A greenhouse experlment was performed In order to Investigate the effects of dlfferent levels of water stress on leaf water potentlal （ψw）, stomatal resistance （rs）, protein content and chlorophyll （Chl） conten...A greenhouse experlment was performed In order to Investigate the effects of dlfferent levels of water stress on leaf water potentlal （ψw）, stomatal resistance （rs）, protein content and chlorophyll （Chl） content of tomato plants （Lycoperslcon esculentum Mill. cv. Nlkita）. Water stress was Induced by addlng polyethylene glycol （PEG 6 000） to the nutrlent solution to reduce the osmotlc potential （ψs）. We Investlgated the behavlor of antl-oxldant enzymes, such as catalase （CAT） and superoxide dlsmutase （SOD）, durlng the development of water stress. Moderate and severe water stress （i.e. ψs= -0.51 and -1.22 MPa, respectlvely） caused a decrease In ψw for all treated （water-stressed） plants compared with control plants, wlth the reductlon belng more pronounced for severely stressed plants. In addltion, rs was slgnlflcantly affected by the Induced water stress and a decrease in leaf soluble protelns and Chl content was observed. Whereas CAT actlvlty remained constant, SOD actlvlty was increased in water-stressed plants compared wlth unstressed plants. These results Indicate the possible role of SOD as an anti-oxidant protector system for plants under water stress condltlons. Moreover, It suggests the possibllity of using this enzyme as an addltional screening crlterlon for detecting water stress in plants.展开更多
To know the annual water consumption of forest, it is necessary to acquire the annual transpiration value of stands. This paper is based on the data measured in the typical weather of the growth season, from 1998 to 2...To know the annual water consumption of forest, it is necessary to acquire the annual transpiration value of stands. This paper is based on the data measured in the typical weather of the growth season, from 1998 to 2000, with the LI 1600 Steady Porometer and the general weather information. The daily variation of transpiration in black locust forest ( Robinia pesudoacacia L.) is modeled by Penman Monteith equation. As a result of the model, a continuous daily transpiration in the growth season was calculated. The net radiation, intercepted by black locust forest canopy, was acquired from a semi empirical equation of measuring net radiation R n with the extinction coefficient k and leaf area index LAI . The canopy integral stomatic resistance is a mimesis with an empirical equation of measuring data. Compared with measuring data, the relative error of the modeled ones is less than 12% averagely. At last, the total transpiration of black locust forest during the period of 1998 and 2000 in the growth season of May to October, as an average transpiration of the different density stands, were 192 46, 187 07 and 195 59?mm respectively.展开更多
基金supported by the National Natural Science Foundation of China(30424813)Science Publication Foundation of the Chinese Academy of Sciences
文摘A greenhouse experlment was performed In order to Investigate the effects of dlfferent levels of water stress on leaf water potentlal （ψw）, stomatal resistance （rs）, protein content and chlorophyll （Chl） content of tomato plants （Lycoperslcon esculentum Mill. cv. Nlkita）. Water stress was Induced by addlng polyethylene glycol （PEG 6 000） to the nutrlent solution to reduce the osmotlc potential （ψs）. We Investlgated the behavlor of antl-oxldant enzymes, such as catalase （CAT） and superoxide dlsmutase （SOD）, durlng the development of water stress. Moderate and severe water stress （i.e. ψs= -0.51 and -1.22 MPa, respectlvely） caused a decrease In ψw for all treated （water-stressed） plants compared with control plants, wlth the reductlon belng more pronounced for severely stressed plants. In addltion, rs was slgnlflcantly affected by the Induced water stress and a decrease in leaf soluble protelns and Chl content was observed. Whereas CAT actlvlty remained constant, SOD actlvlty was increased in water-stressed plants compared wlth unstressed plants. These results Indicate the possible role of SOD as an anti-oxidant protector system for plants under water stress condltlons. Moreover, It suggests the possibllity of using this enzyme as an addltional screening crlterlon for detecting water stress in plants.
基金SupportedbytheNationalNaturalScienceFoundationofChina(39970 6 2 2 )andtheTeachingandResearchAwardProgramforYongCadremanTeachersinHigherEducationInstitutionsofMOE P .R .China
文摘To know the annual water consumption of forest, it is necessary to acquire the annual transpiration value of stands. This paper is based on the data measured in the typical weather of the growth season, from 1998 to 2000, with the LI 1600 Steady Porometer and the general weather information. The daily variation of transpiration in black locust forest ( Robinia pesudoacacia L.) is modeled by Penman Monteith equation. As a result of the model, a continuous daily transpiration in the growth season was calculated. The net radiation, intercepted by black locust forest canopy, was acquired from a semi empirical equation of measuring net radiation R n with the extinction coefficient k and leaf area index LAI . The canopy integral stomatic resistance is a mimesis with an empirical equation of measuring data. Compared with measuring data, the relative error of the modeled ones is less than 12% averagely. At last, the total transpiration of black locust forest during the period of 1998 and 2000 in the growth season of May to October, as an average transpiration of the different density stands, were 192 46, 187 07 and 195 59?mm respectively.
