Abstract:

Three-year-old saplings of ‘Lüling’ walnut (Juglans regia) from Hebei Lüling fruits Co. Ltd. were used to study effects of bending branch and notching bud in different periods on the budding rate, shoot growth and contents of endogenous hormone (GA₃, IAA,ABA and ZT). The results showed that the average budding rates for the branch bending angles of 45°, 90°,135° were 65.03%, 71.38%, 62.45%, respectively, and the budding rate with the bending angle at 90° was very significantly higher than that of bending angles at 45° and 135°. The average budding rates of notching bud treatment in March and April were 4.43% and 3.57% higher than that of non-notching bud treatment. The average shoot lengths with bending branch angles of 90° and 135° were decreased by 18.71% and 49.44% compared with that with bending angle at 45° in March. The average shoot lengths with notching bud and bending branch to 90° and 135° treatments were 46.93% and 60.45% lower than that of bending branch 45° in March. There was no significant difference in shoot lengths among every treatment treated in April. The proportions of young shoots at the base of branches with bending branch to 90° and 135° treatments in March were 22.76% higher than that of bending branch to 45° treatment. The upper buds of branches with bending angle 45° had the highest contents of GA₃, IAA and ZT, and the contents were very significantly higher than that of bending branch to 90°, which in turn were very significantly higher than that of bending branch to 135°. The content of ABA in the upper buds of bending branch to 135° was very significantly higher than that of bending branch to 45°and 90°, and that in the base buds was very significant lower than that of bending branch to 45°and 90°. The ratio of GA₃/ABA in the upper buds of bending branch to 45° was very significantly higher than that of bending branch to 135°, and that in the branch base buds was very significantly lower than that of bending branch to 135°. The ratios of ZT/IAA in the upper buds of bending branch to 135° was very significantly higher than that of bending branch to 45°and 90°. As for bending branch to 90° treatment, the contents of GA₃ in the upper and base buds with notching bud treatment were significantly lower than that of the non-notching, the contents of ABA in the all buds with notching treatment were significantly higher than those of the non-notching, the ratios of GA₃/ABA in the buds with notching treatment were significantly lower than those of the non-notching.

Key words: Juglans regia, bending branch, notching bud, budding rate, shoots, endogenous hormones