ÃÞ »¨ ѧ ±¨ Cotton Science 2010£¬22£¨3£©£º217-223
Somatic Embryogenesis and Plant Regeneration in Wild Cotton Species of G.tomentosum Abstract: The wild cotton species of G.tomentosum has some outstanding characters such as the higher resistance to pests and tolerance to drought. However, the upland cotton germplasm with the trait has not been obtained through sexual hybridization between G.hirsutum and G.tomentosum due to the distant relationship between the wild species and upland cotton. Protoplast fusion technique which depends on the success in the somatic culture of two different species can avoid sexual incompatibility. The callus inducing and somatic embryo germination of G.tomentosum were studied through the regulation of culture conditions such as plant growth regulators(PGRs), PEG, CuSO4 and AgNO3. The results indicated that under the same condition the frequency of somatic embryo germination and the plant regeneration ability of G.tomentosum were lower and the plant regeneration was more difficult than Coker 201. But through the regulation of culture conditions, we can get many embryoids and few of them converted to plantlets. The callus of G.tomentosum induced in the medium with the hormone combination of 0.1 mg¡¤L-1 KT + 0.1 mg¡¤L-1 2, 4-D held good for cell differentiation, and it was better for proliferation of the embryogenic callus in the medium with 0.5 mg¡¤L-1 IBA + 0.2 mg¡¤L-1 KT. The medium supplied with PEG was not helpful for initiation of somatic embryos. But the medium of MSB5 with 3.5 mg¡¤L-1 CuSO4+0.5 mg¡¤L-1 IBA + 0.2 mg¡¤L-1 KT, or 3 mg¡¤L-1 AgNO3+0.5 mg¡¤L-1 IBA+ 0.2 mg¡¤L-1 KT were good for the proliferation of embryogenic callus and germination of somatic embryo. This report provides an useful technique for somatic culture of the wild cotton species, and also ensures the protoplast fusion feasibly between these wild cotton species and other cotton species to centralize several good traits into a new germplasm. However, it is needed to study further about the various culture factors and conditions for building a quick and high efficient regeneration technique of G.tomentosum.
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