Effects of Guyot Tree Shape on Shoot Leaf Growth and Physiological Characteristics of Apple
In order to explore the effects of Guyot tree shaping on vegetative growth of apple trees,the 3-year-old'Venus Gold/M9'apple trees were used as test materials in this experiment.The leaf growth and de-velopment,chloroplast pigment content and photosynthetic characteristics of spring shoots in different parts of canopy,and the content change of leaf hormonesat stop-growing stage of spring and autumn shoots were deter-mined and analyzed.The results showed that the leaf area,leaf thickness,leaf weight,chloroplast pigment content and photosynthetic capacity in proximal leaves of the tree canopy were superior to those in distal leaves at the spring shoot growth stage;although there were differences in these indicators between the proximal and distal leaves at the early growth stage of spring shoots especially between the upper and lower parts,with the extension of growth stage,the distal leaves grew rapidly at later stage,so the differences in these indicators of the proximal and distal leaves decreased gradually until disappeared in the end.At the same time,at the stop-growing stage of spring shoots in late June,the contents of growth-promoting hormones such as gibberellin(GA3),indoleacetic acid(IAA)and zeatin riboside(ZR)in proximal upper leaves were higher than those in distal upper leaves,which was conducive to vegetative growth;at the stop-growing stage of autumn shoots in-late September,the content of abscisic acid(ABA)in the upper,middle and lower leaves of the proximal end were higher than that of the distal end,and the growth of the proximal autumn shoots was inhibited,which was conducive to the formation of flower buds.In conclusion,the Guyot tree shaping of'Venus Gold/M9'signifi-cantly promoted the leaf growth of proximal shoots at the early growth stage of new shoots,but the leaf growth and development of distal new shoots was slower;however,with the extension of growth period,there was no significant differences in the growth and physiological indicators of proximal and distal leaves at the later stage of new shoot growth.
AppleGuyot tree shapeLeaf growth of new shootsPhotosynthetic characteristicsGrowth hormone
万方数据
维普
