Dynamic Analysis Of Needle C And N,NSC And Terminal Bud Hormones In Pinus Koraiensis Trees With Different Seed Setting Situations

In this study,the annual scale continuous observation of terminal bud hormone,needle nutrient elements and non-structure carbon hydrate(NSC)of Pinus koraiensis individuals with different seed setting characteristics was carried out to explore the differences of gibberellin(GA),abscisic acid(ABA)and indoleacetic acid(IAA),as well as the content of carbon,nitrogen and NSC in needles in different temporal changes and spatial structures,The main results were as follows:(1)Different seed setting characteristics of Pinus koraiensis had obvious seasonal variation patterns.The variation patterns were opposite from August to October,and the variation trend was basically the same in other months.During the whole observation period,GA,ABA and IAA fluctuated,but the overall performance was increased.Compared with Pinus koraiensis with different seed setting characteristics,GA content was higher in March,may,August and September,ABA was higher in June,July and September,and IAA was higher in March,April,July and September.Under the spatial structure,the hormone content will increase with the increase of crown position,the content in south direction needles was greater than that in north direction needle,and the content of three hormones in stand edge was higher than that inside of stand.(2)The carbon,nitrogen and ratio of Pinus koraiensis needles with different seed setting characteristics changed differently.During the whole observation period,the content of carbon and nitrogen decreased and increased,and the carbon nitrogen ratio decreased and increased.The content of carbon was higher in April,may,June and September,and the content of nitrogen was higher in April,may,June and September.The ratio of carbon to nitrogen was higher in April,June and September.In June,July,August,September and November,the nitrogen content was higher in the current year’s needles,the carbon content appeared in March,June,July and November,and the carbon nitrogen ratio was March,April and May.Under the spatial structure,the content of carbon and nitrogen and the ratio of carbon to nitrogen in the upper crown were greater than that in the lower crown,the content of carbon and the ratio of carbon to nitrogen are greater in the south needle,the content of nitrogen was greater in the north needle,the content of carbon and nitrogen inside stand was greater than that in stand edge,and the ratio of carbon to nitrogen was opposite.(3)The trend of non structural carbohydrates in needles of Pinus koraiensis with different seed setting characteristics was basically the same with the season.The soluble sugar showed an increase and decrease,the starch showed an increase and decrease,and the NSC content showed an increase and decrease.Soluble sugar showed that seed setting was greater than non seed setting in the whole observation period,and starch showed that non seed setting was greater than seed setting in the whole observation period.The content of NSC was higher in March and July,and higher in other months.The contents of soluble sugar,starch and NSC in one year old were higher than those in one year old,whether fruiting or not.In terms of spatial structure,the contents of soluble sugar and NSC increased with the increase of canopy,and the south direction was greater than the north direction.Due to the difference of seed setting,the starch content was higher in the lower canopy,but higher in the upper canopy and higher in the south direction.Compared with the forest edge,starch and NSC showed that in stand edge was smaller than that inside stand,and the soluble sugar was larger in the stand edge.To sum up,the top bud hormone of Pinus koraiensis with different seed setting characteristics gradually increases with time,but the change trend of growth season is different due to the difference of seed setting.Under the conditions of high canopy,south direction and open forest edge,it shows higher content.The hormone content will be affected by the light environment,and has different effects on the seed setting process.During the growth observation period,the contents of nutrient elements and non structural carbohydrates of the two seed setting characteristics of Pinus koraiensis fluctuate,and there will be significant differences during the fruit development period.The spatial structure will also have an impact on different seed setting characteristics of Pinus koraiensis,that is,the light conditions are good,and the carbon and nitrogen content and NSC with appropriate concentration will promote the seed setting of Pinus koraiensis.