Abstract

Haemanthus albiflos (Amaryllidaceae) is a monocotyledonous plant with high ornamental value. To increase the ornamental value of this species, polyploidy breeding was programmed in this study by employing endosperm culture for producing triploid plants. Further, we tried to produce hexaploid plant by colchicine treatment to endosperm-derived callus. As an initial step, endosperm explants harvested 8 weeks after flowering were cultured on Murashige and Skoog (MS) medium containing 5 mg L⁻¹ 4-amino-3,5,6-trichloropicolinic acid (picloram) and 5 mg L⁻¹ 6-benzylaminopurine (BAP) for callus induction. Induced calli were maintained on the same medium. Somatic embryos and adventitious shoots were observed after transfer the callus segments onto 1/2MS medium without plant growth regulators (PGRs). Further development of somatic embryos and adventitious shoots were achieved by transferring the callus segments onto 0.5 mg L⁻¹ 1-naphthaleneacetic acid (NAA) and 1 mg L⁻¹ BAP. Complete plantlets were established after placing the regenerated shoots and developing embryos on 1/2MS medium without PGRs. Flow cytometric analysis revealed that diploid, triploid, and tetraploid plantlets were involved in these regenerants. When the endosperm-derived callus segments were treated with 0.2% (w/v) colchicine for 24, 48, and 72 h, 4 hexaploid plants were regenerated through the same regeneration procedures as mentioned above. Ploidy levels of the representative diploid, triploid, and hexaploid plants were also confirmed by counting chromosome numbers. Availability of endosperm culture in combination with colchicine treatment was discussed as the means for producing polyploid plants.

Graphic abstract

中文翻译：

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二倍体白花菊通过胚乳培养和秋水仙碱处理同时生产三倍体和六倍体植物

摘要

Haemanthus albiflos（Amaryllidaceae）是具有较高观赏价值的单子叶植物。为了增加该物种的观赏价值，在这项研究中通过使用胚乳培养来生产三倍体植物，对多倍体育种进行了编程。此外，我们试图通过秋水仙碱处理对胚乳衍生的愈伤组织产生六倍体植物。作为第一步，将花后8周收获的胚乳外植体在含有5 mg L ^-1 4-氨基-3,5,6-三氯吡啶甲酸（picloram）和5 mg L ^-1的Murashige和Skoog（MS）培养基上培养用于诱导愈伤组织的6-苄氨基嘌呤（BAP）。诱导的愈伤组织保持在相同的培养基上。将愈伤组织片段转移到没有植物生长调节剂（PGR）的1 / 2MS培养基上后，观察到体细胞胚和不定芽。通过将愈伤组织片段转移到0.5 mg L ^-1 1-萘乙酸（NAA）和1 mg L ^-1上，体细胞胚和不定芽的进一步发育BAP。在没有PGRs的1 / 2MS培养基上放置再生芽和发育胚后，建立完整的幼苗。流式细胞仪分析表明，二倍体，三倍体和四倍体小苗参与了这些再生剂。当将胚乳来源的愈伤组织片段用0.2％（w / v）秋水仙碱处理24、48和72小时时，通过与上述相同的再生程序再生了4种六倍体植物。代表性的二倍体，三倍体和六倍体植物的倍性水平也可以通过计算染色体数目来确定。讨论了与秋水仙碱处理结合使用胚乳培养物作为生产多倍体植物的方法。

图形摘要