Heritability of Salt Tolerance at Germination Based on Parent-Offspring Correlation and Selection Response in Barley (Hordeum vulgare L.)

Abstract

Heritability of salt tolerance in germinating seeds of barley (Hordeum vulgare L.) was estimated by parent-offspring correlation and selection response. Germination tests in 250 mM NaCl solution were conducted using the seeds of F₁, F₂, and F₃ plants (F₂, F₃, and F₄ generations, respectively) derived from the crosses between salt tolerant (OUJ417 and OUK666) and sensitive (OUE211) varieties. Salt tolerance of the two crosses showed polygenic segregations in F₂, F₃, and F₄ generations. Correlation coefficients between the parents and offsprings in two crosses were about 0.5 between F₂-F₃ generations and 0.6∼0.7 between F₃-F₄ generations. Realized heritabilities estimated from the ratio of (selection response)/(selection differential) were 0.2∼0.4 in the F₂-F₃ and 0.8∼0.9 in the F₃-F₄. Although dominant genetic variance of salt tolerance at germination is larger than additive genetic variance in the F₂ generation, heritability of this trait is relatively high even between F3-F4 generations and higher heritability may be obtained in lat-er generations. We have already selected highly salt tolerant barley varieties from over 6, 700 accessions, Using such genetic resources of salt tolerance as the parents, selection for increasing salt tolerance at germination may be carried out.