Induction of somatic embryogenesis in Pinus caribaea. (Special Issue: Tree micropropagation and tissue culture.)

摘要

Brassinosteroids are of ubiquitous occurrence in plants and elicit a wide spectrum of physiological responses including somatic embryogenesis in conifers. This study highlights the successful brassinolide-mediated stimulation of embryogenesis in all the five genotypes of Pinus caribaea tested. 24-epiBrassinolide at 2.0 micro M with 9.0 micro M 2, 4-dichlorophenoxy acetic acid enhanced the formation of embryogenic tissue from mature zygotic embryos on half-strength MSG basal medium. However, the frequency of somatic embryogenesis was not similar in all the five genotypes tested. The highest percentage of somatic embryogenesis (87.0+or-1.8) was recorded in PC 05 genotype. On the other hand the lowest percentage of somatic embryogenesis (70.0+or-1.7) was obtained in PC11 genotype. The developed somatic embryos on maturation medium after 12 to 14 weeks in all the five genotypes tested. Therefore, 24-epiBrassinolide can be used as growth regulator in conifer somatic embryogenesis for improving the initiation of embryogenic cultures of recalcitrant pines for the commercial forestry programmes particularly in Indian subcontinent.