Inheritance of Photoperiod Sensitivity, Hirsute Seed, and Albinism in Okra

Abstract

Abstract Photoperiod-sensitive (short day) plants were found in okra [Abelmoschus esculentus (L.) Moench] PI 291124. These plants did not flower at Charleston, S.C., until mid-October. Segregation of populations derived from crosses with ‘Clemson Spineless’ (CS) indicated that photoperiod sensitivity was conditioned by a single recessive gene. Inheritance of hirsute seed, found in PI 172677, was determined by 2 separate genetic systems. The F1 of PI 172677 (hirsute) × ‘C S’ (glabrous) had hirsute hila and glabrous testae. In the F2, when data from seed parts were analyzed separately, hirsute hila was conditioned by 2 dominant genes, and glabrous testae was conditioned by 2 other dominant genes. When data on both seed parts were combined and independent assortment was assumed, 4 expected phenotypes were missing in the F2. Indirect evidence from the F2 and backcross populations indicated that there were linkages among the alleles which determine presence or absence of trichomes on okra seed. The possible linkage groups are described. An albino mutant, found in progeny of irradiated ‘CS’, was conditioned by a single recessive gene. The gene symbols sd and a are proposed for the genes conditioning the short day response and the albino mutant, respectively; the genes conditioning hirsute seed will not be named until linkage relationships can be resolved.