Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China.
J Plant Physiol. 2013 Sep 1;170(13):1202-11. doi: 10.1016/j.jplph.2013.03.019. Epub 2013 Jun 20.
Camellia nitidissima Chi (Theaceae) is a world-famous economic and ornamental plant with golden-yellow flowers. It has been classified as one of the rarest and most endangered plants in China. Our objective was to induce somatic embryogenesis, shoot organogenesis and plant regeneration for C. nitidissima. Three types of callus (whitish, reddish and yellowish) were induced from immature cotyledons on improved woody plant medium (WPM) with different plant growth regulators (PGRs). Among the callus, whitish callus was induced by 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and reddish and yellowish callus were induced by strongly active cytokinins, thidiazuron (TDZ) or 6-benzylaminopurine (BAP), singly or combined with weakly active auxin, α-naphthaleneacetic acid (NAA). The embryogenic callus could differentiate into somatic embryos, nodular embryogenic structures (large embryo-like structures) or adventitious shoots depending on the PGR used in WPM. BAP was best for adventitious buds and zeatin was best for somatic embryogenesis while kinetin (Kt) was best for the formation of nodular embryogenic structures. The three regeneration pathways often occurred in the same embryogenic callus clumps. Most shoots (80.0%) developed roots in WPM supplemented with 24.6 μM IBA and 0.3 μM NAA while 47.5% of somatic embryos could germinate directly and develop into plantlets on induction medium supplemented with 0.9 μM BAP and 0.1 μM NAA. The nodular embryogenic structures could be sub-cultured and cyclically developed in one of two differentiation pathways: shoot organogenesis or somatic embryogenesis. Plantlets derived from shoot buds rooted and somatic embryos germinated when transplanted into soil in a greenhouse; 66.7% of plantlets from shoot culture and 78.6% of plantlets from somatic embryos survived after 8 weeks' acclimatization.
金花茶（山茶科）是一种世界闻名的经济和观赏植物，具有金黄色的花朵。它已被列为中国最稀有和最濒危的植物之一。我们的目标是诱导金花茶的体细胞胚胎发生、芽器官发生和植株再生。从改良的木本植物培养基（WPM）中不同植物生长调节剂（PGRs）诱导的未成熟子叶中诱导出三种类型的愈伤组织（白色、红色和黄色）。在这些愈伤组织中，白色愈伤组织由 4.5 μM 2,4-二氯苯氧乙酸（2,4-D）诱导，红色和黄色愈伤组织由强活性细胞分裂素噻唑隆（TDZ）或 6-苄氨基嘌呤（BAP）单独或与弱活性生长素α-萘乙酸（NAA）组合诱导。胚性愈伤组织可根据 WPM 中使用的 PGR 分化为体细胞胚、结节状胚性结构（大胚状结构）或不定芽。BAP 最适合不定芽，玉米素（zeatin）最适合体细胞胚胎发生，而激动素（Kt）最适合结节状胚性结构的形成。这三种再生途径经常发生在同一胚性愈伤组织块中。大多数（80.0%）芽在 WPM 中添加 24.6 μM IBA 和 0.3 μM NAA 后生根，而 47.5%的体细胞胚可直接在添加 0.9 μM BAP 和 0.1 μM NAA 的诱导培养基中发芽并发育成小植株。结节状胚性结构可在两种分化途径之一中进行继代培养和周期性发育：芽器官发生或体细胞胚胎发生。从芽培养中衍生的小植株生根，从体细胞胚中衍生的小植株发芽，当移栽到温室中的土壤中时；从芽培养中获得的小植株中有 66.7%和从体细胞胚中获得的小植株中有 78.6%在 8 周的适应期后存活。
