Physiological Factors Associated with Interspecific Variations in Drought Tolerance in Centipedegrass

Abstract

Drought stress is a critical abiotic factor that impedes plant growth and development, particularly in arid and semi-arid regions during summer. This study investigated the physiological mechanism of drought tolerance and post-drought recovery in two genotypes of centipedegrass (Eremochloa ophiuroides): the drought-resistant CG101 and the drought-sensitive CG021. The research studied the impacts of drought and subsequent rehydration on turf quality, leaf relative water content, electrolyte leakage rate (EL), photochemical efficiency (Fv/Fm), relative water loss rate (RWLR), and relative water uptake rate as well as the contents of proline, total soluble sugars, betaine, and leaf wax content (LWC) and the morphology of the root system. The findings revealed that the higher drought tolerance of CG101 was primarily associated with the superior cell membrane stability (lower EL), greater Fv/Fm, better water retention capacity (higher LWC and lower RWLR). In addition, the extensive root system of CG101, characterized by greater total root length and surface area, collectively contributed to the stronger drought tolerance of the drought-tolerant CG101 in comparison with the drought-sensitive CG021. During rehydration, the RWC of CG021 did not fully recover to the control levels mainly due to the reduced leaf Fv/Fm, LWC as well as the root length, root surface area, root volume, and the relatively weaker osmotic regulatory ability. This study provides insights into the physiological mechanisms resulting in interspecific variations in drought tolerance and post-drought recovery in centipedegrass, and offers theoretical support for breeding drought-resistant varieties in centipedegrass.

Keywords

• turfgrass
• centipedegrass
• drought tolerance
• physiological mechanism