|
|
|
Seasonal variation in water relations of
desert shrubs from Karachi, Pakistan
M.
Ajmal Khan and N. Beena
Abstract:
Seasonal variation in
water potential, stomatal conductance. chlorophyll a and b, and proline
content were measured in both young and old leaves of three desert
species viz., Calotropis procera, Senma Izolosevicea and Aerva
javanica. Water status of young and old leaves showed similar
pattern of seasonal fluctuation in all species studied. With an increase
in water stress water potential and xylem pressure potential became more
negative. Stomata1 conductance was highest in July when humidity was the
highest. Overall chlorophyll b concentration of was higher in comparison
to chlorophyll a. Proline concentration showed a peak during August and
September. Lack of rainfall caused reduction of water potential and
water evaporation with a corresponding decrease in proline content. |
|
|