The Research On The Rooting Mechanism And Cutting Orchard Management Of Pinus Serotina

Pinus serotina is native to the United States,and China began to introduce as charcoal forest in the 1960 s.On the one hand,It is more difficult to take seed,but it has strong sprouting ability and provides good conditions for cutting propagation.The study of Pinus cutting propagation attracted much attention and achieved certain results.However,there are few studies on the rooting mechanism and management of the cutting orchard.In this paper,the rooting mechanism and the management of cutting orchard of Pinus were studied.The results are as follows:(1)The relationship of content of nutrient and endogenous hormones under different seed-tree age and it’s cutting rooting.The seed-tree age were significant differences in rooting rate,the rooting rate from the largest to the smallest was two-year seeding(77.07%)>ten-year tree(40.42%)>Taihe 25-year tree(31%).Further analysis of nutrients content and endogenous hormone levels from cuttings of different seed-tree age shows that the content of nitrogen,soluble sugar,and the ratio of C/N were positively correlated with rooting,the correlation coefficients were 0.874、0.938、0.948,respectively.This shows that the content of soluble sugar,nitrogen and C/N ratio can be used to express the rooting ability.The younger seed-tree have higher cutting nutrient content and higher rooting rate.The content of IAA,ZR,GA3 and ratio of IAA/ABA and IAA/ZR were positively correlated with rooting rate of cuttings,the correlation coefficients were 0.911、0.894、0.790、0.937、0.918,respectively,there were significant correlation with rooting rate.The content of ABA was not significant correlation with rooting rate.From the experimental results,The were closely relationship of content of nutrient and endogenous hormones under different seed-tree age and it’s cutting rooting.(2)The relationship of content of nutrient and endogenous hormones under different maturity levels of twig and it’s cutting rooting.The different maturity levels of twig were significant differences in rooting rate,the rooting rate from the largest to the smallest was only have newborn leaves(75.70%)>The second leaf has just sprouted(61.64%)>Secondary leaf clusters have been opened,needles 1 cm long(51.24%).Further analysis of nutrients content and endogenous hormone levels from cuttings of different maturity levels of twig shows that the content soluble sugar and ratio of C/N were not correlated with rooting rate,the correlation coefficients were 0.521、0.422、0.350,respectively.This shows that only use the content of soluble sugar,nitrogen and C/N ratio to express the rooting ability was not ideal.The content of IAA,ABA,GA3 and ratio of IAA/ABA and IAA/ZR were positively correlated with rooting rate,the correlation coefficients were 0.852、0.858、0.818、0.945、908,respectively,there were significant correlation with rooting rate.The content of ZR was not significant correlation with rooting rate.From the experimental results,use the twig only that has newborn leaves can obtain higher rooting rate.There were closely relationship of content of nutrient and endogenous hormones under different maturity levels of twig and it’s cutting rooting.(3)The relationship of content of nutrient and endogenous hormones under different cutting season and it’s cutting rooting.Different cutting seasons had extremely significant differences in rooting rate of cuttings,the rooting rate from the largest to the smallest was May(77.07%)>July(43.02%)>September(15.98%)From the cutting results,we can see that the cutting is an important factor affecting the rooting.The content of soluble sugar and nitrogen,ratio of C/N were not correlated with rooting,the correlation coefficients were 0.670、0.423、0.795,This shows that only use the content of soluble sugar,nitrogen and C/N ratio to express the rooting ability of different cutting season y was not ideal.The content of IAA,ABA,GA3 and ratio of IAA/ABA and IAA/ZR were positive correlation with rooting rate,the correlation coefficients were 0.865、0.869、0.853、0.987、0.901,respectively,there were significant correlation with rooting rate.The content of ZR has no correlation with rooting rate.From the experimental results,cutting can obtain higher rooting rate in May.It was closely relationship of content of endogenous hormones under different cutting season and it’s cutting rooting.(4)The effect of budding quantity and twig quantity under different fertilization cycle and heading heightThe fertilization cycles and heading height of Pinus serotina have extremely significant differences in budding quantity and twig quantity.The treatment M1H3(fertilization cycles 15 days each time,heading height 15cm)was best,the average of budding quantity and twig quantity were 135.23,13.40,the treatment M2H3(fertilization cycles 30 days each time,heading height 15cm)was second,its average of budding quantity and twig quantity were 128.5,13.07.(5)The effect of budding quantity and twig quantity under different management measures of fertilizationThe fertilization cycles have extremely significant differences in quantity of budding and twig,the amount of fertilizer have no extremely significant differences in quantity of budding and twig,the fertilization model have extremely significant differences in quantity of budding and twig.Combined quantity of budding and twig,the treatment A1B1C2(fertilization cycles 15 days each time,amount of fertilizer was 5g,fertilization model was liquid fertilizer)was best,its average of budding quantity and twig quantity were153.10,18.