HERITABILITY OF CREEPING BENTGRASS SHOOT WATER-CONTENT UNDER SOIL DEHYDRATION AND ELEVATED-TEMPERATURES

Improvement of resistance to heat and moisture stress in creeping bent grass (Agrostis stolonifera var. palustris Huds.) would enable increas ed planting and use in warmer environments. The objectives of these st udies were to: (i) determine the association of shoot water content wi th survival of creeping bentgrass under elevated soil temperatures, (i i) estimate the heritability of shoot water content in creeping bentgr ass, and (iii) determine the relationship of shoot water content under soil temperature stress with shoot water content under soil dehydrati on stress. 'Seaside' creeping bentgrass plants and plants selected fro m Seaside (Population A) that survived soil temperature stress were su bjected to soil temperature stresses ranging from 29 to 37-degrees-C f or 4 wk. Water content, measured as (wet weight - dry weight)/dry weig ht) of shoot tissue, was found to be 10% higher in the Population A pl ants. Ten parental clones of creeping bentgrass and 20 half-sib progen y of each were exposed to 1, 2, 4, and 6 wk of soil temperature stress . Parent and progeny were significantly correlated in water content un der soil temperature stress after 2 and 4 wk. Canopy temperature of th e 10 parental clones of bentgrass was significantly correlated with wa ter content under soil temperature stress. Narrow-sense heritability o f water content of shoot tissue was estimated between 0.98 and 1.0 usi ng parent-progeny regression in these creeping bentgrass populations