Effects of gibberellin A_（4/7）, 6-benzylaminopurine and chlormequat chloride on the number of male and female strobili and immature cones in Chinese Pine （Pinus tabuliformis） with foliar sprays

• Published in: 林业研究：英文版 2011, Vol.22 (3), p.353-359
• Main Author: ZHAO Peng Keith E. Woeste ZHANG Shuo-xin YANG Peihua FAN Jun-feng HUANG Zhong-lian MA Zhen-hua
• Format: Article
• Language: English
• Subjects: 叶面喷洒; 女性; 成熟; 氯化; 油松; 男性; 矮壮素; 苄氨基嘌呤
• ISSN: 1007-662X; 1993-0607

Three kinds of plant growth regulators, gibberellinA 4/7 （GA 4/7 ）, 6-benzylaminopurine （BA）, and chlormequat chloride （CCC）, were evaluated for their ability to promote strobilus and cone production in a Chinese pine （Pinus tabuliformis Carr.） clonal seed orchard. Treatments （0, 250, 500, or 1000 mg L -1 ） were applied during three periods （June- July, July-August and August-September） in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed with GA 4/7 （500 mg L -1 ） from June to September had significantly more female strobili and immature cones than controls and other treatments （p≤0.0001）. The best time to apply GA 4/7 was in June. BA at 500 mg L -1 significantly increased female flower and immature cone production, compared to other treatments and controls （p≤0.0001）, while promotion of male strobili was unchanged. Chlormequat chloride at 1000 mg L -1 significantly increased the number of male strobili, compared to the other treatments （p≤0.0001）. Spraying CCC at500 mg L -1 significantly increased the number of female strobili, compared to controls （p0.05）, but it had no effect on immature cone production （p0.05）. These results are important for improving seed production and seed orchard management of Chinese pine.