Heritability of terbacil herbicide tolerance in strawberry

Abstract

A partial diallel design was used to investigate the inheritance of tolerance to terbacil herbicide in cultivated strawberry, Fragaria xananassa Duch. Two tolerant cultivars, 'Honeoye' and 'Earliglow', two moderately tolerant cultivars, 'Lester' and 'Allstar', and two susceptible cultivars, 'Red Chief and 'Guardian' were used as parents to create populations that segregated for tolerance to the herbicide. Tolerance rankings of the populations closely coincided with expected rankings based on the published tolerance levels of parental cultivars. 'Honeoye' and 'Earliglow' derived populations had the highest average tolerance ratings, while 'Guardian' derived populations had the lowest tolerance ratings. Heritability was estimated at h2 = 0.50, indicating that significant progress in increasing the tolerance of new cultivars to terbacil can be achieved through traditional recurrent selection procedures. General and specific combining abilities suggest that the tolerant cultivars in this study may be fixed in their tolerance and that increased mean tolerance will be most apparent in progenies combining tolerant and susceptible cultivars. As such, a broader pool of germplasm may be needed to develop cultivars that are more tolerant than those in this study. Chemical names: terbacil (3-tert-butyl-5-chloro-6-methyluracil).