杉木侧枝发育特征及其与内源激素的相关性.

The objectives of this study were to determine the differences in growth and developmental characteristics of the lateral branches of different Chinese fir strains and their correlation with endogenous hormones and to select Chinese fir strains suitable for the cultivation of knotless timber. Three-year-old Chinese fir of six different strains (Cunninghamia unicanaliculata, Chuizhisha, Yang 063, Hongxinsha, Yang 020, and Yang 061) were collected from a forest to serve as the research subjects. The developmental characteristics of the lateral branches of the different Chinese fir strains were investigated, and the endogenous hormone content of the lateral branches was measured. The results showed that the Chinese fir strains differed in under branch height, internode length of trunk (distance between two adjacent lateral branches), and number of lateral branches (number of lateral branches per round on the trunk). Among them, Yang 063 and Chuizhisha had the greatest under branch height; Chuizhisha and Yang 020 had the largest internode length; and Yang 020 and Yang 061 had the fewest lateral branches per round. The strains of Chinese fir also differed in the length, base diameter, and angle of lateral branches. The values of the lateral branch length and base diameter of the Chinese fir strains were ranked as follows: Yang 063＞ Yang 061＞ C. unicanaliculata＞ Hongxinsha＞ Yang 020＞ Chuizhisha; the values of the lateral branch angle of the Chinese fir strains were ranked as follows: Chuizhisha＞ Yang 020＞ Yang 061＞ Yang 063＞ Hongxinsha＞ C. unicanaliculata. Cytokinin, indoleacetic acid, and CCTK/CIAA contents in the lateral branches of the Chinese fir strains also differed; however, strigolactone was not detected in the lateral branches of Chinese fir. There were different degrees of correlation between the lateral branch growth indexes and endogenous hormone indexes of the different Chinese fir strains, endogenous hormones can affect the growth of lateral branches of plants, CTK promoted the growth of lateral branches of Chinese fir, and IAA inhibited the growth of lateral branches of Chinese fir, both of which have obvious antagonistic effects on the growth of lateral branches of Chinese fir. [ABSTRACT FROM AUTHOR]