Germination and growth ofErythrorchis ochobinesis (Orchidaceae) accelerated by monokaryons and dikaryons ofLenzites betulinus andTrametes hirsuta

Four sib-monokaryons and two reconstituted dikaryons of two basidiomycetes,Lenzites betulinus andTrametes hiruta, accelerated the seed germination ofErythrorchis ochobiensis, an achlorophyllous orchid. All isolates ofL. betulinus and three isolates ofT. hirsuta induced the development of plants from germinated seeds. Although three monokaryotic isolates ofT. hirsuta failed to induce the development of plants, the reconstituted dikaryons induced the development.     

A Semivolatile Floral Scent Marks the Shift to a Novel Pollination System in Bromeliads

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Influence of growth regulators on direct embryo formation from leaf explants of Phalaenopsis orchids

Leaf explants of two Phalaenopsis, P. amabilis and P. Nebula, were used to test the effects of auxins (2,4-D, IAA, IBA, NAA), cytokinins (2iP, BA, kinetin, TDZ, zeatin), GA₃, ancymidol, polyamines (putrescine, spermine, spermidine), ACC, AgNO₃ and CoCl₂ on the amount of direct embryo formation on different leaf locations (the cut end, the adaxial side, the abaxial side and the leaf tip). The results showed that there was a genotypic effect on direct embryo formation induced by cytokinins that 13.32 μM BA and 4.92 μM 2iP was the most effective in P. amabilis and P. Nebula, respectively. Besides, explant position highly affected embryogenic competence of leaf cells in both species that the cut end showed highest embryogenic response, the adaxial side was the second, and then the abaxial side and the leaf tip. Altogether, cytokinins tested were all effective in both species, and ACC at 20 μM had 35% of embryogenic response in P. amabilis. However, auxins, GA₃, ancymidol and polyamines were inhibitory in both species.