The chlorophyll fluorescence parameters of Kobresia humilis Serg. and Polygonum viviparum L. grown at two different altitudes (3?200 m, 3?980 m) were measured and the ultrastructure of chloroplasts were observ...The chlorophyll fluorescence parameters of Kobresia humilis Serg. and Polygonum viviparum L. grown at two different altitudes (3?200 m, 3?980 m) were measured and the ultrastructure of chloroplasts were observed for studying the photosynthetic adaptability of plants to the influences of stress conditions in alpine environment. Rfd _values, the vitality index, in leaves of K. humilis and P.viviparum grown at 3?980 m were higher than those at 3?200 m. The higher ratio of F v/F o and F v/F m in leaves of K. humilis and P.viviparum indicated that the rate of photosynthetic conversion of light energy increased at higher altitude. Ratios of F v/F o and F v/F m and Rfd _values in K.humilis were higher than that in P.viviparum grown at the same altitude. There were more irregular chloroplasts in leaves of both species grown at higher altitude. Many irregular chloroplasts such as swollen thylakoid, deformed chloroplast envelope, were observed in P.viviparum grown at 3?980 m, but few in K. humilis . These results were discussed in relation to the photosynthetic adaptability of alpine plants and the different adaptive competence between K.humilis and P.viviparum .展开更多
文摘The chlorophyll fluorescence parameters of Kobresia humilis Serg. and Polygonum viviparum L. grown at two different altitudes (3?200 m, 3?980 m) were measured and the ultrastructure of chloroplasts were observed for studying the photosynthetic adaptability of plants to the influences of stress conditions in alpine environment. Rfd _values, the vitality index, in leaves of K. humilis and P.viviparum grown at 3?980 m were higher than those at 3?200 m. The higher ratio of F v/F o and F v/F m in leaves of K. humilis and P.viviparum indicated that the rate of photosynthetic conversion of light energy increased at higher altitude. Ratios of F v/F o and F v/F m and Rfd _values in K.humilis were higher than that in P.viviparum grown at the same altitude. There were more irregular chloroplasts in leaves of both species grown at higher altitude. Many irregular chloroplasts such as swollen thylakoid, deformed chloroplast envelope, were observed in P.viviparum grown at 3?980 m, but few in K. humilis . These results were discussed in relation to the photosynthetic adaptability of alpine plants and the different adaptive competence between K.humilis and P.viviparum .