Histological and micro-CT evidence of stigmatic rostellum receptivity promoting auto-pollination in the madagascan orchid Bulbophyllum bicoloratum.

ABSTRACT:

Background

The rostellum, a projecting part of the gynostemium in orchid flowers, separates the anther(s) from the stigma and thus commonly prevents auto-pollination. Nonetheless, as a modified (usually distal) portion of the median stigma lobe, the rostellum has been frequently invoked of having re-gained a stigmatic function in rare cases of orchid auto-pollination. Here it is shown that a newly discovered selfing variant of Madagascan Bulbophyllumbicoloratum has evolved a modified rostellum allowing the penetration of pollen tubes from in situ pollinia.

Methods

Gynostemium micro-morphology and anatomy of selfing and outcrossing variants of B. bicoloratum was studied by using light and scanning electron microscopy and histological sections. Pollen tube growth in the selfin

SUBMITTER: Gamisch A 

PROVIDER: S-EPMC3742538 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature