Back to Contents

Pak. J. Bot., 47(4): 1231-1239, 2015.

FREE FULL TEXT PDF

PROTECTION OF photosynthetic MACHINERY BY UP-REGULATION OF antioxidant enzymeS IN contrasting TOMATO  Genotypes UNDER DROUGHT

FAKHRA SHAMIM^1*, KHALIDA KHAN², HABIB-UR-REHMAN ATHAR³ AND ABDUL WAHEED⁴

Abstract: Current study was designed to evaluate the drought effect on some physiological and biochemical properties of tomato plants. Some native and exotic tomato genotypes were subjected to drought stress to investigate the effect on antioxidant enzymes and photosynthetic machinery. The tomato genotypes were exposed to different water regimes viz: 80, 60 and 40% of field capacity. Statistical analysis revealed significant interactions in some physiological parameters including transpiration rate (E), photosynthetic rate (A) and stomatal conductance (g_s). Drought stress enhanced the above properties in tolerant varieties like ‘L. pennellii’, ‘L. chilense’, ‘Lyallpur-1’ and ‘CLN1767’ in contrast to rest of the water stress sensitive genotypes. Moreover, same type of significant elevations were also observed when antioxidant enzymes like catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) were caloremitrcially quantified in drought tolerant tomato varieties. Overall, it was found that some tomato genotypes maintained their degree of water stress tolerance during their growth but with varying mechanism of water stress tolerance. Moreover, the above mentioned physiological and biochemical characteristics can act as valuable markers for selection and breeding programs for development of drought tolerant tomato genotypes.

Key words: Drought tolerance, Solanum lycopersicum, Stomatal conductance, Antioxidant enzymes.

^1,2Centre for Integrated Mountain Research, University of the Punjab, Lahore, Pakistan

³Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan

⁴COMSATS Institutes of Information Technology, Sahiwal, Pakistan

*Corresponding author e-mail: fakhra_dr@yahoo.co.uk