| As the representative species of fast-growing and high-yield timber forest in China,poplar were widely cultivated in recent years.Cuttage seedling raising is the main method of poplar seedling breeding,however,the excessive water loss of cuttings in vitro would inevitably lead to difficulty in rooting of cuttings.the water moisture content of cuttings could be improved by using negative pressure water filling principle,which could restore the water conducting of cuttings.as a consequence,the normal water transfer after the cutting could be ensured,the survival rate of cuttage seedling could be greatly improve,which promote the growth of cuttings.In this paper,different dehydration degree of Populus× euramericanna‘Neva’ annual cuttings were filled water by the use of negative pressure water filling device.The performance of conduction water,embolism recovery,rooting and growth were studied systematically,So as to clarify the application effect of negative pressure water filling technology in cuttage in woody plants.The results are as follows:Airing loss at different time gradient,the cuttings water potential and the water conductivity compared to the respective control were reduced by 519.05%-46.65%,1138.10%-52.57%,1376.19%-62.27%,2147.62%-71.64%,3328.57%-74.58%,4528.57%-87.72%.5247.62%-90.95%,6471.43%-93.80%,9109.52%-98.51%,the difference was remarkable(P< 0.05).(2)The survival rate of cutting seedlings was increased by 13.12%,18.95%,and 82.45%respectively,and the effect was significantly higher than that of the control group(P < 0.05).(3)After cutting 100 d,the plant height and the ground diameter were increased by 6.30%and 12.15%,14.91%,and 35.63%,respectively,and 22.70% respectively,and the difference between the two groups was remarkable(P < 0.05).At the end of growing season,by using the negative pressure water filling,the plant height and the ground diameter increased by 2.85 and 6.76%,12.29% and 51.06%,19.38% and 80.64% respectively,and the difference was significant(P < 0.05).(4)After negative pressure water treatment,the leaf area of cutting seedlings increased by 58.74%,122.80% and 32.32% respectively compared with their respective control,and the effect reached a significant level(P < 0.05).(5)After the treatment of negative pressure water compared to respective control in seedling root length,surface area,average diameter,volume and short root number index were increased by 30.70%-21.12%-14.87%,24.68%-49.82%-18.33%,4.44%-9.01%-13.42%,24.22%-18.23%-21.91%,25.78%-54.19%-5.19%,and the difference was significant(P <0.05).(6)After negative pressure water treatment,the biomass of cutting seedlings increased by86.85%,132.77% and 102.05% respectively compared with their respective control,the effect was respectively significant(P < 0.05).In summary,the loss of water can decreased the cuttings water potential,the water content and hydraulic conductivity significantly,which will lead to the formation of xylem embolism;but the negative pressure water filling technology can restore water transportation system of cuttings,significantly improve the survival rate of poplar seedlings,the growth,the biomass and the root morphology index,which promote the growth of the seedling,provide protection for the young trees of the fast-growing area. |
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