NaCl胁迫对醋栗番茄、樱桃番茄和番茄幼苗生长、叶片气体交换和离子平衡的影响

Effect of NaCl stress on growth,leaf gas exchange and ion balance of seedlings of Solanum pimpinellifolium,S.lycopersicum var.cerasiforme and S.lycopersicum

以醋栗番茄(Solanum pimpinellifolium Linn.)、樱桃番茄品种‘秦皇贵妃红’(S.lycopersicum var.cerasiforme‘Qinhuangguifeihong’)和番茄品种‘浙粉202’(S.lycopersicum‘Zhefen 202’)幼苗为材料,研究了0(对照)、100、200mmol·L-1Na Cl胁迫对其生长、叶片气体交换参数和离子平衡的影响。结果表明:在100和200 mmol·L-1Na Cl胁迫下,‘秦皇贵妃红’和‘浙粉202’幼苗单株总干质量的降幅较大,醋栗番茄的降幅较小。Na Cl胁迫明显增加醋栗番茄幼苗的根冠比,但不同胁迫条件下‘秦皇贵妃红’和‘浙粉202’幼苗的根冠比差异不显著。与对照相比,在100mmol·L-1Na Cl胁迫下,醋栗番茄幼苗叶片的净光合速率(Pn)、胞间CO2浓度(Ci)和蒸腾速率(Tr)的降幅明显低于‘秦皇贵妃红’和‘浙粉202’,而醋栗番茄幼苗叶片气孔导度(Gs)的降幅明显高于后二者;在200 mmol·L-1Na Cl胁迫下,三者叶片Pn、Gs、Ci和Tr值的降幅接近。在100和200 mmol·L-1Na Cl胁迫下,醋栗番茄、‘秦皇贵妃红’和‘浙粉202’幼苗叶片的水分利用效率和气孔限制值均较各自对照显著升高,其中‘秦皇贵妃红’的增幅最大。在100和200 mmol·L-1Na Cl胁迫下,醋栗番茄、‘秦皇贵妃红’和‘浙粉202’幼苗根、茎和叶中Na+含量均较各自对照显著升高,而K+含量和K+/Na+比总体上较各自对照显著降低。与对照相比,经不同浓度Na Cl处理后醋栗番茄幼苗根、茎和叶的Na+含量增幅以及K+含量降幅在供试3种植物中均最小,而其不同部位的K+/Na+比总体上较高。上述研究结果表明:醋栗番茄的耐盐性较强,‘秦皇贵妃红’次之,‘浙粉202’较弱。Na Cl胁迫显著抑制‘秦皇贵妃红’和‘浙粉202’幼苗根的生长,但显著促进醋栗番茄幼苗根的生长,使其维持较强的耐盐性,且Na Cl胁迫下醋栗番茄对Na+的吸收和运输减少,以维持体内的离子平衡及较强的光合作用。

Taking seedlings of Solanum pimpinellifolium Linn., S. lycopersicum var. cerasiforme ‘ Qinhuangguifeihong ’ and S. lycopersicum ‘ Zhefen 202 ’ as materials, effect of 0 （ the control） ,100 and 200 mmol·L^-1 NaCl stresses on their growth, leaf gas exchange parameters and ion balance was studied. The results show that under 100 and 200 mmol·L^-1 NaCl s tresses, decreasing range of total dry weight per plant of ‘ Qinhuangguifeihong ＇ and ‘ Zhefen 202 ＇ seedlings is bigger, and that of S. pimpinellifolium is smaller. NaCl stress can obviously enhance root/shoot ratio of S. pimpinellifolium seedling, but difference in root/shoot ratio of ‘ Qinhuangguifeihong’ and ‘ Zhefen 202 ＇ seedlings is not significant under different stresses. Compared with the control, under 100mmol·L^-1 NaCl stress, decreasing ranges of net photosynthetic rate （ Pn ） ,intercellular CO2 concentration （ Ci） and transpiration rate （Tr） of leaf of S. pimpinellifolium seedling are obviously lower than those of ‘ Qinhuangguifeihong ’ and ‘ Zhefen 202 ’,while that of stomatal conductance （ Gs） of leaf of S. pimpinellifolium seedling is obviously higher than that of the latter two. Under 200 mmol·L^-1 NaCl stress, decreasing ranges of P n, Gs,Ci and Tr values of leaves of S. pimpinellifolium, ‘ Qinhuangguifeihong ’ and ‘ Zhefen 202 ’ are close. Under 100 and 200 mmol·L^-1 NaCl stresses,water use efficiency and stomatal limitation value ofleaves of S. pimpinellifolium, ‘ Qinhuangguifeihong ’ and ‘ Zhefen 202 ’ seedlings are significantly higher than those of their respective control,in which,increasing range of ‘ Qinhuangguifeihong ’ is the biggest. Under 100 and 200 mmol·L^-1 NaCl stresses, Na^＋ content in root, stem and leaf of S. pimpinellifolium,‘ Qinhuangguifeihong ’ and ‘ Zhefen 202 ’ seedlings increases significantly than those of their respective control,while K^＋ content and K^＋/Na^＋ ratio totally decrease significantly than those of their respective control. Compared with the control,after treated by different concentrations of NaCl, increasing range of Na^＋ content and decreasing range of K^＋ content in root,stem and leaf of S. pimpinellifolium seedling are all the lowest in three plants tested, while,its K^＋/ Na^＋ ratio in different parts is higher generally. It is suggested that salt tolerance of S. pimpinellifolium is stronger, that of ‘ Qinhuangguifeihong ’ is the second, and that of ‘ Zhefen 202 ’ is weaker. NaCl stress can significantly inhibit root growth of‘ Qinhuangguifeihong ’ and ‘ Zhefen 202 ’ seedlings, while it can significantly promote that of S. pimpinellifolium to maintain stronger salt tolerance. Under NaCl stress, Na＋ uptake and transport of S. pimpinellifolium decrease for maintaining ion balance and stronger photosynthesis.