| The establishment of Cunninghamia lanceolata cutting orchard is to produce a large number of high-quality cuttings to accelerate the afforestation of Cunninghamia lanceolata.But there are different market demand for cuttings in different seasons.Because of the strong germination ability of Cunninghamia lanceolata and the actual requirements of the time of Chinese fir afforestation,the cuttings that have been in a state of germination and in the unsuitable season are not suitable for planting after cutting propagation.The overquick and excessive germination of the cuttings will result in a large amount of consumption of the body of the parent plant,which leads to the waste of the cuttings and the premature aging of the parent tree.Therefore,this paper selects the mother tree of the fine Cunninghamia lanceolata in Jianou Zhongfu company of Fujian Province as the research object.On the basis of studying the seasonal germination rule of the root of the parent tree,the treatments of different levels of shading,covering soil,spraying exogenous hormones and dropping Hoagland nutrient solution on the roots of Chinese fir were conducted.The quantity,quality,physiological index and rooting rate of the root of the parent tree were measured and analyzed for one year in order to explore the management measures to regulate the quantity and quality of the roots of Chinese fir,and to provide the theoretical and practical basis for the efficient management of the Cunninghamia lanceolata.The main research results have been obtained:(1)The seasonal germination and growth rule of the root of Chinese fir cuttings parent tree are as follows:the number of cuttings of the mother tree is 0 from January to February.A small number of cuttings appeared from March,cuttings was sprouting rapidly,reaching the peak of spike number in April,and then decreasing to June,it reached the small peak in the second half of the year in August,October and November.The coarseness of cuttings reached the maximum in March,April and June.In July and October,the biomass of cuttings was significantly higher than that of other months.In June and September,it was higher.The total N content of cuttings first descended to July,then increased to September and then decreased and then increased.The total P content increased first to July,then decreased to October.The total C content decreased to July,and then decreased to July and then rose.The activity of SOD in the cuttings tissue began to rise from April to July,and then decreased slightly to August,increased slightly to September and then steadily decreased.The activity of POD showed a rising trend from April to July,then decreased to October and then rose.The content of MDA showed a decreasing trend from April to July,increased slightly to October,and rose rapidly.(2)The regulation effects of different measures on the growth of Chinese fir cuttings were shown as follows:At the peak period of cuttings demand of Chinese fir,in April and May,the cuttings number and the coarseness of shading 75%were significantly higher than that of full illumination,but the biomass decreased with the decrease of the light intensity.The effect of soil covering measures on the number of cuttings was reduced,The tassel coarseness of that the thickness of covering soil is 5cm was obviously increased.The cuttings number of spraying 200mg·L-1 auxin solution was always higher than that of water treatment.The cuttings coarseness was larger than the control since June,and the biomass was greater than that of the control,but there was no significant difference;The cuttings number of spraying 10mg·L-1 abscisic acid solution was always lower than that of water treatment.The coarseness and biomass of cuttings was not significantly inhibited.The cuttings number of dripping irrigation two kinds of concentration of nutrient solution was improved,while the effect of Hoagland complete nutrient solution in drip irrigation was lasting.The cuttings coarseness was reduced,and the biomass and rooting rate had no significant effect.In addition to spraying abscisic acid solution,the rooting rate of cuttings was inhibited.Other measures had no significant effect on rooting rate.To some extent,combined treatment had an effect promoting sprouting on Chinese fir roots and had no significant effect on rooting rate.(3)The regulation effects of different measures on the contents of N,P,C of Chinese fir cuttings were shown as follows:The total N content of the cuttings of shading 75%was significantly higher than that of full illumination from April to July;The total P content increased with the decrease of light intensity;The total C content decreased with the decrease of light intensity.The total N and P contents of cuttings of covering soil did not increase significantly,but the total C content decreased significantly in May,August,September and December.The total N content of cuttings of spraying auxin and abscisic acid solution was obviously promoted from April to July.The total P content of the cuttings of spraying auxin solutionwas higher than that of spraying abscisic acid solution,but the difference was not obvious.In July and August,the total C content of the cuttings of spraying abscisic acid solution was higher than that of water treatment,but the total C content of the cuttings of spraying auxin solution was lower than that of the control.The total N content decreased with the increase of nutrient solution concentration;From April to July,the total P content of the cuttings was higher than that of the control,and the total P content of the cuttings was lower than that of the control.The total P content of both was higher than the control From October to December.The total N content of the combined measures showed an upward trend,and the total P content decreased firstly and then increased to November,and the total content was higher than that of the control,while the total C content showed a downward trend.(4)The regulation effects of different measures on the physiological characteristics of Chinese fir cuttings were shown as follows:The activity of SOD in the cuttings tissue increased first and then decreased,and the activity of POD increased first,then decreased and then increased,while the content of MDA decreased first and then increased.The activity of SOD between different shading treatments showed shading 75%>full illumination>shading 50%.The activity of POD of shading 50%was stronger than that of full illumination from April to August;The content of MDA showed shading 50%>full illumination>shading 75%.The activity of SOD increased significantly by the soil covering measures and MDA content was significantly lower than that of no covering soil.The activity of SOD treated with auxin was significantly weaker than htat of water treatment from June to October,while the activity of POD was not significantly different from that in water treatment from May to November,and the content of MDA was higher than that of water treatment.The SOD activity sprayed with abscisic acid was not significantly affected except for October,and the activity of POD was significantly stronger than in water treatment in April and December,and the content of MDA was significantly higher than in clear water treatment in August and December.The SOD activity of the two concentration nutrient solution was significantly higher than that of water treatment,and the activity of POD(except December)was lower than that of water treatment,and the content of MDA(except December)was significantly lower than that of water treatment.The activities of SOD and POD in combined treatment were stronger than those in control.(5)In summary,the optimal management scheme for the demand and non demand period of Chinese fir cuttings can be obtained through the analysis of the different measures and regulation mechanism of the root of the Chinese fir.From April to mid-June and July to September,the peak demand of Chinese fir cuttings,the shading net should be put on after overall scavenging cuttings in December of last year,in order to promote the germination.It is necessary to spray 200mg·L-1 auxin solution or apply Hoagland nutrient solution to the roots before May.In May,continuing to exert Hoagland nutrient solution to maintain the height production of the cuttings.For the suppression measures,from October to December in the non demand period of the cuttings,it can take 5 to 15cm thick soil and spray abscisic acid solution to inhibit its growth.The possibility of seasonal germination of the root of Chinese fir cuttings parent tree by artificial regulation is realized,which provides a scientific method for improving the proportion of seasonal afforestation in the south of Chinese fir plantation and the efficient and rational utilization of Chinese fir cutting orchard. |
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