The combined effects of salinity with low root zone temperature （RZT） on plant growth and photosynthesis were studied in tomato （Solanum lycopersicum） plants. The plants were exposed to two different root zone tem...The combined effects of salinity with low root zone temperature （RZT） on plant growth and photosynthesis were studied in tomato （Solanum lycopersicum） plants. The plants were exposed to two different root zone temperatures （28/20℃, 12/8℃, day/night temperature） in combination with two NaC1 levels （0 and 100 mmol L-l）. After 2 wk of treatment, K＋ and Na~ concentration, leaf photosynthetic gas exchange, chlorophyll fluorescence and leaf antioxidant enzyme activities were measured. Salinity significantly decreased plant biomass, net photosynthesis rate, actual quantum yield of photosynthesis and concentration of K＋, but remarkably increased the concentration of Na＋. These effects were more pronounced when the salinity treatments were combined with the treatment of low RZT conditions. Either salinity or low RZT individually did not affect maximal efficiency of PSII photochemistry （Fv/Fm）, while a combination of these two stresses decreased Fv/Fm considerably, indicating that the photo-damage occurred under such conditions. Non-photochemical quenching was increased by salt stress in accompany with the enhancement of the de-epoxidation state of the xanthophyll cycle, in contrast, this was not the case with low RZT applied individually. Salinity stress individually increased the activities of SOD, APX, GPOD and GR, and decreased the activities of DHAR. Due to the interactive effects of salinity with low RZT, these five enzyme activities increased sharply in the combined stressed plants. These results indicate that low RZT exacerbates the ion imbalance, PSII damage and photosynthesis inhibition in tomato plants under salinity. In response to the oxidative stress under salinity in combination with low RZT, the activities of antioxidant enzymes SOD, APX, GPOD, DHAR and GR were clearly enhanced in tomato plants.展开更多
用实验生态学的方法研究了不同水温（15、20、25、30℃）、盐度（16、21、26、31、36）和饵料密度（0.5×10^4、1.5×10^4、2.5×10^4、3.5×10^4、5×10^4个/mL）对橄榄蚶（Estellarca olivacea）滤水率的影响。...用实验生态学的方法研究了不同水温（15、20、25、30℃）、盐度（16、21、26、31、36）和饵料密度（0.5×10^4、1.5×10^4、2.5×10^4、3.5×10^4、5×10^4个/mL）对橄榄蚶（Estellarca olivacea）滤水率的影响。实验结果表明,以金藻作为饵料,水温、盐度、饵料密度对橄榄蚶的滤水率有显著影响（P〈0.05）。水温15-30℃、盐度16-36、饵料密度为0.5-5×10^4个/mL时,橄榄蚶的滤水率都呈峰值变化。水温25℃、盐度26、饵料密度3.5×10^4个/mL时,其滤水率分别达到最大值。在所研究的范围内,水温、盐度、饵料密度与滤水率之间分别满足函数关系：FRT=–0.3396T2＋1.8937T＋0.2728（R^2=0.9857,P〈0.05）;FRS=–0.3424S2＋1.9626S＋0.7112（R^2=0.9683,P〈0.05）;FRC=1.7395 C 0.4607,（R^2=0.9062,P〈0.05）。展开更多
基金supported by the National Natural Science Foundation of China(31101585)the Cucurbit Vegetable Innovation Strategic Alliance Fund of Zhejiang Province,China(20101107)+1 种基金the Vegetable Innovation Group Fund of Zhejiang Province,China(2009R50026)the Zhejiang A&F University Science Development Fund,China(2009FR059)
文摘The combined effects of salinity with low root zone temperature （RZT） on plant growth and photosynthesis were studied in tomato （Solanum lycopersicum） plants. The plants were exposed to two different root zone temperatures （28/20℃, 12/8℃, day/night temperature） in combination with two NaC1 levels （0 and 100 mmol L-l）. After 2 wk of treatment, K＋ and Na~ concentration, leaf photosynthetic gas exchange, chlorophyll fluorescence and leaf antioxidant enzyme activities were measured. Salinity significantly decreased plant biomass, net photosynthesis rate, actual quantum yield of photosynthesis and concentration of K＋, but remarkably increased the concentration of Na＋. These effects were more pronounced when the salinity treatments were combined with the treatment of low RZT conditions. Either salinity or low RZT individually did not affect maximal efficiency of PSII photochemistry （Fv/Fm）, while a combination of these two stresses decreased Fv/Fm considerably, indicating that the photo-damage occurred under such conditions. Non-photochemical quenching was increased by salt stress in accompany with the enhancement of the de-epoxidation state of the xanthophyll cycle, in contrast, this was not the case with low RZT applied individually. Salinity stress individually increased the activities of SOD, APX, GPOD and GR, and decreased the activities of DHAR. Due to the interactive effects of salinity with low RZT, these five enzyme activities increased sharply in the combined stressed plants. These results indicate that low RZT exacerbates the ion imbalance, PSII damage and photosynthesis inhibition in tomato plants under salinity. In response to the oxidative stress under salinity in combination with low RZT, the activities of antioxidant enzymes SOD, APX, GPOD, DHAR and GR were clearly enhanced in tomato plants.
文摘用实验生态学的方法研究了不同水温（15、20、25、30℃）、盐度（16、21、26、31、36）和饵料密度（0.5×10^4、1.5×10^4、2.5×10^4、3.5×10^4、5×10^4个/mL）对橄榄蚶（Estellarca olivacea）滤水率的影响。实验结果表明,以金藻作为饵料,水温、盐度、饵料密度对橄榄蚶的滤水率有显著影响（P〈0.05）。水温15-30℃、盐度16-36、饵料密度为0.5-5×10^4个/mL时,橄榄蚶的滤水率都呈峰值变化。水温25℃、盐度26、饵料密度3.5×10^4个/mL时,其滤水率分别达到最大值。在所研究的范围内,水温、盐度、饵料密度与滤水率之间分别满足函数关系：FRT=–0.3396T2＋1.8937T＋0.2728（R^2=0.9857,P〈0.05）;FRS=–0.3424S2＋1.9626S＋0.7112（R^2=0.9683,P〈0.05）;FRC=1.7395 C 0.4607,（R^2=0.9062,P〈0.05）。
