In vitro cloning via direct somatic embryogenesis and genetic stability assessment of Paphiopedilum niveum (Rchb.f.) Stein: the endangered Venus’s slipper orchid

• Published in: In vitro cellular & developmental biology. Plant Vol. 55; no. 3; pp. 265 - 276
• Main Authors: Soonthornkalump, Sutthinut, Nakkanong, Korakot, Meesawat, Upatham
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2019
• Subjects: activated carbon; bananas; Biomedical and Life Sciences; Cell Biology; climate change; Developmental Biology; extinction; genetic similarity; genetic stability; greenhouse production; histology; in vitro studies; Life Sciences; Micropropagation; naphthaleneacetic acid; Paphiopedilum niveum; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Plant Sciences; plantlets; random amplified polymorphic DNA technique; somatic embryogenesis; somatic embryos; (Rchb.f.) Stein; Histology; Direct somatic embryogenesis; RAPD; Protocorm-like bodies; Micropropagation of
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/s11627-019-09981-7

Wild populations of Paphiopedilum niveum (Rchb.f.) Stein, an endangered orchid species, have been threatened with extinction due to climate change and overcollection. Conventional methods of propagation are unable to meet market demands. The current study reports the production of genetically stable, protocorm-derived protocorm-like bodies (PLBs) of P. niveum that can be used for commercial production. These PLBs are referred to hereafter as somatic embryos (SEs). Factors affecting SE induction and SE proliferation were examined. The highest percentage of SE formation (68.33 ± 11.77%) and the maximum number of SEs per explant (5.19 ± 0.67) were obtained on modified Vacin and Went (MVW) medium containing 0.1 mg L −1 1-naphthaleneacetic acid (NAA). The highest increase in fresh weight (FW) of proliferated SEs (183.33 ± 28.93 mg per 100 mg initial FW) was gained on hormone-free MVW. These SEs eventually developed into vigorous plantlets after culturing on MVW supplemented with 0.2% ( w / v ) activated charcoal and 50 g L −1 banana homogenate for 12 wk. A histological study revealed that SEs originated from both the epidermal and the sub-epidermal layers of the original protocorm via direct somatic embryogenesis. The genetic homogeneity between the mother generation (V 1 ; the original protocorm) and subsequent generations (V 2 and V 3 ; the primary and secondary somatic embryos, respectively) was shown to be identical via random amplification of polymorphic DNA (RAPD) assessment. All regenerated plants grew well under greenhouse conditions.