Reproductive biology of Angraecum eburneum subsp. superbum (Orchidaceae) under glasshouse conditions

摘要

The results of long-term observations on the reproductive biology of an epiphytic monopodial orchid, Angraecum eburneum subsp. superbum, under glasshouse conditions are provided. Experimental pollination treatments (induced autogamy/induced xenogamy) indicated that A. eburneum subsp. superbum is a self-compatible but not an autogamous orchid. The fruit set after self- and cross- pollination significantly differed. Cross-pollination had positive effect on seed viability of A. eburneum subsp. superbum under glasshouse conditions. The fruit set, seed mass and seed viability were compared with respect to flower position within an inflorescence. The position of pollinated flowers within the inflorescence was found to affect the fruit and seed mass, but not seed viability. The impact of various factors, including breeding systems, pollination strategies, flowering longevity, pollinated flower position in inflorescence and resource status, upon reproductive success of the orchid studied ex situ was analyzed.