Self fertilising orchid found

[Torsten]

http://news.yahoo.com/s/ap/20060621/ap_on_...a_lonely_orchid

Scientists find self-fertilizing orchid

Tue Jun 20, 11:23 PM ET

For one type of orchid in China, procreating is a lonely affair. Rather than depending on insects or even the wind for pollination, scientists have discovered that the orchid Holcoglossum amesianum actually fertilizes itself, according to a report in this week's Nature.

The orchid defies gravity to twist the male part of its flower into the necessary shape to fertilize the female one, a team led by LaiQuang Huang of Tsinghua University found.

The plant does so without the help of sticky fluids or other methods used by self-pollinating plants to ensure that the pollen reaches the egg, LaiQuang reported. This makes it a new method of pollination, he said.

The team studied more than 1,900 flowers of this species, which grows on tree trunks in China's Yunnan province and flowers during the dry, windless months of February to April.

The orchid produces no scent or nectar, and the researchers did not see a single instance of pollination by an insect or by wind. Instead, the pollen-bearing anther uncovers itself and rotates into a suitable position to insert into the stigma cavity, where fertilization takes place.

This sexual relationship is so exclusive that flowers do not even transfer pollen to other flowers on the same plant, researchers found.

[Torsten]

http://www.cbc.ca/story/science/national/2.../21/orchid.html

Orchid does 360-degree twist to self-pollinate

Last Updated Thu, 22 Jun 2006 08:20:21 EDT

CBC News

An orchid growing in harsh conditions defies gravity to twist its male sexual organs 360 degrees to fertilize its female organ, Chinese scientists have discovered.

The Holcoglossum amesianum orchid is shown in its natural habitat during the flowering season. (Courtesy of LaiQiang Huang, Tsinghua University Graduate School at Shenzhen) The Holcoglossum amesianum orchid is shown in its natural habitat during the flowering season. (Courtesy of LaiQiang Huang, Tsinghua University Graduate School at Shenzhen)

The pink-flowered orchid, Holcoglossum amesianum, grows on tree trunks at altitudes of 1,200 to 2,000 metres in China's Yunnan province.

The plant flowers during the drought season from February to April, when there is no wind.

Under such conditions, the plant can't use the traditional means of mating used in flowering plants, such as relying on insects or other animals, wind, or gravity to carry the pollen.

In Thursday's issue of the journal Nature, LaiQiang Huang of the centre for biotechnology and biomedicine at Tsinghua University in Shenzhen, China, and colleagues report what they say is a new type of self-pollination mechanism.

"Without pollinators for outcrossing, the necessity of ensuring reproductive success must outweigh the potential adverse effects of inbreeding," the study's authors concluded.

"The present self-contained pollination mechanism is likely to be an adaptation to the orchid’s dry and insect-scarce habitat, and may be widespread among species growing in similar environments."

Unlike other self-pollinating plants, the orchid doesn't appear to use sticky fluids or other methods to ensure the pollen reaches the egg. The flower still has signs of features for cross-pollination, but it no longer secretes nectar or odour to use them.

Instead, the pollen-bearing anther uncovers itself and rotates through 360 degrees to insert pollen into its female cavity, the stigma.

The researchers examined more than 1,900 flowers over three flowering seasons. All used the same pollination strategy.

[mr toodly]

http://news.yahoo.com/s/ap/20060621/ap_on_...a_lonely_orchid

The orchid defies gravity to twist the male part of its flower into the necessary shape to fertilize the female one, a team led by LaiQuang Huang of Tsinghua University found.

The plant does so without the help of sticky fluids..

A great improvment upon the status quo.

[-bijanto-]

Scientists find self-fertilizing orchid

I think this is not an accurate title regarding this article. It should be termed "self-pollination" instead of "self-fertilization". In this case, the species is self fertile AND the stamens and the stigma of the pistil contact each other to accomplish pollination. So it doesn't require an outside pollinator such as bees, winds etc.

"Self-fertilization" or "self-pollenization" has different meaning, In this case, the species is self fertile BUT the stamens and the stigma doesn't actually have to contact each other to carry out pollination, which means outside pollinator may be involved and may be not.

Thank's for the article, Torsten. Anyone knows why I've never gotten any seeds from my kratom plant? It seems that pollination has never been successful, is it self fertile, or: can it pollenize itself? Can a tissue-culture-grown kratom plant produce seeds, and how?

Regards,

- BJ -

Edited June 23, 2006 by -bijanto-

[Torsten]

yep, I agree.