The Growth Dynamic Of Dwarfing Self-rooted Rootstock Apple Nursery And Root Architecture Research

1-year-old and 2-year-old dwarfing self-rooted rootstock apple nursery(Fuji/M9) were as test material. Using Logistic equation simulation the growth dynamic of 1-year-old dwarfing self-rooted rootstock apple nursery and analysised root spatial distribution of apple nursery. At the same time, from the view of root, study the effects of different branch management on root architecture and root distribution of apple nursery. Also research the relationship between root endogenous hormones and root architecture. To find out the rules of the growth dynamic and root architecture of dwarfing self-rooted rootstock apple nursery. And provide theory and method for root architecture theory of apple tree.The results shows,(1) 1-year-old apple nursery shoot growth approximation “curves of S” type. And apple nursery shoot growth can be divided into three periods: the increasing growth period, fast growth period, slow growth period.(2) Root system reached a growth peak in June and September; A large amount of root death in July and August. In the horizontal direction absorbing roots and conducting roots were mainly distributed in 0~30 cm. In vertical direction absorbing roots were concentrated distributed in the 0~40 cm, conducting roots were distributed in the 0~30 cm. Root length density in the horizontal direction and vertical direction were showed exponential decay law. Also, the root distribution of 1-year-old dwarfing self-rooted rootstock apple nursery was in line with the two-dimensional exponential distribution through established a two-dimensional root density equation. Root architecture of self-rooted rootstock apple nursery have the following characteristics, no main root, lateral roots are concentrated in the stock in the lower part, the horizontal root widely distributed, etc.(3) Plant height and average leaf area of branch pruning trees were significantly higher than branch promoting trees and control, Pn, Gs, Tr, Ci of branch pruning trees leaves were higher than branch promoting trees and control. So branch pruning trees showed higher photosynthetic capacity.(4) Total root length, total root surface area, the number of root tips, absorbing roots and conducting roots of branch promoting trees were significantly higher than branch pruning trees and control. The the number of first lateral roots, second lateral roots and lateral lengths increased significantly under branch promoting treatment. But the number of first lateral roots, second lateral roots and lateral lengths were lower under branch pruning treatment. The root activity of branch promoting trees were significantly higher than branch pruning trees and control. In the vertical direction, the root distribution of each branching treatment as a inverted pyramid under 10 cm soil depth. The root of branch promoting trees and control were mainly distributed in the horizontal direction 0~50cm, in the vertical direction 10~50cm,and the root of branch pruning trees were mainly distributed in the horizontal direction 0~20cm, in the vertical direction 0~30cm. The distribution of absorbing roots and conducting roots was wide and deep under branch promoting treatment and control.(5) Root IAA content of branch promoting treatment was higher than other treatments. And ABA content of branch pruning treatment was higher than other treatments. The ratio of IAA/ABA, IAA/ZT,(IAA+GA)/(ZT+ABA) was highest under branch promoting treatment and. So it’s indicating root was more vigorous under branch promoting treatment.According to the results, 1-year-old apple nursery shoot growth approximation “curves of S” type. Root architecture of self-rooted rootstock apple nursery have the following characteristics, no main root, lateral roots are concentrated in the stock in the lower part, the horizontal root widely distributed, etc. With different branch promoting treatments, apple nursery branching numbers and root absorption capacity were good, root absorption of nutrients and water from soil was more easily under root architecture of branch promoting treatment.