Influences Of Different Grafting Time’s Walnut Cuttings On Inclusion Variation And Survival Rate

The study materials came from 5-year-old hybrid early-fruiting walnut cuttings and 1-year-old stocks. Determination content included inclusions main physiological and biochemical indexes of cuttings and stocks during different grafting time (January, February, March and June), and survival rate of grafting. The data were used for correlation analysis between each inclusion and grafting. The aim of this article was to explore the best picking cuttings time and grafting time. The results as follows:(1) Dynamic variation of early-fruiting walnut cutting’s inclusions arranged high to low:water content stabled in winter and increased in summer, June (83.7%)> February (51.2%)> March (50.8%)> January (49.1%); tannin content decreased and then increased:January (1.62%)>June (1.26%)> February (1.09%)> March (0.87%); the protein content gradually increased and then tended to keep stable, March (0.023 mg/g) > June (0.022 mg/g)> February (0.012 mg/g)> January (0.01 mg/g); soluble sugar content increased and then decreased, February (8.75%)> January (7.89%)> March (6.76%)> June (5.51%); C/N went up and then cut down, March (410.9)> February (407.2)> January (337.4)> June (225.7); polyphenol content decreased and then rose up, June (2.78%)> January (2.39%)> February (2.00%)> March (1.61%); potassium content decreased and then rose up, June (10.97 mg/g)> January (1.56 mg/g) > February (0.96 mg/g)> March (0.84 mg/g); sodium content decreased and then rose up, January (0.85 mg/g)> June (0.61 mg/g)> February (0.44 mg/g)> March (0.26 mg/g); magnesium content increased and then decreased, March (0.26 mg/g)> February (0.21 mg/g)> January (0.15 mg/g)> June (0.13 mg/g)(2) Dynamic variation of stock’s inclusions arranged high to low:water content decreased and then increased, June (78.4%)> January (50.8%)> February (41.3%) > March (39.6%); tannin content decreased and then increased:January (0.79%)>June (0.71%)> February (0.35%)> March (0.21%); polyphenol content decreased and then rose up, June (1.42%%)> January (1.32%)> February (1.22%)> March (0.84%); the protein content gradually increased and then tended to keep stable, March (0.018 mg/g) > June (0.017 mg/g)> February (0.015 mg/g)> January (0.007 mg/g); soluble sugar content gradually decreased, January (16.12%)> February (13.89%)> March (13.24%)> June (6.32%); C/N went up and then cut down, March (677.0)> February (626.4)> January (415.0)> June (188.9); potassium content decreased and then rose up, June (9.89 mg/g)> January (3.39 mg/g)>February (3.37 mg/g)> March (2.99 mg/g); sodium content decreased and then rose up, January (0.48 mg/g)> June (0.27 mg/g)> February (0.22 mg/g)> March (0.15 mg/g); magnesium content increased and then decreased, March (0.28 mg/g)> February (0.24 mg/g)> January (0.17 mg/g)> June (0.11 mg/g).(3) Low temperature storage effect on early-fruiting walnut cutting’s inclusions: water content decreased from 49.1% to 48.0%, decreased by 1.1%; tannin content reduced from 1.62% to 0.56%, decline of 1.06%; polyphenol content decreased from 2.39% to 1.34%, decreased by 1.05%; soluble sugar content fell down from 7.89% to 2.82%, decline of 5.07%; sodium content decreased from 0.85 mg/g to 0.41 mg/g, decreased by 0.44 mg/g; protein content rose up from 0.010 mg/g to 0.019 mg/g, increased by 0.009 mg/g; C/N increased from 337.4 to 387.2, increased by 49.8; potassium content went up from 1.52 mg/g to 1.87 mg/g, increased by 0.31 mg/g, magnesium content rose up from 0.15 mg/g to 0.16 mg/g, increased by 0.01 mg/g.(4) The effect of each factor’s correlativity on graft survival rate:temperature and precipitation were positively correlated to graft survival rate, each correlation coefficient was 0.982, tannin and polyphenol content of early-fruiting walnut cuttings were negatively correlated to graft survival rate, correlation coefficient were-0.956 and -0.991 respectively, polypnenol content of stocks was negatively correlated to graft survival rate and the correlation coefficient was-0.997.(5) The contrast of graft survival rate in January, February and March ranged from high to low:March and refrigeration (65%)> March and fresh (56%)> February and fresh (34%)> January and fresh (23%). Hence, the optimum scion grafting time of walnut at Sichuan basin was March. The optimum picking time of cuttings was January and it is necessary to refrigerate until March.