Study On Adaptability And Foliar Fertilization Effect Of Introduced Hybrid Poplars In Ili Area

Ili experimental center of tree breeding for improved varieties has made great contribution to the cultivation and popularization of fine tree species suitable for local natural environment.In recent years,the experimental center introduced hybrid poplars from Liaoning,trying to select the fine tree species for suitable site conditions,domestication and promotion,which solve the problem of single degeneration,poor resistance,optimized in the development of the afforestation system in Xinjiang.At the same time,it can enrich the poplar germplasm pool.The introduction of hybrid poplars must be cultivated scientifically and reasonably,and its adaptability in the region was determined by the micro-macro physiological and ecological responses of hybrid poplar.From July to August in 2017,the hybrid poplars were selected as the research object,evaluated comprehensively,which determined by the photosynthetic index,growth index,photosynthetic growth performance as well as absorption and utilization efficiency under foliar fertilization.The research results showed that:（1）There are significant differences in photosynthetic physiological parameters of hybrid poplars.LD-3,LX-2,DS-07-122,84-306,93-8-18,D5-26,Zhongsui 12#have strong photosynthetic capacity.93-8-17,D5-20,93-8-18,CD-2,TL-13,DX-08-1 have low water use efficiency and transpiration water consumption.G_s,PAR,RH,WUE,T_r and T_l promoted the P_n of hybrid poplars,C_i,C_a,WUE,RH and T_l inhibit the its P_n.（2）Usinng the right-angle hyperbolic correction model to fit the light response parameters.The photosynthetic potential of LX-2,84-306,I-262 and D5-20 were large,meanwhile,CL-6,LX-6,LX-1 and 108 were slightly weaker in the photosynthetic potential.CL-6,93-8-18,108,93-8-1 and LX-6 have strong adaptability under low light;most of hybrid poplars have high conversion efficiency;CL-6,93-8-18,108,LX-6 are more beneficial to the conversion of organic matter accumulation,nevertheless,I-262,LX-2,D5-20 with vigorous physical activity,it need to consume more organic matter.（3）The growth characteristics of hybrid poplars were significantly different,the tree hight of 84-306,LX-1,LD-3,108,LD-2,93-8-17 had obvious advantages,the ground diameter of LD-3,84-306,LD-2,LX-6,DX-08-8 had obvious advantages.The growth fast=growig period of each clone was mostly oncentrated from late July to early August,which the increase in growth volume during different growth periods was significantly different.LX-1,84-2,d5-26,LX-2 and I-262 had higher chlorophyll content.The leaf area of CD-2,DM-9-16,LX-2,Zhongsui 12#,I-262 were larger;the leaf loss rate of TL-13 was the largest,it was slightly affected by pests and diseases,and the other clones belonged to healthy.（4）Different concentrations of foliar fertilizers had different effects on photosynthetic growth characteristics of 93-8-18,108 and DM-9-16,and the same concentration of foliar fertilizer had different effects on different clones,spraying suitable concentrations of foliar fertilizer can improve the photosynthetic capacity,growth and chlorophyll content of hybrid poplar.At the concentrations of 4.5 g·L^-1,3 g·L^-1,4.5 g·L^-1,the 93-8-18,108 and DM-9-16 of comprehensive photosynthetic parameters,growth and chlorophyll content,had the highest comprehensive score.（5）At different time,the influence of foliar fertilization on tree height was more than the impact on ground diameter.The photosynthetic parameters,growth,chlorophyll content of 21:00 fertilization group were the highest,11:00 fertilization group had the largest biomass,the total potassium content was highest in 20:00fertilization group,and the total potassium accumulation and total potassium storage in 10:00 group was highest,the total potassium utilization efficiency in 19:00 group was highest.The total potassium distribution rate in vegetative organs was expressed as leaf>stem>root.（6）According to the clustering result of the comprehensive evaluation of hybrid poplar adapation,the three hybrids with excellent adaptability of LX-2,LD-3 and DX-08-1 were selected and suited promotion in Ili region.The results of Brekin’s multi-trait comprehensive evaluation showed that foliar fertilization was beneficial to the improvement of photosynthetic growth in 21:00,and foliar fertilization was conducive to promoting the absorption and utilization of potash fertilizer by plants in10:00.In addition,the comprehensive score of the fertilization group was the highest in 21:00.Foliar fertilization at 21:00 facilitates the growth of hybrid poplar and the use of potash fertilizers.In summary,LX-2,LD-3 and DX-08-1 are adaptable and suitable for popularization;the foliage fertilization at 21:00 was beneficial to the growth of hybrid poplar and fertilizer utilization.