on the 28 th day;The inhibition effect on the weight,longitudinal diameter and lateral diameter of drupe showed the law of significant inhibition in the early stage,weakening in the middle stage and gradually disappearing in the later stage.6-BA treatment increased the specific gravity of nuts,and the specific gravity of nuts increased by 6.64% after 7 days of 400 mg/L 6-BA treatment.(2)Effects of high concentration 6-BA treatment on fruit shape index of walnutHigh concentration 6-BA treatment reduced the walnut fruit shape index as a whole and made the walnut fruit shape more spherical.After 6-BA treatment,the decline of green fruit shape index increased with the increase of concentration and decreased with the increase of time.There was a significant negative correlation between green fruit shape index and green fruit transverse diameter,and there was a significant negative correlation between drupe shape index and green fruit transverse diameter and drupe transverse diameter.This result was consistent with the effect of 6-BA on walnut fruit shape index.The D value difference of phenotypic clustering was consistent with the overall inhibitory effect of 6-BA on walnut fruit.The D values of 100,200 and 400 mg/L treatments were 0.02,0.05 and 0.04 lower than the control,respectively.In the results of phenotypic principal component analysis,the loading direction of three concentrations of 6-BA on walnut fruit shape index was opposite to that of the control group,which was consistent with the result that 6-BA treatment could reduce walnut fruit shape index.(3)Effects of high concentration 6-BA treatment on oil content and fatty acid composition of walnut kernelThe effect of high concentration 6-BA treatment on the oil content of walnut kernel was not obvious,but it had a great impact on the fatty acid components,showing the law of significant in the early stage,gradually disappearing in the middle stage and returning to the normal level in the later stage.Among them,the relative content of stearic acid increased significantly(24.59%)on the 7th day after 100 mg/L 6-BA treatment,the relative content of saturated fatty acid increased significantly(3.46%)and the relative content of unsaturated fatty acid decreased significantly(4.62%)on the 1st day after 200 mg/L 6-BA treatment,the relative content of palmitic acid increased significantly(21.72%)on the 7th day after treatment,and the relative content of oleic acid decreased significantly(22.39%)on the 1st day after 400 mg/L 6-BA treatment,The relative content of linoleic acid increased in the same period(8.52%).(4)Multivariate statistical analysis on the difference between oil content and fatty acid composition of walnut kernelIn the correlation analysis between walnut oil content and fatty acid components,stearic acid and oleic acid had a significant positive correlation after high concentration 6-BA treatment.The D value difference of walnut kernel oil content and fatty acid component clustering is consistent with the significant effect of 6-BA on walnut kernel fatty acid component in the early stage.In the results of principal component analysis,the absolute values of the three concentration sample points in the mature stage are the largest in the direction of oil content,which is consistent with the results of the effect of 6-BA treatment on oil content.In summary,high concentration 6-BA treatment will significantly affect walnut fruit weight,stone fruit shape,walnut kernel proportion and fatty acid composition in a short time.According to the production needs of fresh walnuts,low oleic acid walnuts and high linoleic acid walnuts,6-BA with different concentrations can be selected for treatment and harvested in an appropriate time.The results of this study provide a scientific basis and new insights for the Directional Cultivation and utilization of walnut.