| In this research,different ages of fraxinus mancdshurica.were chosen as experimental materials.First of all,rules of pollen dispersal in the fraxinus mandschurica seed orchard were studied and concluded.Secondly,a comprehensive analysis that different influences on flowering,growth and photosynthesis by different treatments was observed and measured,in which the treatments were fertilization and hormones application to flowering,immature trees and grafted seedlings of fraxinus mandschurica in the seed orchards.Furthermore,genes related to flowering(FLC,FT,FRI,et al.)and hormones were measured to analysis the different responding to different treatments above.Details are as follows:1.Study on the distributing rule of pollen of fraxinus mandshurica in seed orchardIn this study,we observed and measured the distribution of fraxinus mandshurica pollen dispersal in temporal and spatial,horizontal and vertical aspects,and summarized the distributing rule of pollen,in seed orchard,QingShan forestry station of WeiHe forestry bureau.Male flowers started dispersing pollen in May 10 and continued dispersal to May 15.It was close relationships between changes of temporal and spatial,distribution of horizontal and vertical and environmental factors.The concentration of pollen in dispersal peak period was 6m>4m>2m,and it was 11.5pcs mm-2h-l at 6m.The maximum pollen concentration was 1.58pcs mm-2h-1 occurred from 9 a.m.to 3 p.m..Environmental factors(wind speed,temperature,relative humidity,wind direction)played a major role among the factors influencing pollen dispersal.and temperature was the most important factor in the factors that affected the amount of pollen.The highest daytime temperature reached 29.6? and the average wind speed was 2.1m/s.Temperature was the dominant factor among the factors influencing the amount of pollen.2.Study on influences of flowering,fruiting and growth under different treatments in fraxinus mandshuricaIn this research,we fertilized and applied hormones to flowering,immature trees and grafted seedlings of fraxinus mandschurica in the seed orchards.We calculated the seeding quantity and seeding rate of flowering trees in 2013.During 2013 and 2014,we measured the tree height,diameter at breast height(basal diameter)and current increment which from immature trees in no-flowering forest and grafted seedlings in the greenhouses,respectively.The amount of flower bud was 900 per plant,which was higher 155%than it in the control group.The seeding rate was 75.34%per female inflorescence,which was higher 18.16%than it in the control group.During 2013 and 2014,the single of growth was up to 110cm and 130cm in no-flowering forest,which was higher 70.54%and 66.03%than the control,respectively.The highest growth of grafted seedlings in the greenhouses was up to 155cm,which was 148.8%higher than the control in 2014.fraxinus mandschurica was related closely to fertilization and application of hormones,that is to say,the growth of treated trees was significantly better than untreated trees.After analyzing the growth of immature trees in 2013 and 2014,we concluded the treatments that significantly influenced the growth of fraxinus mandshurica..The NO.4(the mixture of 15mg/L GA3,15mg/L NAA,30mg/L IAA)was the best treatment in hormones application,which average growth was 77±9.75cm and it was higher 7.89%than the control;the N0.9(the mixture of 0.3kg ammonium nitrate,0.3kg diammonium phosphate,0.1kg potassium chloride compost)was the best treatment among the fertilization treatment,which average growth was 98.2 ±8.62cm and it was higher 37.54%than the control.At the same time,the average growth of 2m x 2.5m density treatment was 84.33±10.27cm,which was higher 7.66%than the control;the average growth of plowing to increasing soil temperature was 83.11±8.07cm,which was higher 16.35%than the control;the average growth of topping treatment was 72.08cm,which was higher 0.09%than the control.3.Expression level of genes about flowering under different treatmentsIn this study,we analyzed the gene expression of flowering under fertilization and hormones application in grafted seedlings(2 years old).After fertilization and hormones application,FLC(FLOWERING LOCUS C)and FRI(FRIGIDA)gene expression was significantly decreased and lower than in the control group,except that the expression of FLC was higher in male seedlings for N0.4 hormones treatment;while the expression of FLC in female seedlings was lower than the control.FLC and FRI are key genes controlling flowering synergy,both of them play an inhibitory effect on flowering,thus,fertilization and hormones treatment could weaken the expression of FLC and FRI,and promote flowering in fraxinus mandshurica.The expression of FT(FLOWERING LOCUS T)and FLD(FLOWERING LOCUS D)were inconsistent,FT expressed higher than control in NO.2,3,4,and 6 in male seedlings under fertilization treatment and it was 3.7 fold in N0.3 as in the control.FLD expressed higher than control in NO.3,4,5,7,and 9 in female seedlings under hormones treatment and it was 2.6 fold in N0.3 as in the control.4.The content of hormone after various treatmentsIn this research,we analyzed the content of hormones(GA3,6-BA,NAA,IAA and ABA)in seedlings(2 years old)under different treatments.The highest content of GA3 was 4.01ng/gFW in density of 2m x 2.5m,which was higher 63.67%than the control;the highest content of 6-BA was 0.44ng/gFW in density of 6m X 10m,which was higher 22.22%than in the control;the highest content of NAA was 4.09ng/gFW in NO.7 treatment of hormones application,which was higher 154%than in the control;the highest content of IAA was 0.43pmol/gFW in the density of 6m X 10m,which was higher 59.25%than in the control;and the highest content of ABA was2.78ug/gFW in the control The content of GA3 was positive correlated with current increment,while the content of ABA in some seedlings was negative correlated with current increment,the content of the other hormones had little relationship with current increment?Therefore,GA3 and ABA paly antagonistic roles in faxinus mandshurica.growth.5.Measurement photosynthesis of fraxinus mandschurica under different treatmentsIn this study,we analyzed the photosynthesis in grafted seedlings(2 years old)under fertilization and hormone treatments.Overall it was stronger in fertilization than in the hormone treatment,the average transpiration rate(1.08794mmolH2Om-2s-1)was higher in fertilization than in the hormone treatment(0.965966 mmolH2Om-2s-1),and the average net photosynthetic rate in fertilization(5.305887 umolCO2m-2s-1)was also higher than in hormone treatment(4.098145 umolCO2m-2s-1).It was positive correlation between the photosynthetic rate and current increment in the overall results. |
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