| Phoebe bournei Hemsl.Yang,Lauraceae and Phoebe are evergreen trees in landscape.Phoebe bournei is a precious timber tree native to subtropical areas of China.Its trunk is tall and straight,and it is often used as a pillar in ancient wooden buildings.At present,Phoebe bournei is widely used as the national class II precious tree species.It is the timber raw material of the top-grade buildings,high-grade furniture,ships and so on.The shortage of market supply leads to serious losses of wild Phoebe bournei species.Therefore,artificial cultivation is needed to solve the market demand which is in short supply and realize the ecological protection of wild resources.The economic value of Phoebe bournei is very high.Researchers at home and abroad focus on the research and development of Phoebe bournei tree species.At present,the research on Phoebe bournei has made some progress,but it still needs deeper research and development and utilization.This study was conducted in Zhejiang Province.Six local plants suitable for the growth and development of Phoebe bournei were selected as experimental materials(Pingyang population,Songxi population,Songyang population,Xianliang population,Zhenghe population and Wuyuan population,respectively).In this experiment,the same reproductive techniques(soil type,planting method,conservation management and natural conditions)were used to determine and compare the growth characteristics,biomass and photosynthetic characteristics of Phoebe bournei from six different populations.The most representative population sites and high quality populations suitable for the growth of Phoebe bournei were screened out,which provided theoretical basis for the artificial cultivation and planting management of Phoebe bournei in Zhejiang area in the future,and provided reference for the selection of high quality population sites of Phoebe bournei.The main results are as follows:(1)The differences of 1000-grain weight,drainage volume and particle size among six populations were analyzed:The 1000-grain weight of Pingyang population was the most prominent,reaching 291.37g.The average length of seeds in Zhenghe population was 13.82 mm;the drainage volume of 100 seeds in Pingyang population was 23.06cm3;the average length of seeds in Zhenghe population was 13.82 mm among different populations,and the above three results were significantly different from those of other populations.(2)Through the comparative study of germination rate and germination potential of different populations of Phoebe bournei,the results showed that there were significant differences in germination potential and germination rate among different populations.The germination rate and germination potential of seeds in Pingyang population were the highest,which were 110.4%and 88.23%respectively.The results showed that the germination characteristics of seeds were significantly affected by environmental factors.(3)The seedling growth characteristics of six different populations were studied.The results showed that:?The plant height and ground diameter of six populations of Phoebe bournei(annual)were measured and recorded respectively.The results showed that plant height was significantly different among different populations,with Songyang population being the most prominent,reaching 78.93 cm,and Zhenghe,Songyang and Pingyang populations having larger ground diameter at seedling stage,9.43 mm and 9.08 mm,respectively.? In the comparative study of leaf traits,it was found that the leaf shape,thickness and internal components of leaves varied to different degrees,and there were significant or extremely significant differences in leaf length,leaf width and specific leaf surface between populations.This indicated that the leaf length and width of Phoebe bournei were greatly affected by environmental factors,and the fresh and dry weight of leaves among different populations were significantly different.(P<0.05),we can see the significant characteristics of leaf phenotypic differences,and there are abundant genetic variations in leaf area,leaf width and leaf length among different populations of Phoebe bournei.?The results of rhizome measurements of seedlings from six different populations of Phoebe bournei showed that Wuyuan population was the most representative of root traits,followed by Songyang population.There were significant differences in root fresh weight among different populations.The average root fresh weight of Wuyuan population was the highest,which was 20.63g.?The comparative analysis of seedling biomass among different populations of Phoebe bournei showed that the overall biomass of Pingyang population and Wuyuan population showed significant good characteristics(P>0.05),and their comprehensive ratios were greater than 0.05.The aboveground biomass,underground biomass and total biomass of each part of the sample were calculated according to the dry weight of each sample.Among them,the biomass of Pingyang population and Wuyuan population were very representative.(4)The photosynthetic characteristics of Phoebe bournei in seedling stage among different populations showed that the diurnal variation of Photosynthetic Physiological Indices among different populations was affected by photosynthetic active radiation(PAR)and atmospheric temperature(Ta).The diurnal variation curve of photosynthetic active radiation(PAR)was single peak,and the diurnal variation of relative humidity(RH)and atmospheric CO2 concentration(C2)was"single valley"curve.The diurnal variation trend of net photosynthetic rate(Pn)was different among different populations of Phoebe bournei,and the diurnal variation trend of leaf transpiration rate(Tr)was different among six different populations of Phoebe bournei;the diurnal variation trend of intercellular CO2 concentration(Ci)was different.It is mainly affected by the interaction of stomatal conductance(Gs),cell respiration and photosynthesis,and the law of Phoebe bournei leaf among different populations is that Zhenghe population is a"bimodal curve",the highest peak appears after 8:00,the second peak appears at 14:00,and the diurnal variation of stomatal conductance(Gs)of different populations is mostly a"unimodal curve";The chlorophyll content ranged from 3.00 to 3.70 mg.g-1,and the chlorophyll a/b values were about 2.80 mg.g-1 except for Pingyang population,while the chlorophyll a/b of leaves of Pingyang population reached the chlorophyll range of solar plants.The growth trend of characteristic light response curve of leaves of different populations of Phoebe bournei was basically the same.When PAR was 0-50 micromol.m-2.s-1,the Pn values of six different populations of Phoebe bournei were very good with PAR.Linear relationship showed a straight upward trend;when PAR was 100-400 micromol.m-2.s-1,Pn still increased with PAR enhancement,but the rate of increase tended to be slow.Pn was negatively correlated with Gs,Ci,Tr and RH in the analysis of photosynthetic characteristics of leaves of Phoebe bournei,among which Pn was positively correlated with Ta,while Pn was negatively correlated with PAR.In conclusion,the comprehensive characteristics of Phoebe bournei in different regions were compared in terms of 1000-grain weight,100-grain drainage volume and particle size,phenotypic growth characteristics,biomass and photosynthetic characteristics.The results showed that Pingyang population had good representativeness and plasticity in the selection of population in different regions. |
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