Inheritance of Persistent-Green Color in Asparagus Officinalis, L.

Abstract

Two mature, dark-green asparagus plants (one female and one male) termed "persistent-green" were selected in a New Jersey asparagus field on November 11, 1959, when the other plants were yellow or brown. The two persistent-green plants were crossed; each of them was crossed also with normal plants for the genetic study of this character. A secondary part of this study was to determine the effect of the color gene or genes on the plant-pigment system by means of spectrophotometric analyses. An attempt also was made to identify the persistent-green mutants in the seedling stage. The study of the phenotypes of 17 F₁, F₂, and reciprocal BC₁ progenies indicated that persistent-green color in asparagus is inherited as a single recessive gene. There was a large quantitative difference in chlorophyll and carotene between the persistent-green and normal plant complexes in October, but not in July. Apparently the persistent-green mutants retain chlorophyll and carotene much later in the season than do the normal plants. No qualitative difference in pigment was found in either July or October. Asparagus seedlings were easily classified as to persistent-green (green foliage) or normal (yellow foliage) in the greenhouse when the plants were 6 weeks old.