Abstract
ABSTRACT
An increasing amount of reclaimed water is being used in turfgrass management; however, reclaimed water is often high in total dissolved salts and can result in salt stress injury and poor turf quality. The objectives of this study were to (i) determine the broad‐sense heritability estimate of salinity tolerance of 142 perennial ryegrass (Lolium perenne L.) genotypes and (ii) determine narrow‐sense heritability estimates and evaluate inheritance characteristics of salinity tolerance (heterosis, maternal effects, and combining ability) of progeny from crosses between fixed resistant and susceptible clones. Six replicates of each clone were irrigated overhead with a salt solution and were rated visually for percentage green color. The broad‐sense heritability estimate for salinity tolerance was 0.78, indicating that the majority of the phenotypic variation was due to genetic effects. A diallel cross between three salt‐tolerant and three salt‐sensitive parents was performed in 2006. Parents and progeny were established, irrigated overhead with a salt solution, and visually rated for percentage green in 2007 and 2008. Narrow‐sense heritability ranged from 0.72 (2007) to 0.66 (2008), indicating that the majority of the phenotypic variation was due to additive gene effects. No heterosis or maternal effects were found and general combining ability (GCA) accounted for more variance than specific combining ability (SCA). These results support the finding that salinity tolerance in perennial ryegrass is strongly controlled by additive gene effects. These data support a recurrent selection program that concentrates additive alleles as an effective breeding strategy to improve salinity tolerance in perennial ryegrass.