利用桑树特异种质资源的冬芽组织培养再生植株的试验

Plant Regeneration from Winter Bud Cultures of Special Mulberry Germplasm Resources

以不同类型的桑树特异种质资源的冬芽为材料,分别在含有不同种类生长调节剂及添加量的培养基中培养诱导桑树再生植株,考察桑树特异种质资源利用冬芽培养再生植株的可行性,筛选适宜的生长调节剂及其用量。结果表明:供试桑树种质资源的冬芽在不添加生长调节剂的培养基中外植体停止生长,添加生长激素TDZ能较好地诱导和促进愈伤组织的形成与生长,但会抑制生长芽的再生长,而添加细胞分裂素6-BA能促进冬芽的再生,且添加3.0 mg/L 6-BA的培养基中冬芽再生率显著高于添加1.0 mg/L 6-BA的培养基;8份桑树种质资源的冬芽在含3.0 mg/L 6-BA的改良培养基中培养,新疆药桑和小花叶皮桑的丛生芽诱导率最高,其冬芽的再生率均为66.7%,滇桑次之,再生率为55.5%,天目山桑和斯里兰卡的再生率分别为40.0%和25.0%;5份桑树种质资源的冬芽再生组培苗转移至生根培养基中培养1个月后,只有滇桑和新疆药桑分别诱导出再生根系(诱导率为分别为20.0%、14.3%)后移栽成活。研究结果初步显示,离体组织再生培养是保存和利用天然22倍体新疆药桑、渐危种滇桑等珍稀桑树种质资源的有效途径之一。

In order to examine the feasibility of using winter buds of special mulberry germplasm resources to regenerate plantlets and screen suitable growth regulators and appropriate contents in culture medium, winter buds of different spe- cial mulberry germplasm resources were cultured on media containing various kinds and amounts of growth regulators and were induced to regenerate mulberry plantlet. The results showed that the winter buds of tested mulberry germplasm resources stopped growing on media not supplemented with growth regulators. Growth hormone TDZ supplemented in the media could induce callus formation and growth but inhibited bud growth. Cytokinin 6-BA supplemented in the media promoted bud regeneration and the rate of winter bud regeneration on medium containing 3.0 mg/L 6-BA was signifi- cantly higher than that on medium containing 1.0 mg/L 6-BA. Among the 8 mulberry germplasm resources whose winter buds were cultured on media containing 3.0 mg/L 6-BA, Xinjiang Yaosang and Xiaohuaye Pisang had the highest indu- cing rate of clustered buds with winter bud regeneration rate up to 66.7%. Diansang took the second place with winterbud regeneration rate of 55.5%. Tianmushan Sang and Sri Lanka had winter bud regeneration rate of 40.0% and 25.0% respectively. One month after winter-bud-regener- ated shoots of 5 mulberry germplasm resources were transferred onto rooting medium, only shoots of Xinjiang Yaosang and Diansang formed root system （the induction rate was 20.0% and 14.3% respectively） and survived after being transplanted into soil. These results preliminarily showed that in vitro tissue culture and plant regeneration is an ef- fective method to conserve and utilize rare and endangered mulberry germplasm resources such as Diansang and Xinjiang Yaosang （a natural 22-ploid species）.