Authors: L Gratani R Catoni L Varone
Publish Date: 2011/03/10
Volume: 49, Issue: 1, Pages: 65-74
Abstract
Plant traits of Malcolmia littorea growing at the Botanic Garden of Rome and transplanted from the wild population developing along the Latium coast Italy were analyzed The highest photosynthetic rates P N 225 ± 05 μmolCO2 m−2 s−1 associated to the highest chlorophyll content Chl 60 ± 5 SPAD units and respiration rates R 111 ± 02 μmolCO2 m−2 s−1 were reached in spring when mean air temperature T m was in the range 17°C to 23°C P N Chl and R decreased by 86 38 and 59 in summer when mean maximum air temperature T max was 303 ± 26°C Leaf water potential decreased by 34 in summer compared to the spring value and it was associated to a relative water content RWC of 74 ± 4 and to a wateruse efficiency WUE of 215 ± 081 μmolCO2 mmol−1H2O Moreover also low air temperatures determined a significant P N and R decreases by 52 and 40 compared to the maximum respectively Responsiveness of gross photosynthetic rate P g to R was higher than that to P N as underlined by the slope of the regression line between the two variables The results underlined a low tolerance to both high and low air temperatures of M littorea The selected key traits R WUE Chl by the discriminant analysis might be used to monitor the M littorea wild population in the long time The ex situ cultivated plants could be propagated and used to increase the individuals number of the wild population
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