Effect Of Different Rootstocks On Chilling Requirement And Endogenous Polyamines Metabolism During Dormant Period In 'Fujiminori' Grapes

This experiment was carried out during 2004-2006 in Yang Zhou University with grape variety Fujiminori (cuttings), grape rootstock SO4 (Selection oppenheim No.4, V.berlondieri×V. riparia) , grape rootstock DE( DogRidge, V. champini), Fujiminori grafted on rootstock SO4 (Fujiminori/SO4) and Fujiminori grafted on rootstock DE (Fujiminori/DE) as experimental materials. The changes of chilling requirements in different test materials were investigated, and the changes of endogenous polyamine kinds,forms and contents in the buds of different test materials during dormant period were analyzed. Also the effect of chemicals 20%CaCN2 and 2%H2CN2 which are usually used as breaking dormancy were studied on the kinds,forms and contents of endogenous polyamines in the buds of grape variety Fujiminori. The methods for determining free,conjugate and bound polyamine contents by HPLC were discussed in this article. The main results were as fellow:1. Comparing the applicability of three models measuring the chilling requirements with data of investigations in 2004 and 2005,it is found that the Utah model is much more suitable to describe the changes of dormant course of the grape buds in YangZhou and different rootstocks play an important role in fulfilling the chilling requirements of dormant buds in Fujiminori grape.2. Putrescine,cadaverine ,hexanediamine,spermidine and spermine five kinds of endogenous polyamines were detected in the buds of test materials, which exist as free, conjugate and bound forms in plant tissues. It can be seen that the changes and contents of free and conjugate polyamines are more special and higher than that of bound polyamines and free and conjugate spermine.Only free, conjugate and bound cadaverine and hexanediamine could not been detected in the grape buds until the chilling requirements of dormant buds were satisfied.3. Along with sufficing in the chilling requirement of dormant buds , the contents of the free and conjugate putrescine and spermidine gradually increased in the buds of Fujiminori grape. Since the content changes of the free and conjugate putrescine and spermidine were significantly influenced in the dormant buds of Fujiminori grape by different rootstocks, which was consistent with effect of rootstocks on the chilling requirement of dormant buds above, it seems that the content changes of the free and conjugate putrescine and spermidine could be used as an index of physiological metabolism for estimating dormancy depth of buds of Fujiminori grape.4. In prophase of dormancy, it was found that the contents of the free and conjugate putrescine and spermidine was relatively low in the buds of grape rootstock SO4 ,in which the chilling requirement is low, while on the contrary, the contents of the free and conjugate putrescine and spermidine was relatively high in the buds of grape rootstock DE in which the chilling requirement is high also. It is possible that the level of the free and conjugate putrescine and spermidine in the buds of grapes could be used as an index for forecasting the chilling requirement of the buds of grape plants in prophase of dormancy.5. The dormancy of grape buds could not only be broken by the treatments which was composed of 20%CaCN₂ and 2%H2CN₂, but also by which the contents of the free and conjugate putrescine and spermidine could be induced and increased in the dormant buds of Fujiminori grape. It can be presumed that the content changes of the free and conjugate putrescine and spermidine would play an very important role in dormancy regulation of grape plants.