Self-pollination of the orchid Cycnoches haagii from Brazilian Cerrado results in albino phenotype seedlings

Abstract

Cycnoches haagii Barb. Rodr. is an epiphytic orchid very targeted by collectors, but no reference was found in the literature about its reproductive biology. Thus, the purpose of this study was to obtain initial information regarding pollination types and its influenceon seed viability of this native orchid of the Brazilian Cerrado, in order to enable future propagation and preservation programs.Pollination among flowers of the same plant (geitonogamy) or different plants (xenogamy) were carried out. Seeds extractedfrom the capsules were sown in B&G medium, with full and half strength. Seeds from geitonogamic resulted in 25% of albinoprotocorms and consequently in albino seedlings. This phenomenon did not occur in seedlings derived from xenogamic pollination.Pigment analysis showed that even the albino seedlings presented chlorophylls and carotenoids, however, in significantly minorconcentrations, 16% and 37% respectively, in relation to green seedlings. Geitonogamic and xenogamic pollinations resulted in C.haagii viable seeds with high germination percentage (90%) under in vitro conditions. The germination of seeds from xenogamicpollination resulted in chlorophyll or normal seedlings only, and can be recommended at conservation programs. On the other hand,although geitonogamic pollination should be avoided at conservation programs of this orchid species as it leads to albino seedlings,it showed a very interesting system to obtain seedlings with this phenotype, an interesting plant material to future investigation.Keywords: albinism, geitonogamy, germination, orchid, plant pigments