| en |
Re-watering: An effective measure to recover growth and photosynthetic characteristics in salt-stressed Brassica napus  L.
Javed, Qaiser; Wu, Yanyou; Xing, Deke; Azeem, Ahmad; Ullah, Ikram & Zaman, Muhammad
Abstract
Salinity is one of major environmental problem which is
limiting the agricultural production. This research was
conducted to evaluate the effect of re-watering on Brassica
napus L., and determination of an appropriate regime for
dilution of salted water by studying photosynthetic and
growth response of B. napus to salt stress and subsequent
re-watering. Plants were treated with NaCl (Nc1: 2.5, Nc2:
5, Nc3: 10; g L-1); Na2SO4 (Ns1: 2.5, Ns2: 5, Ns3: 10; g
L-1) and mixed salts treatments (M1: Nc1+ Ns3; M2: Nc3+
Ns1; M3: Nc2+ Ns2; g L-1) and 0 as control, followed by
re-watering. In salt stress phase, maximum reduction
in net photosynthetic rate (PN) was noted 79.54%,
80.72%, 84.54%, and 74.84% for Nc3, Ns3, M1 and M2,
respectively, under high concentration levels. To maintain
PN, carbonic anhydrase (CA) activity was stimulated
and kept water status stable under low (Nc1 and Ns1) to
medium concentration levels (Nc2, Ns2 and M3), and the
decreases in PN under Nc2, Ns2 and M3 were 48.28%,
55.58% and 58.69%, respectively. However, during rewatering
phase, growth and physiological parameters were
recovered well due to regulation of CA activity under low
to medium concentration levels. Relatively as compare to
other stress levels more recovery in PN was found after rewatering
under medium concentration levels, which were
44.94%, 53.45% and 63.04%, respectively. Though aimed
at consideration of high production in B. napus, the best
re-watering time was found to be when plants undergo
medium concentration levels. Therefore, this study
provides a new method for dilution of saline irrigation
based on plant physiology.
Keywords
Carbonic anhydrase activity; growth; re-watering; salt stress; photosynthetic traits
|
