Alcohol Dehydrogenase Zymogram, Its Inheritance and Anaerobic Germinability of Seeds of Echinochloa Weeds

Abstract

Seed polymorphism of Echinochloa weeds in alcohol dehydrogenase (ADH), which has a critical function for the paddy weeds to germinate under flooding, was studied in the 196 individual accessions of the paddy and upland weeds collected in natural populations. The ADH zymograms detected in seeds were highly polymorphic and classified into five types; A₃, A₁A₂A₃, A₁A₃A₅, A₃A₄A₅ and A₁A₂A₃A₄A₅. The majority of each species and varieties had a specific zymogram; E. oryzicoloa, A₁A₂A₃; E. crus-gall var. formosensis, A₁A₂A₃A₄A₅; E. crus-gell var. praticoloa. A₃. E. crus-galli var. crus-galli having a widespread habitat had somewhat varied zymograms. The F₁ seeds obtained from reciprocal crosses between E. crus-galli var. formosensis (A₁A₂A₃A₄A₅, a paddy weed) and var. praticola (A₃, an upland weed) had A₁A₂A₃A₄A₅, and the observed segregation ratios of the F₂ seeds derived by selfing F₁ plants fitted to the two gene segregation mode of 9:3:3:1 for A₁A₂A₃A₄A₅:A₁A₂A₃:A₃A₄A₅:A₃. No distinct relationship was found between anaerobic seed germinability and ADH zymograrns of Echinochloa weeds collected in the natural populations. None of the accessions with A₃, however, showed anaerobic germinability whereas the others with either A₁A₂A₃ or A₁A₂A₃A₄A₅ did in E. crus-galli var. praticola.