ZHANG Ting1, CAO Yang2. Effects of Drought Stress on Non-structural Carbohydrates of Robinia pseudoacacia Saplings at the End of the Growing Season[J]. 2016, 30(5): 297-304.
DOI:
ZHANG Ting1, CAO Yang2. Effects of Drought Stress on Non-structural Carbohydrates of Robinia pseudoacacia Saplings at the End of the Growing Season[J]. 2016, 30(5): 297-304. DOI: 10.13870/j.cnki.stbcxb.2016.05.049.
Effects of Drought Stress on Non-structural Carbohydrates of Robinia pseudoacacia Saplings at the End of the Growing Season
One-year-old Robinia pseudoacacia saplings were subjected to 70% of field capacity (control) and progressive drought stress (treatment) to study the effects of drought stress on non-structural carbohydrates (NSCs) of R. pseudoacacia saplings at the end of the growing season. While leaf biomass
stomatal conductance and net photosynthetic rates of saplings under control generally exhibited no significant differences throughout the experiment (P<0.05)
those under treatment decreased with the intensification of drought stress (P<0.01). Soluble sugar concentrations and the ratios of soluble sugars to starch in different tissues under treatment all increased with drought progression
but were significantly higher than those under control (P<0.05). Contrarily
starch and NSC concentrations in each tissue under treatment all decreased with drought progression (P<0.05). Except NSC in leaves and fine roots
starch and NSC concentrations under treatment were all lower than those under control (P<0.05). NSC concentrations in branches
stems and coarse roots were 96.6%
70.5%
and 78.2% of those under control
respectively. At the whole sapling level
NSC concentrations under treatment decreased throughout the experiment
and were significantly lower than those under control (P<0.05)
and were 84.0%
79.0%
76.3% and 67.5% of those under control on the 6th
9th
12th and 15th days
respectively. Soluble sugar
starch and NSC concentrations and the ratios of soluble sugars to starch in different sapling tissues
except NSC concentrations in branches and fine roots
and NSC concentrations at the whole sapling level were all significantly correlated with soil water content
leaf biomass
stomatal conductance and net photosynthetic rates. Our results suggested that the premature defoliation and decrease of photosynthetic rate of R. pseudoacacia saplings resulted from drought stress at the end of the growing season could facilitate the transformation of starch to soluble sugars and then decrease the accumulation of starch
as a result
would induce the premature consuming of NSC
which would mainly occur to stems and coarse roots.