Comparative Analysis of Growth,Photosynthetic Physiology and Root Tip Ion Flow Characteristics of Five Poplar Varieties
To provide reference for early selection of fast-growing and adaptable varieties,the difference in growth,photosynthetic physiology,and root tip ion flux were analyzed among in five poplar varieties.The annual seedlings of Populus×euramericana'Bofeng 3',P.×euramericana'Bofeng 1',P.×euramericana'Xixiong 1',P.×euramericana'Zhongxiong 7',and P.deltoides×P.suaveolens cl.'Zhongxiong 4'were selected as materials.Growth indexes including plant height and ground diameter were measured at 0 and 30 days under normal culture conditions,respectively.Leaf number,single leaf area,leaf length,leaf width,photosynthetic parameters including Pn,Ci,Gs,Tr,SPAD and K+,Ca2+,H+ ion flux of roots were measured at 10,20 and 30 days,respectively.Under 30 days normal management,There were significant differences in plant height growth among the five varieties,from high to low,it was'Zhongxiong 4','Xixiong 1','Bofeng 3','Zhongxiong 7'and'Bofeng 1'.Among them,the photosynthetic characteristics and transpiration rate of'Bofeng 1'were the largest,and those of'Zhongxiong 4'were the smallest.However,the single leaf area((57.49±2.37)cm2),total leaf area((1 721.10±28.59)cm2),net photosynthetic rate((17 863.10±910.21)μmol·m-2·s-1)and water utilization rate((3.15±0.06)μmol·mmol-1)of'Zhongxiong 4'were significantly decreased.were the largest.The efflux velocity of K+ was the slowest((62.68±0.45)pmo·l cm-·2 g-1),and the influx velocity of Ca2+ was the fastest((-74.24±1.29)pmol·cm-2·g-1).The net photosynthetic rate((8 539.70±164.64)μmol·m-2·s-1)and water utilization rate((2.64±0.07)μmol·mmol-1)of'Bofeng 1'were the lowest,and the outflow velocity of K+ was(130.81±1.71)pmol·cm-·2 g-1.The Ca2+ influx velocity((-34.43±0.84)pmol·cm-·2 g-1)was the slowest.In summary,among the five varieties,'Zhongxiong 4'might have potential strong environmental adaptability,with the highest total leaf area,Pn and WUE,the lowest Tr,the smallest K+ efflux,largest Ca2+ influx of and most active H+ of root tip,and best plant height growth performance,which might be suitable for planting a wider range.
poplar varietiesgrowth differencephotosynthesistranspirationapical ion flow rate