DROUGHT TOLERANCE OF Leucophyllum frutescens: PHYSIOLOGICAL AND MORPHOLOGICAL STUDIES REVEAL THE POTENTIAL XEROPHYTE

Abstract

Xeriscaping focus on the use of drought tolerant species of plants for environmental sustainability leading to the conservation of natural resources. We need to look for drought tolerant, water efficient plant species. Present research was aimed to assess the water use efficiency of Leucophyllum frutescens (silvery) for its adaptability and potential as xerophyte. In this study, seven treatments were applied were 100% field capacity was considered as control while 85%, 70%, 55%, 40%, 25% and 5% field capacities were taken as different drought levels. Effect of drought commenced at 40% field capacity and lower drought treatments as decrease in shoot and root fresh and dry weight, root length, leaf area and leaf area index and leaf firing percentage increased with severity of drought compared to 100% field capacity. Physiological parameters including water use efficiency (A/E), leaf water potential (yleaf), stomatal conductance (gs), photosynthesis rate, cell membrane stability and total chlorophyll contents proved that this plant species can tolerate severe drought conditions. Positive correlation was found among most of the attributes but leaf temperature was negatively correlated with leaf water potential, photosynthesis rate, cell membrane stability, and chlorophyll contents. Moreover, regression analysis between various morphological and physiological attributes showed the predictive power of the model yielding significant results for leaf area and cell membrane stability (R2 = 0.74), root length and photosynthesis rate (R2 = 0.65), leaf temperature and chlorophyll contents (R2 = 0.43) and leaf area and leaf water potential (yleaf) (R2 = 0.93).

Keywords

• cell membrane stability
• field capacity
• leaf area index
• Leucophyllum frutescens
• photosynthesis rate
• stomatal conductance