| Pak. J. Bot., 36(2): 373-380, 2004. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
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GROWTH RESPONSE OF COTTON CULTIVARS TO ZINC DEFICIENCY STRESS IN CHELATOR-BUFFERED NUTRIENT SOLUTION MUHAMMAD IRSHAD, MAQSOOD AHMAD GILL*, TARIQ AZIZ, RAHMATULLAH AND IFTIKHAR AHMED
Abstract:
Growth response of eight cotton cultivars
to Zn stress was assessed in chelator-buffered nutrient solution. Pre-germinated
seedlings were grown in half strength modified Johnson's nutrient solution at
adequate and deficient levels of Zn. Zinc deficiency was induced by adding 50
µM di-ethylene tri-amine penta acetic acid (DTPA) in addition to all micronutrient
concentrations. Shoot and root growth for the various cotton cultivars was significantly
different at both levels of Zn supply in the growth medium. A typical Zn deficiency
symptom of inward curling of top leaves was evident in cotton cultivars grown
with chelator-buffered nutrient solution (Zn deficient). Two cotton cultivars
viz., FH-900 and VH-137, produced higher biomass and better Zn utilization. Zinc
concentration in cotton shoots grown at deficient level of Zn was less than its
critical concentration of 20 mg kg-1 which was several folds lower than its concentration
estimated for those grown at adequate Zn level. The study also depicted successful
induction of Zn deficiency in cotton in hydroponics by DTPA, indicating its suitability
for screening crop cultivars for micronutrient stress particularly for Zn deficiency.
Department of Soil Science, University
of Agriculture, Faisalabad, Pakistan. |
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