Picloram induced somatic embryogenesis in Gasteria and Haworthia

Abstract

Various leaf sections of Gasteria verrucosa Haw. and Haworthia fasciata Haw. were cultured on media to examine the effect of picloram (4-amino 3, 5, 6-trichloropicolinic acid) and 2, 4-D (2, 4-dichlorophenoxy acetic acid) on somatic embryogenesis. Picloram (0.5, 1.0, 2.0, 3.0mg1-1 ) outperformed 2,4-D (0, 1.0, 2.0, 3.0mg1-1 ) as the auxin source of both earliness of callus and embryo induction and final yield of embryos produced at both kinetin levels examined (0.25, 1.0mgl -~ ). Embryos arose initially as a yellow, compact globular masses from the area just beneath the epidermis in linear pattern parallel with the main axis of the leaf and then developed a heartshaped appearance. Embryo formation was preceded by growth of callus almost crystalline in appearance on the cut surface. Subsequent shoot formation developed from green pigmented loci in crystalline callus derived from embryos. Shoot and root development in Gasteria was induced on a defined medium containing quarter strength MS or B5 salts with no hormonal supplementation.

Organogennsis and Somatic Embryogenesis from Young Flower Buds of Agapanthus africanus Hoffmanns.

“…In Agapanthus africanus, however, somatic embryogenesis was not induced by 2, 4-D but by picloram. The effectiveness of picloram for inducing somatic embryogenesis has also been reported in some other monocotyledonous plants [10,11] as well as some dicots such as pea [12] and chickpea [13]. Because of the high ability in regeneration and multiplication, the plant regeneration systems of agapanthus established in the present study will be efficiently used for rapid clonal propagation if the micropropagated plants have no aberrant somaclonal variations.…”

Induction of somatic embryos in pea, Pisum sativum L.

“…In contrast to previous experiments, where somatic embryogenesis was attempted by transfer of pea cells or callus to hormone-free media (Jacobsen, unpublished results), the transfer of callus tissues to liquid media with low picloram concentration was successful, thus confirming the suggestions of others [2,5] that lower concentrations of picloram might be advantageous. Although the embryos in the present study were not derived from free single cells or micro clusters but from embryoids formed at the surface of callus tissues, their occurrence proves the general ability of pea, and possibly other seed legumes, to form somatic embryos.…”

Regeneration of haploid plants from anther cultures of the Asiatic hybrid lily ‘Connecticut King’

“…It has already been reported that picloram gave better results than 2,4-D for both callus induction and subsequent morphogenesis in several Liliaceous species: somatic embryogenesis from leaf sections of Gasteria and Haworthia (Beyl and Sharma, 1983), and callus formation and plant regeneration from shoot tips of Allium cepa (Phillips and Luteyn, 1983). The present study showed for the first time that picloram had beneficial effects on haploid induction in anther cultures of Lilium species.…”