| Experiments were carried out to study the effect of stem-girdling and exogenous hormones injection (GA3, GA4/7 and BAP) on the stem physiology, photosynthetic capacity and metabolites of soluble sugars, tannins, flavonoids, soluble protein in leaves of Korean pines. Results are the following:Short term treatment of stem girlding of Korean pine(4 week) did not abruptly change the carbohydrates status both at the upper and lower parts of girdling stem, particullarly in the case of starch content. This may be realted with their respiratory consumption. Moreover, girdling treatment strongly affect the linear correlation of soluble sugar contents between xylem woods and pholem barks.The content of fructose, glucose and sucrose existed mutual correlations and these correlations at the lower parts were more evident than at the upper parts.Girdling treatment differently affected soluble sugars and the effect to fructose and sucrose was stronger.Girdling treatments down regulated the leaf photosynthetic rate of different ages. the down-regulation of main stem girdling and girdling at grade-one branches was quite similar.However, girdling at grade-two branches affected the photosynthetic rate of needles more quickly. This finding indicates that girdling makes the photosynthates from current-year needles come down,, while those from 1-yr-old needles become the main strength of the photo.synthesis.Judging from average value, from 10 days to 50 days after injection, the stem respiration of trees injected GA4/7 inproved obviously, while control and the trees injected GA3andBAP were raising slowly.The stem respiration are not different in different kinds of hormonesDifferent age needles' photosynthetic rate changed differently after the hormone injection at adut trees. Compared with control, 1-yr-old needles averagely improved 4.57%, while current-year needles and 2-yr-old needles averagely declined 10.91% and 2.68%, respectively. Hormone pasting at different branch or stem functioned differently on the leaf photosynthesis of young trees. The photosynthetic rate of current-year needles and 1-yr-old needles of theKorean pine were higher than control in the case of hormone pasting on the main stem, whilethey were lower than control in the case of hormone pasting on small branches. However, thephotosynthetic rate of 2 -yr-old needles higher than the control in both cases.50 days after injection, both GA3 and GA4/7 strongly declined the tannins content in current-year leaves (in average 30%) compared with control, while BAP treatment only declined 10%。All three hormone trements gave no effect on the flavonoids content with respecting to control. Averagely, about 30% decline in the soluble protein content was observed in both BAP and GA4/7 injection, while no such obvious decline was observed in GA3 ??treatment.The injection of GA3 and GA4/7 strongly affect the bud formation, but no influences were found in BAP injection comparing with control. The top bud numbers of the trees injecting GA4/7 are more than control, especially GA4/7(240mg) which inproved 33.33%. The lateral bud numbers of branches of injecting different hormones are less than control except GA3, which inproved 2.37% in average. GA3 (60mg) strongly improved 36%, and GA3(30mg) and GA3(120mg) declined the lateral bud numbers with respecting to control.The number of cones was different in different hormones inection: BAP＞GA3＞GA4/7＞control. Middle and low concentration of GA3 slight changed the number of cones, while high concentration GA3 inproved 261.5%. Injection of middle and low concentration of GA4/7 could improve the number and high concentration reduced the number. Injection of BAP at different concentration could improve the number of cones 79.49 % in average.
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