Plant water relations and canopy temperature depression for assessing water stress tolerance of potato

Abstract

An experiment was conducted with five potato genotypes at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during 2010–2011 under control and water stress conditions to determine the effect of water stress on plant water relations and canopy temperature depression of potato. Of the five genotypes, CIP 393371.58 and CIP 396244.12 maintained higher relative water content (RWC) under both the conditions and showed comparatively less midday depression in RWC. The water stress condition significantly decreased water uptake capacity. Under water stress condition tolerant genotypes CIP 393371.58 and CIP 396244.12 showed highest xylem exudation rate of 0.26 and 0.18 g h−1, respectively and transpiration rate of 36 and 34 µg m−2 s−1, respectively at 50 days after planting, and both were positively and significantly correlated. Greater increases in canopy temperature were observed at noon in Asterix and CIP 391004.18 and lower in CIP 393371.58 and CIP 396244.12 and showed inverse relationship with transpiration rate. The genotypes CIP 393371.58 and CIP 396244.12 showed higher canopy temperature depression value and the genotypes CIP 391004.18 and Asterix showed lower canopy temperature depression value under water stress condition. Among the genotypes, CIP 393371.58 and CIP 396244.12 showed better tolerance to water stress condition.