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Pecan (Carya calhayensis Sarg.) For Walnut Branch pecan genus. Pecans and dried fruit is not only important woody oil trees, and is an important timber species and ecological economic species. Head, seedling propagation, grafting, propagation and cutting propagation is used mainly in the forestry production. Pecan zygotic embryos and material characteristics of zygotic embryo development, germination of zygotic embryos, somatic embryogenesis and somatic embryogenesis of the organization cytology content. The main findings are as follows .1. To study pecan zygotic embryo development characteristics, pecan zygotic embryo development experience globular embryo, heart-shaped embryo, the the torpedo embryo and cotyledon stage. 8-16 weeks zygotic embryos Determination of endogenous hormones results: GA3 and IAA was increased and then decreased, and reached the peak at 14 weeks were 11.3 ng · g-1FW 128.9 ng · g-1FW, followed by a gradual decline. ZR 10 weeks after the zygotic embryos natural pollination peak for 19.2ng · g-1FW, followed by a downward trend. ABA concentration has been on the rise. 8-10 weeks after natural pollination zygotic embryos embryogenic competent, under the right conditions easier to form callus and somatic embryos from callus indirect; natural pollination after 11-12 weeks of zygotic embryos, body The embryos are more prone cotyledon zygotic embryos components directly; zygotic embryos when zygotic embryo development time is 13-14 weeks after the natural pollination easier germination into seedlings. Pecan zygotic embryos as explants totipotency theoretical basis, embryogenic callus, somatic embryogenesis and the zygotic embryos sterile germination test. Compare the basic medium, growth regulator substances, carbon source and culture conditions, the germination of zygotic embryos and somatic embryogenesis. The results show that the pecan natural pollination after 8-10 weeks of zygotic embryos as explants, the somatic embryo indirect induced. Pecan indirect embryogenic callus induction basic medium 1/2MS, and additional 1.0mg · L-1BA, 0.01 mg · L-1 Picloram, 0.5 g · L-1CH, 20 g · L-1 glucose, 8.0 g · L-1 agar type. pH 5.7, 4 weeks subculture cycle is appropriate. Pecan direct select 11-12 zygotic embryos inoculated into modified WPM additional 1mg · L-1BA 1.0mg.L-12 ,4-D, 30 g L-1 sucrose, 6.0 g · L-1 phytgel , pH value of 5.7. Were cultured at 30 ° C in darkness, and then once every 2 turnover, six weeks statistics showed the best effect, somatic embryos directly incidence of 36.5%. Zygotic embryos aseptic germination of zygotic embryos of 14 weeks after the natural pollination, aseptic germination MS medium, growth regulators for 2mg.L-1BA 0.01mg.L-1piclaram additional 30 gL-1 glucose, 8.0 g · L-1 agar type A, pH value of 5.7. One week after inoculation dark culture, after one week, go to the light illumination cultivation, and the experimental results show that the medium best results, zygotic embryos sterile germination rate of 90.3%. 3 organization cytology method to study the origin and occurrence site pecan somatic embryos, pecan the somatic embryos multi occurred in zygotic embryo axes and cotyledons surface directly, somatic embryos after globular embryo, heart-shaped embryo, torpedo embryo and cotyledon and mature.
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