Sherif N Ahamed, Senthil Kumar T, Rao M V
PG and Research Department of Botany, Jamal Mohamed College (Autonomous), Affiliated to Bharathidasan University, Tiruchirappalli, 620020 Tamil Nadu India.
Department of Botany, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024 Tamil Nadu India.
Physiol Mol Biol Plants. 2020 Dec;26(12):2391-2405. doi: 10.1007/s12298-020-00917-9. Epub 2020 Dec 24.
is a critically endangered terrestrial jewel orchid. It is monotypic and endemic to evergreen forests of southern western ghats of India. In the present study, identification of this plant species is validated with DNA barcoding using K and L chloroplast markers. Further, germ-free juvenile axillary bud explants were cultured on Mitra medium supplemented with different kinds of cytokinins like 6-benzyladenine, 6-furfurylaminopurine, N-(Δ-isopentyl) adenine, thidiazuron, zeatin and meta-topolin as well as auxins such as α-naphthaleneacetic acid, indole-3-acetic acid and indole-3-butyric acid at different concentrations and combinations for successful proliferation and establishment in vitro. After 12 weeks of culture, axillary bud explants produced an average of 30.12 ± 0.71 shoots per explant, 3.87 ± 0.06 cm shoot length, 1671 ± 2.82 mg fresh mass of proliferated shoots with a proliferation frequency of 100% on Mitra medium supplemented with 6.20 µM meta-topolin and 2.25 µM thidiazuron. No root formation was observed in in vitro proliferated microshoots. However, tiny hair like projections were observed in some elongated shoots on Mitra medium pertaining to 5.37 µM NAA. The tiny hair like structure bearing plantlets were hardened and acclimatized with 100% survival rate in the polytunnel chamber. After 8-10 months of establishment , flowering was observed. Additionally, the genetic fidelity of in vitro derived plants was tested with ISSR and SCoT marker profiling. The test results revealed that the plants derived from the protocol has 99% genetic similarity to that of the donor mother plant. This study can be applied in forensic interventions of this species, describes the maintenance of germplasm in vitro and establishment of new viable population in its original habitats by restoring existing sites of this critically endangered jewel orchid.
是一种极度濒危的陆生宝石兰。它是单型的,特产于印度西高止山脉南部的常绿森林。在本研究中,使用K和L叶绿体标记通过DNA条形码对该植物物种进行了鉴定验证。此外,将无菌幼嫩腋芽外植体接种在添加了不同种类细胞分裂素(如6-苄基腺嘌呤、6-糠氨基嘌呤、N-(Δ-异戊基)腺嘌呤、噻二唑素、玉米素和间-拓扑替康)以及生长素(如α-萘乙酸、吲哚-3-乙酸和吲哚-3-丁酸)的不同浓度和组合的米特拉培养基上,以实现体外成功增殖和植株再生。培养12周后,腋芽外植体在添加6.20 μM间-拓扑替康和2.25 μM噻二唑素的米特拉培养基上,每个外植体平均产生30.12±0.71个芽,芽长3.87±0.06厘米,增殖芽的鲜重为1671±2.82毫克,增殖频率为100% 。在体外增殖的微型芽中未观察到生根现象。然而,在添加5.37 μM萘乙酸的米特拉培养基上生长出了一些伸长芽,其中观察到了微小的毛发状突起。带有这些微小毛发状结构植株被炼苗并移栽至塑料薄膜温室中驯化处理,并获得了100%的成活率。移栽后8 - 10个月时观察到开花现象.此外,通过ISSR和SCoT标记分析对体外再生植株进行了遗传稳定性测试。测试结果显示,通过该方案获得的再生植株与供体母株具有99%的遗传相似性.本研究可为该物种的法医干预提供依据,阐述该极度濒危宝石兰种质资源体外保存技术,以及通过恢复其原生境中现有场地建立新的可存活种群等内容.