Study some of Morphological and Physiological Traits of Kurrajong Brachychiton populneus (Schott & Endl.) Seedlings Planted under Water Stress Conditions

Abstract

In this study, Brachychiton populneus seedlings were subjected to drought stress for 90 Days and physiological and morphological characters analyzed to determine their response to water deficit. The growth characters including, height and diameter of shoots, the dry weight of shoots and roots as well as photosynthetic pigment and the leaves content of relative water content were measured to evaluate the effects of drought in the physiological growth of plant. The lowest means; 59 cm and 8 mm of shoot height and diameter respectively were recorded at 30% of water holding capacity of soil (WHC). Drought treated seedlings at both 60% and 30% WHC had lower dry weight of shoots; 9.54 and 8.24 g plant-1 respectively compared to the control. Consequently, the increase of drought conditions led to enhancement the growth of roots and roots to shoots ratio. The highest increase in the dry weight of roots and roots to shoots ratio were25.96 g plant-1 and 3.19 recorded under severe drought stress condition. Lowest amount of chlorophyll a; 2.94 mg g-1 F W recorded under 30% SWHC. It is found also the total content of chlorophyll in the leaves decreased significantly; 5.86 and 7.88 mg g-1 F W under both levels. While the highest ratio of chlorophyll a: b was 1.59 recorded at 60% SWHC. However, the lowest leave relative water content LRWC%; 86% was recorded under 30% SWHC. These findings may explain the characters of the early growth and physiological responses of, Brachychiton populneus to dehydration and facilitate the selection of drought-resistant tree families.