The inheritance of alcohol dehydrogenase isozymes in seeds of hexaploid Echinochloa crus-galli Beauv.

Abstract

To clarify the mode of inheritance of alcohol dehydrogenase (ADH) isozymes in Echinochloa crus-galli, we induced single-banded mutant lines for ADH by gamma-ray irradiation; the irradiation of the 5-banded E. crus-galli var. formosensis (phenotype A₁A₂A₃A₄A₅) produced two single-banded mutant lines, A₁ and A₅. All pairwise reciprocal crosses were made among the single-banded mutant lines and the naturally occurring single-banded type E. crus-galli var. praticola that displays only band A₃. The ADH zymograms from the resulting F₁ progenies were identified by polyacrylamide gel electrophoresis and the relative staining densities of the bands were determined by densitometer scanning for several important E. crus-galli phenotypes and F₁ individuals. All F₁ seeds displayed both parental bands plus an additional band located intermediate to the parental bands. Moreover, the ratios of the band densities were in agreement with those expected from the kinetics of ADH dimer formation. The results can be accounted for by three loci encoding three ADH subunits. Also, the data indicate that the A₃ band of the 5-banded phenotype consists of two different dimeric products, homo- and hetero-dimers.