|
Influence of
soil drought stress on photosynthesis, carbohydrates and the
nitrogen and phophorus absorb in different section of leaves
and stem of Fugi/M.9EML, a young apple seedling
Zhang Jie1, Yao Yuncong1*,
John G. Streeter2 and David C. Ferree2
1Department
of plant science and technology, Beijing University of
Agriculture, Beijing, 102206 China.
2Department
of Horticulture and Crop Science, Ohio State University and
OARDC,1680 Madison Avenue, Wooster, Ohio 44691 USA.
*Corresponding author. E-mail:
yaoyc_20@126.com.
Abbreviations: ET,
Evapotranspiration; Pn, photosynthesis; E,
transpiration; RWC, relative water content;
DPS, data processing system.
Accepted 28 July, 2010 |
|
Drought is the most significant limiting factor for plant
cultivation. Greenhouse-grown 1-year-old potted M.9EMLA
apple trees (Malus domestica Borkh.) (after growing
for 6 weeks) were subjected to drought stress by withholding
water for an additional six-week period. The photosynthesis,
carbohydrates and the nitrogen (N), phosphorus (P) absorb in
the upper, middle and lower leaves of the seedlings were
determined. The results revealed that drought stress
obviously decreased the photosynthesis and carbohydrates
contents in the leaves at all sections of shoot compared
with the control. Sorbitol and glucose concentrations
increased over time and was kept at a higher level during
the drought stress period whereas sucrose concentration
declined. N content in the leaves kept a flat trend and was
higher than that of the control while P concentration
decreased compared with the control. These results
demonstrated that drought stress prevented N and P
absorbtion and decreased RWC of apple leaves, which caused
the decline of photosynthesis and transpiration. Thus, the
direct phenotype was the slowed growth which was
specifically expressed in decreased plant height, number of
leaves, average leaf area and stem diameter.
Key words:
Malus domestica Borkh, sorbitol, water
deficit, transpiration. |
