Effects Of Rootstock Transplantation On Growth And Flowering Of Apple Seedlings

The overall quality of apple seedlings in China is still far behind that of foreign countries,and the quality of large seedlings is relatively low.Therefore,it is urgent to cultivate high-quality apple seedlings.In this research,the following materials,including a biennial dwarf rootstock anvil(M9-T337),a dwarfed intermediate anvil(M9-T337/ Malus Robusta)and a Qiaohua anvil(Malus Robusta).The grafted variety is the bud full of Yanfu 3,Gala,Lifu 1 and Micui branches.They were transplanted on March 23,2018,and grafted time on April 10,2018.This study used a three-factor split test design.The main area(A)is treated as transplanting(A1)and not transplanting(A2).The sub-area(T)is treated as three different rootstock types: M9-T337(T1),M9-T337/Malus Robusta(T2),and Malus Robusta(T3),and the secondary sub-area(V)is treated as Yanfu 3(YF),Gala(GL),Lifu 1(LF),and Micui(MC),(the scion varieties are treated as treatment).By comparing the differences in the growth and flowering of apple seedlings between transplanting and not transplanting,it is easy to understand her growth situation among different apple seedlings,which can provide some theoretical basis for cultivating high quality early flowering apple seedlings.The main findings of this test are as follows:1.The transplanting of rootstock inhibited the growth of seedling height,stem diameter and rootstock.The total number of branches,the number of long branches,total biomass,aboveground biomass,main root biomass,and leaf SPAD value decreased significantly;The growth of lateral roots,medium and short branches,total length of roots,total surface area of roots,total number of root tips,the root length of seedlings(diameter of roots <4.5 mm)and lateral root biomass of seedlings increased significantly;under the conditions of transplanting and rootstock type interaction,plant height and stem diameter are extremely significant.Under the combined action of transplanting and scion,the SPAD value,total root length,total root surface area and total root volume and two diameter root lengths(0-0.5 mm?0.5 mm-2 mm)are extremely significant.In general,the growth of roots was promoted and the growth of aboveground parts was inhibited to some extent after transplanting,but the overall growth of seedlings was still good,and the above-ground and under-ground parts were coordinated to grow,effectively avoiding the phenomenon of "growth redundancy” of seedlings.2.Under the condition of rootstock transplanting,M9-T337 were flowering while,M9-T337/M.r.R,M.r.R and unplanted conditions were not flowering,indicating that rootstock transplanting is helpful for seedling flower bud differentiation,M9-T337/M.r.R,M9-T337/M.r.R.,M.r.R may not be flowering after transplanting may be due to weaker flowering ability than M9-T337.3.The three rootstock types showed different growth under the condition of rootstock transplanting.The effect of transplanting treatment on the overall growth and flowering of seedlings was M9-T337>M9-T337/M.r.R.>M.r.R.4.There are also large differences among the four varieties under the condition of transplanting rootstocks.In terms of the overall growth of seedlings,the growth and flowering situation of Gala and Lifu 1 is better than that of Yanfu 3 and Micui.The transplanting of rootstocks accelerates the transformation of seedlings from vegetative growth to reproductive growth,balances the growth of seedlings,is conducive to early flowering,and can be used as a way to cultivate high-quality early-formed apple seedlings in the future.