Physiological Research On The Response Of Kiwifruit Tolerant-Rootstock To Hypoxia Stress

This paper based on the cutting seedlings of Actinidia valvata?submergence tolerant rootstock?and Actinidia chinensis seedlings?common stock?as rootstock,studied the effects of two rootstocks on the annual seedlings of'Donghong','Xiangjihong'and'Hongyang'kiwifruit plant on the growth of branches and leaves.The effects of the chlorophyll fluorescence parameters,MDA content and antioxidant enzyme activities?SOD,POD?on'Donghong'and'Xiangjihong'kiwifruit during flooding.Under the waterlogging stress,the effects of two rootstocks on'Hongyang'kiwifruit leaf cell membrane permeability,fence palisade and sponge tissue structure,and the effects of the root porosity,aerenchyma and endogenous hormones of two kinds of rootstocks.And Main results of this work are as follows:1.The leaf area of the'Donghong','Xiangjihong'kiwifruit on the calyx kiwi is larger than that of the delicious kiwi rootstock.On submergence tolerant rootstock'Donghong','Xiangjihong'and'Hongyang'internode length is longer than the common rootstock,and on submergence tolerant rootstock'Hongyang'Kiwifruit branch diameter increases.2.During the waterlogging period,the chlorophyll fluorescence parameters of the red root and the common rootstocks varied with the parameters of'Donghong'and'Xiangjihong'kiwi.The levels of ETR in Kiwifruit were increased,and the levels of Fv/Fm were decreased,while the submergence tolerant rootstock of kiwifruit was no difference change.The Y?II?,qN,of common rootstock kiwifruit and flooding'Donghong'decreased while the qP showed the opposite trend.Resistance to flooding'Xiangjihong'kiwi Y?II?,qN,qP and other three fluorescence parameters showed a steady state..The three fluorescence parameters of the kiwi fruit and the sub-tree status.The changes of these fluorescence parameters indicate that the flooded root can keep the original chlorophyll fluorescence of'Xiangjihong'kiwi fruit,and has better photosynthetic characteristics than'Donghong'kiwi fruit.3.The content of MDA in the roots of Kiwifruit was increased and the activity of SOD decreased first and then decreased.With the prolongation of waterlogging time,the POD activity of kiwifruit in common rootstock increased first and then decreased,and the POD activity of resistant root was lower.During the process of waterlogging,the changes of POD and SOD activity were different,but the content of MDA in the rootstock was faster than that of the common rootstock4.The permeability of the membrane of'Hongyang'kiwifruit on submergence tolerant rootstock kept at a relatively stable level during the whole flooding process,while the cell membrane permeability of kiwifruit leaves of the common stock increased with the prolongation of flooding time.In leaf anatomical structure,the leaf palisade organization on the common rootstock was disordered,the spongy tissue disorder did not swell,while the leaf palisade tissue on the submerged rootstock was loose and neat.The leaf lower epidermal cells and spongy tissue were linked to form aeration tissue.5.Under the waterlogging stress,the root porosity of kiwifruit of different rootstocks increased first and then decreased with the increase of flooding time.The root porosity of the submergence-resistant rootstock was always higher than that of the common rootstock,and there was significant difference between the two.The changes of root morphology,submergence-tolerant rootstock in the second day has grown a lot of adventitious roots,the increasing number of vitality,common rootstock roots in the late most fester;in the anatomical structure of root,rootstock of submergence tolerance formed aerenchyma and cavity is developed,and the ventilation form common rootstock roots the scattered and divided connection space between cells.In waterlogging period,the content of GA₃ in the roots of Kiwifruit increased first and then decreased,and the content of ABA decreased first and then decreased,and the content of ACC increased first and then decreased in the common rootstocks.The GA₃/ABA decreased in the same way.The rootstock showed an upward trend,and the resistance of the rootstock was increased and then increased,and ACC/ABA continued to decrease in the common stock.