Waterlogging Tolerance of Kentucky Bluegrass Cultivars

Abstract

Waterlogging (WL) affects the growth and physiological responses of turfgrass. The objectives of this study were to compare the relative WL tolerance of Kentucky bluegrass (Poa pratensis L.) cultivars and to investigate the physiological responses of shoots and roots to WL. Ten cultivars differing in growth habit were subjected to 30 d of WL. The turf quality (TQ) and soil redox potential (Eh), as well as the chlorophyll concentration (Chl), decreased with increasing periods of WL. Among all cultivars, root dry weight (RDW) decreased 16.7% to 39.9% under 10 d and 30.0% to 60% under 30 d of WL, respectively. Waterlogging increased the root electrolyte leakage (REL) from 0.6% to 53.2% under 10 d and from 29.1% to 98.0% under 30 d of WL for all cultivars, respectively. The best correlations were observed between Eh and TQ (r = 0.74), REL and TQ (r = 0.75), RDW and root water-soluble carbohydrate content (RWSC) (r = 0.74), and root oxidase activity and RWSC (r = 0.63), respectively. ‘Moonlight’, ‘Serene’, and ‘Champagne’ showed better tolerance to short-term WL conditions, whereas ‘Kenblue’ and ‘Eagleton’ were the least tolerant cultivars. ‘Limousine’, ‘Unique’, ‘Awesome’, ‘Julia’, and ‘Midnight II’ ranked in the middle group. Variations in WL tolerance among Kentucky bluegrasses could potentially be used for enhancing turfgrass management.