Heritability of Creeping Bentgrass Shoot Water Content under Soil Dehydration and Elevated Temperatures

Abstract

Improvement of resistance to heat and moisture stress in creeping bentgrass (Agrostis stolonifera var. palustris Huds.) would enable increased planting and use in warmer environments. The objectives of these studies were to: (i) determine the association of shoot water content with survival of creeping bentgrass under elevated soil temperatures, (ii) estimate the heritability of shoot water content in creeping bentgrass, and (iii) determine the relationship of shoot water content under soil temperature stress with shoot water content under soil dehydration stress. ‘Seaside’ creeping bentgrass plants and plants selected from Seaside (Population A) that survived soil temperature stress were subjected to soil temperature stresses ranging from 29 to 37 °C for 4 wk. Water content, measured as (wet weight — dry weight)/ dry weight) of shoot tissue, was found to be 10% higher in the Population A plants. Ten parental clones of creeping bentgrass and 20 half‐sib progeny of each were exposed to 1, 2, 4, and 6 wk of soil temperature stress. Parent and progeny were significantly correlated in water content under soil temperature stress after 2 and 4 wk. Canopy temperature of the 10 parental clones of bentgrass was significantly correlated with water content under soil temperature stress. Narrow‐sense heritability of water content of shoot tissue was estimated between 0.98 and 1.0 using parent‐progeny regression in these creeping bentgrass populations.