Development of a model system for artificial seed production : I. encapsulation of somatic embryos by alginic = 인공종자 생산의 모델 시스템 개발 : I. 체세포배의 알진산에 의한 encapsulation

Abstract

In order to develop artificial seeds (encapsulated somatic embryos), suitability of gels as capsule materials for somatic embryos was determined by the ability of calcium alginate beads, approximately 3mm in diameter, to have sufficient sphericity, rigidity, retentivity of moisture for protection. The optimum encapsulation procedure was to mix embryos with sodium alginate (Sigma Type VI, 2-2.5%; Type VII, 3-3.5% w/v) and drop them individually into 50mM CaCl2 solution for 10 minutes. Excised embryos from true seeds of sweet potato were encapsulated as described above and then incubated on a filter paper moistened with distilled water in a Petri dish: 100% of them were germinated within 72 hours. The test verified that the capsule was nondamaging to the embryo and satisfied conditions for the minimum quality as an artificial seed coat. Embryogenic callus was induced on hypocotyl cuttings of carrot (Daucus carota L.; cv. Hong-shimohchon) seedlings cultured on Murashige and Skoog (MS) medium with lmg/￡ 2,4-D. Upon transfer to MS medium with 0.1-0.5mg/￡ kinetin and 0.02-0.2mg/￡ ABA, the callus gave rise to somatic embryos.

Encapsulated somatic embryos of carrot were incubated as described above: 60% of them germinated after one week and 98% of them after 2 weeks, while seeded on vermiculite, only 10% of them germinated even under almost 100% humidity conditions.