In vitro seed germination and seedling performance of Hibiscus coddii subsp. barnardii

Abstract

Hibiscus coddii subsp. barnardii is an endemic South African plant species with ornamental potential. The limited plant availability in nature and restrictions on the collection of living plant material (cuttings) for cultivation purposes, necessitated the development of a protocol for in vitro seed propagation to ensure all year round ex vitro establishment of plants. The effect of culture medium on seed germination and seedling performance was, therefore, studied. Various types of sterile seed cultures, namely moist filter paper bridges, five different strengths (¼, ½, ¾, full, 1¼) of PGR-free Murashige and Skoog medium (MS) and solid Gelrite® medium (control) were investigated. High germination percentages (85–98%) were found in all three seed cultures, although seeds germinated on filter paper, Gelrite® and lower strengths (¼, ½, ¾) of MS medium had shorter mean germination times (1.6–2.8 days) than those germinated on full and 1¼ strengths (3.5–4 days) of MS medium. Furthermore, the growth performance of seedlings varied with the strength of MS medium and was best supported on full strength MS medium, whereas ¼ and ½ strength MS media and Gelrite® cultures were detrimental for seedling growth.