Drought stress affecting physio- biochemical characters and yield attributes in wheat (Triticum aestivum L.)

Abstract

Experiment was carried out to study the induced water stresses at different crop developmental
stages for physio-biochemical characters and yield attributes in two wheat cultivars at experimental
area of Division of Bio chemistry and Physiology, SKUAST- J, in 2013. The experiment was laid-out
with 02 wheat varieties i.e. PBW-343 and RSP-81 with 04 water stress levels. T1 (without withholding
of water), T2 (10 days with-holding of water [WOW]), T3 (15 days WOW) and T4 (20 days
WOW) were applied. Increased water stress significantly reduced the relative leaf water content
(RLWC), partitioning coefficient (PC) to spike, harvest index (HI), chlorophyll content, spike length,
number of grains/spike, weight of grains/spike and aphid incidence per spike in both wheat
varieties. About 55.8 and 54.6% reduction in RLWC was noticed at 20 days WOW in variety PBW-
343 and RSP-81, respectively as compared to control. PC to spike was reduced by 25.30 and 23.69%
at highest drought condition in variety PBW-343 and RSP-81 respectively in comparison to control.
Likewise, HI also reduced by 16.7 and 14% in variety PBW-343 and RSP-81, respectively. Chlorophyll
content decreased from 44.7 in control to 34.7 in 20 days WOW with variety PBW-343 and 37.8 in
control to 27.9 in 20 days WOW with RSP-81. Soluble sugar content increased significantly at
maximum WOW in both varieties while PBW-343 accumulates 37.9% of soluble sugar content in
comparison to control. Accumulation of proline was increased from 02 mg g–1 in control to 37.7 mg
g–1 at 20 days WOW in variety PBW-343. Spike length, grains per spike and weight of grains per
plant significantly decreased at maximum WOW in both varieties whereas the reduction was high
in variety PBW-343 than in RSP-81. Aphid population decreased with increasing the water stress
from 10 days WOW to 15 and 20 days WOW. Besides reduction in these parameters, RSP-81 showed
some resistance to water stress as compared to PBW-343.