personally, i haven't seen this in my amaryllis seedlings; they're
full siblings, and they absolutely duke it out for resources in the
pots...




Plants Know Their Relatives — And Like Them!

* By Hadley Leggett Email Author
* October 14, 2009 |
* 6:01 pm |
* Categories: Agriculture, Biology
*

arabidopsis

Unlike many human brothers and sisters, plant siblings appear to do
their best to get along, sharing resources and avoiding competition.

In a study of more than 3,000 mustard seedlings, scientists discovered
that the young plants recognize their siblings — other plants grown
from the seeds of the same momma plant — using chemical cues given off
during root growth. And it turns out mustard plants won’t compete with
their brethren the way they will with strangers: Instead of rapidly
growing roots to suck up as much water and minerals as possible,
plants who sensed nearby siblings developed a shallower root system
and more intertwined leaves.

“It’s possible that when kin are grown together, they may balance
their nutrient uptake and not be greedy,” plant biologist Harsh Bais
of the University of Delaware said in a press release. The work will
be published in an upcoming issue of Communicative and Integrative
Biology.

Two years ago, co-author Susan Dudley of McMaster University in Canada
observed a similar pattern in the sea rocket, a common seashore plant
that also appears to favor its siblings. But the initial studies of
kin recognition have been criticized for failing to control for
complicating factors, such as resource depletion caused by competition
between the unrelated plants. And until now, the researchers didn’t
know how plants managed to identify their kin.

As seedlings grow, their developing root system gives off a variety of
chemical signals, and the researchers guessed that these secretions
might play a role in sibling recognition. To test their theory, the
scientists grew wild Arabidopsis thaliana in a sterile liquid
containing root extracts from sibling plants, unrelated plants or
their own roots. Because each plant was grown in a highly controlled
setup, the researchers could be sure any changes in growth were due to
differences in the root extracts.

As shown in the time-lapse videos below, the seedlings exposed to root
secretions from unrelated plants grew significantly longer and more
elaborate root systems than those grown in secretions from their
siblings. The top video shows unrelated plants, while the bottom one
shows siblings.

However, when the scientists blocked root secretions using a chemical
called sodium orthovanadate, the differences disappeared, suggesting
that the sibling identification system indeed depends on chemicals
released by growing roots.

The researchers say their results may have significant implications
for farming and agriculture. Although no one knows for sure how
sibling recognition would affect crops grown in large monocultures,
some researchers think that decreased competition among plants from
identical seeds may make monocultures more susceptible to insects and
disease.

However, Bais says that the effect of growing a plant with its
siblings is likely to be species-dependent, as initial studies have
been contradictory. “There is a possibility that the explanation of
the trade-offs is not that simple,” he wrote in an e-mail. “We have
found that plants could resist pathogens better when grown with
siblings compared to strangers, so I would take this with caution and
not stretch it to all the plant species.”

Regardless of how sibling recognition affects agriculture, it may be
an important consideration for the home gardener.

“Often we’ll put plants in the ground next to each other and when they
don’t do well, we blame the local garden center where we bought them
or we attribute their failure to a pathogen,” Bais said in the press
release. “But maybe there’s more to it than that.”

http://www.wired.com/wiredscience/20...lant-siblings/

--j_a

This would explain why orchid seedlings need compots.

Diana

"jankey" wrote in message
...
personally, i haven't seen this in my amaryllis seedlings; they're
full siblings, and they absolutely duke it out for resources in the
pots...




Plants Know Their Relatives — And Like Them!

* By Hadley Leggett Email Author
* October 14, 2009 |
* 6:01 pm |
* Categories: Agriculture, Biology
*

arabidopsis

Unlike many human brothers and sisters, plant siblings appear to do
their best to get along, sharing resources and avoiding competition.

In a study of more than 3,000 mustard seedlings, scientists discovered
that the young plants recognize their siblings — other plants grown
from the seeds of the same momma plant — using chemical cues given off
during root growth. And it turns out mustard plants won’t compete with
their brethren the way they will with strangers: Instead of rapidly
growing roots to suck up as much water and minerals as possible,
plants who sensed nearby siblings developed a shallower root system
and more intertwined leaves.

“It’s possible that when kin are grown together, they may balance
their nutrient uptake and not be greedy,” plant biologist Harsh Bais
of the University of Delaware said in a press release. The work will
be published in an upcoming issue of Communicative and Integrative
Biology.

Two years ago, co-author Susan Dudley of McMaster University in Canada
observed a similar pattern in the sea rocket, a common seashore plant
that also appears to favor its siblings. But the initial studies of
kin recognition have been criticized for failing to control for
complicating factors, such as resource depletion caused by competition
between the unrelated plants. And until now, the researchers didn’t
know how plants managed to identify their kin.

As seedlings grow, their developing root system gives off a variety of
chemical signals, and the researchers guessed that these secretions
might play a role in sibling recognition. To test their theory, the
scientists grew wild Arabidopsis thaliana in a sterile liquid
containing root extracts from sibling plants, unrelated plants or
their own roots. Because each plant was grown in a highly controlled
setup, the researchers could be sure any changes in growth were due to
differences in the root extracts.

As shown in the time-lapse videos below, the seedlings exposed to root
secretions from unrelated plants grew significantly longer and more
elaborate root systems than those grown in secretions from their
siblings. The top video shows unrelated plants, while the bottom one
shows siblings.

However, when the scientists blocked root secretions using a chemical
called sodium orthovanadate, the differences disappeared, suggesting
that the sibling identification system indeed depends on chemicals
released by growing roots.

The researchers say their results may have significant implications
for farming and agriculture. Although no one knows for sure how
sibling recognition would affect crops grown in large monocultures,
some researchers think that decreased competition among plants from
identical seeds may make monocultures more susceptible to insects and
disease.

However, Bais says that the effect of growing a plant with its
siblings is likely to be species-dependent, as initial studies have
been contradictory. “There is a possibility that the explanation of
the trade-offs is not that simple,” he wrote in an e-mail. “We have
found that plants could resist pathogens better when grown with
siblings compared to strangers, so I would take this with caution and
not stretch it to all the plant species.”

Regardless of how sibling recognition affects agriculture, it may be
an important consideration for the home gardener.

“Often we’ll put plants in the ground next to each other and when they
don’t do well, we blame the local garden center where we bought them
or we attribute their failure to a pathogen,” Bais said in the press
release. “But maybe there’s more to it than that.”

http://www.wired.com/wiredscience/20...lant-siblings/

--j_a