The physiological and anatomical changes in leaves of Poinsettia (Euphorbia pulcherrima) tube_plantlets occurred in the process of transplantation and acclimation were investigated in this paper. Before transplantatio...The physiological and anatomical changes in leaves of Poinsettia (Euphorbia pulcherrima) tube_plantlets occurred in the process of transplantation and acclimation were investigated in this paper. Before transplantation and acclimation, leaves of the tube_plantlets were apparently thin and the vascular system was not well developed, and the net photosynthetic rate of the plantlet was low, but the stomatal conductance and transpiration rate of the leaves were relatively high. At the early stage of transplantation, the tube_plantlet was vulnerable to relative low humidity and intense light that could resulted in wilting of leaves due to excess water loss. During the acclimatization, the net photosynthetic rate of the plantlets increased progressively and the stomatal conductance and transpiration rate decreased gradually, accompanied by an increase in the thickness of the leaves and the size of leaf epidermal cells, together with the fully development of vascular system, palisade and spongy tissues in leaves. The results indicated that the acclimatization could greatly improve the photoautotrophic ability of the tube_plantlets, bring anatomical changes to the plantlets in order to avoid excessive leaf dehydration for the gradual adaptation of the plantlets to natural environment.展开更多
[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sod...[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sodium chloride with the concentration of 0 mmol/L and 100 mmol/L.After 20 days,Na+ content and Na+/K+ ratio in the roots,shoots and leave were determined by the flame photometer,while dry weight and fresh weight of roots,shoots and leave in different varieties were also studied.[Result]The growth of two sweet potato varieties was inhibited under salt stress,so the plant became shorter,leaf and root became fewer,dry weight of roots and leave decreased,but seedlings of Xu 25-2 were inhibited slightly.Furthermore,Na+ content and Na+/K+ ratio in roots,shoots and leaves of two sweet potato varieties increased.Na+ content of salt-tolerant Xu 25-2 was low in roots,shoots and leaves,while Na+ content of salt-sensitive Triumph 100 was high in shoots and leave of seedlings,but the change range of Xu 25-2 was less than that of Triumph 100.[Conclusion]The lower Na+ content and Na+/K+ ratio in leaves under salt stress were the most important characteristics for salt-tolerance of sweet potato varieties.展开更多
文摘The physiological and anatomical changes in leaves of Poinsettia (Euphorbia pulcherrima) tube_plantlets occurred in the process of transplantation and acclimation were investigated in this paper. Before transplantation and acclimation, leaves of the tube_plantlets were apparently thin and the vascular system was not well developed, and the net photosynthetic rate of the plantlet was low, but the stomatal conductance and transpiration rate of the leaves were relatively high. At the early stage of transplantation, the tube_plantlet was vulnerable to relative low humidity and intense light that could resulted in wilting of leaves due to excess water loss. During the acclimatization, the net photosynthetic rate of the plantlets increased progressively and the stomatal conductance and transpiration rate decreased gradually, accompanied by an increase in the thickness of the leaves and the size of leaf epidermal cells, together with the fully development of vascular system, palisade and spongy tissues in leaves. The results indicated that the acclimatization could greatly improve the photoautotrophic ability of the tube_plantlets, bring anatomical changes to the plantlets in order to avoid excessive leaf dehydration for the gradual adaptation of the plantlets to natural environment.
基金Supported by the National Natural Science Foundation(30670177)Scientific Research Foundation for the Outstanding Young Scientist of Shangdong Province(006BS06002)National Ministry of Education Doctoral Fund(20050445003)~~
文摘[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sodium chloride with the concentration of 0 mmol/L and 100 mmol/L.After 20 days,Na+ content and Na+/K+ ratio in the roots,shoots and leave were determined by the flame photometer,while dry weight and fresh weight of roots,shoots and leave in different varieties were also studied.[Result]The growth of two sweet potato varieties was inhibited under salt stress,so the plant became shorter,leaf and root became fewer,dry weight of roots and leave decreased,but seedlings of Xu 25-2 were inhibited slightly.Furthermore,Na+ content and Na+/K+ ratio in roots,shoots and leaves of two sweet potato varieties increased.Na+ content of salt-tolerant Xu 25-2 was low in roots,shoots and leaves,while Na+ content of salt-sensitive Triumph 100 was high in shoots and leave of seedlings,but the change range of Xu 25-2 was less than that of Triumph 100.[Conclusion]The lower Na+ content and Na+/K+ ratio in leaves under salt stress were the most important characteristics for salt-tolerance of sweet potato varieties.
