园林园艺部知识库

Passiflora xishuangbannaensis (Passifloraceae) is endemic to a few sites of Mengyang nature reserve in Yunnan, Xishuangbanna and less than 40 individuals have been recorded. Nine Pas-siflora species are endemic to Yunnan with most species occurring in South America, making P. xishuangbannaensis highly significant and emblematic to the conservation work in the region. This study is designed to provide the first protocol for in vitro organogenesis and plant regen-eration for ex situ conservation and reintroduction for an Asian Passiflora species. Using in-ternodes, petioles and tendrils we optimize calli formation and root elongation using several plant growth regulators, individually or in combination. We also assess the genetic stability of regen-erated cells. The maximum callus induction and shoot bud differentiation were both achieved on half Murashige and Skoog basal medium supplemented with 4.44 mu M 6-Benzylaminopurine and 1.08 mu M 1-Naphthaleneacetic acid. The best rooting was achieved from 30 days old, regenerated shoots on half Murashige and Skoog basal medium supplemented with 1.08 mu M 1-Naphthalene-acetic acid. Micropropagated plants were subjected to inter simple sequence repeat markers analyses. Collectively, 86 bands were generated from 6 primers of which 12 bands were poly-morphic, showing genetic variation between the regenerated plantlets and the original plant. Response to plant growth regulators was more specific than most other studies using South American species, which could be explained by the morphological and physiological differences between South American and Asian Passiflora species. Because very few individuals remain, sexual reproduction is challenging, aerial shoots are annual (rhizomatous) and because genetic variability can be a consequence of repetitive in-vitro regeneration, we advise ex-situ conserva-tion techniques based on limited regeneration events such as cryopreservation.