Strategies for the recovery of endangered orchids and cacti through in-vitro culture

Published source details Rubluo A., Chávez V., Martínez A.P. & Martínez-Vázquez O. (1993) Strategies for the recovery of endangered orchids and cacti through in-vitro culture. Biological Conservation, 63, 163-169.
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Summary

Orchids (Orchidaceae) and cacti (Cactaceae) comprise many endangered species, primarily due to over-collection and habitat loss. Efficient propagation may help to bolster wild populations. This study attempted mass in-vitro culture of eight orchid and three Mexican cactus species. Restoration into the wild was undertaken for some,focusing on bolstering the population of the near-extinct cactus Mammillaria san-angelensis (five individuals in the wild) in its natural habitat near Mexico City.

Eight orchid (Bletia urbana, Lycaste skinneri, L.aromatica, Lemboglossum ehrenbergii, Oncidium stramineum, Laelia anceps, Encyclia citrina and Rhyncholaelia glauca) and three cactus (Mammillaria haageana, M.huitzilopochtli and M.san-angelensis) species were selected for in-vitro culture.

Micropropagation techniques for M.san-angelensis (due to its rarity), were developed using M.haageana (a relatively abundant and closely related species).

After propagation and acclimatization (see original paper for details) young propagated plants of four of the orchid species and M.sans-angelensis were out-planted into their natural habitats. Observations were made every 4-6 months to determine survival rates and growth. Height of M.sans-angelensis plants was recorded every 15 days until day 75, thereafter 1 and 2.5 years later.

Orchids: Good responses to in-vitro culture were achieved, all species successfully producing seedlings. However, only single seedlings of E.citrina, L.anceps and R.glauca were grown on successfully. Of the others, B.urbana (2,000 seedlings); L.ehrenbergii (500); L.aromatica (2,800) and L.skinneri (6,300) were still alive in the greenhouse after one year.

Of the four out-planted species, numbers of individuals introduced into the wild and survival were: B.urbana (133; 15% after 4 years); L.aromatica (1,200; 60% after 1 year); L.skinneri (2,400; 70% after 1 year); and O.stramineum (700; 40% after 2 years). During the dry season they survived as either corms or plants with leaves. In the following rainy season, new leaves were produced and lateral shoots formed.

Cacti: M.san-angelensis was successfully cultured from stem sections (2,000 plants; 100% survival in the greenhouse). Of these, 47 individuals were out-planted at the wild site in May 1986 (beginning of the rainy season). After 900 days, 43 (91%) were still present and alive (four were removed by people). The plants had grown in length, from an average of 16.9 mm (range: 15.4-17.8) to 26.3 mm (19.1-35.0). In November 1988, 2.5 years after planting out, four individuals derived in vitro flowered and produced fertile seeds.

M.huitzilopochtli seedlings were produced in the in-vitro-culture medium but efforts to root them failed.

Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at: http://www.sciencedirect.com