Single peat moss plant 'conquered America' | ||||||||
  The plant that conquered: the peat moss Sphagnum subnitens It is the most extreme example yet known of a single plant's ability to colonise sites spanning a huge region. Across northwestern North America, every example of a common peat moss called Sphagnum subnitens is genetically identical, researchers have discovered. That means every specimen can be traced back to a single parent, which likely conquered North America in less than 300 years, and shows how a single 'general purpose' genome can allow a plant to grow in a range of climates. As part of the same research, scientists also discovered that just two parent peat moss plants of the same species have also produced all those now living in New Zealand.
Both results are "extremely surprising", say the plant ecologists who did the research. One reason is because the same is not true in Europe, where a wide variety of S. subnitens mosses live. Details of the discovery are published in the journal Molecular Ecology. Professor Eric Karlin of Ramapo College in New Jersey, US and colleagues at Binghamton University in New York state, US and Duke University, in Durham, North Carolina, US were initially studying the global distribution of S. subnitens. "Like other peat mosses, the plant grows in bogs and fens," Prof Karlin told BBC News. Standing just a few centimetres tall, the plant forms carpets and can vary in colour from green to red to brown. "It is not uncommon," says Prof Karlin, but it does have an odd distribution, occurring widely in Europe and across coastal northwestern North America, and again in New Zealand, where it is limited to the west coast of the South Island. "Prior to this study there had been no analysis to assess the genetic relationships of the plants in these remarkably disjunct populations," he adds.
So he and colleagues did just that, also measuring the amount of genetic variety within populations of the peat moss growing on each continent. "All of the plants of S. subnitens in northwestern North America appear to have descended from just one parent," says Prof Karlin. "100% of the gene pool was contributed by one individual." Genetically identical plants of S. subnitens range from coastal Oregon to the western Aleutian Islands, a distance of some 4115km. In New Zealand, the populations there were founded by two different parents. But interestingly, these do not appear to have interbred. "Thus all plants of S. subnitens in New Zealand are genetic copies of either one or the other founding parent." The peat moss appears able to colonise many sites across extensive geographic regions due to its complicated way of reproducing. Mosses can reproduce in a number of ways. Either a moss plant clones itself, by passing on exactly the same DNA to new individuals via vegetative reproduction.
Or it can reproduce by sexual reproduction. In humans and most animals, this usually occurs with a male parent providing the sperm and the female parent the egg, each supplying half their offspring's genetic material. Peat mosses can do this, but they can also sexually reproduce another way, with the same parent producing both the sperm and egg. This sperm and egg are also genetically different to each other, due to the way genetic material gets shifted around when they are created. S. subnitens also has a fourth way of reproducing, however. One parent can produce egg and sperm that are genetically identical. When these sperm and eggs come together, they produce offspring containing two copies of identical DNA. That means the offspring are genetically the same as their parent, without technically being clones. This special type of sexual reproduction only occurs in some mosses and some other seedless plants such as ferns. That is what Prof Karlin's team believes has happened in North America and New Zealand.
A single founder plant arrived in North America from Europe, probably sometime between the turn of the 18th and 20th Centuries. It then reproduced, spreading genetically identical copies of itself along the northwestern coast. "It can be argued that this is the most genetically uniform widespread group of plants known," says Prof Karlin. Two different plants of this species must have arrived in New Zealand, and individually spread in the same way. In neither North America, nor New Zealand, do any of the plants of S. subnitens show signs of genetic variation from the founding parents. The apparent health of the peat moss populations indicates that the plant has not suffered from having no diversity in its genetic make up. Prof Karlin explains: "This is in sharp contrast to many animals and plants." For them, inbreeding often leads to a concentration of unwanted genetic mutations, compromising their evolutionary fitness, he says. But this peat moss shows how many ecological niches can be filled by just a single genome, albeit one copied many times. "It appears that the species has a 'general purpose' genotype that can thrive without specialisation to each location where it occurs," says Prof Karlin. | ||||||||
Saturday, February 12, 2011
The plant that conquered
It can be argued that this is the most genetically uniform widespread group of plants known 
Monday, February 7, 2011
THE KING of the kings of fruits!
The first four boxes of this rare and delicate variety of the king of fruits were sold for Rs 7,000 each in Mumbai’s popular fruit and vegetable bazaar, the Crawford Market, in January.
That is Rs. 583 per mango! The predicted rates for March are Rs. 2000-3000 per dozen (Rs. 200 per piece)!
Any orders????
7 Feb, 2011, 11.44AM IST, Jayashree Bhosale & Ram Sahgal,ET Bureau
12 Alphonso mangoes sell for Rs 7,000 in 'Mahurat' trading
PUNE | MUMBAI: You can call it mango ‘mahurat’ trading. This year’s first Alphonso mango has fetched a record Rs 600, almost 50% more than the last year’s opening price.
The first four boxes of this rare and delicate variety of the king of fruits were sold for Rs 7,000 each in Mumbai’s popular fruit and vegetable bazaar, the Crawford Market, in January. Each box contained a dozen Alphonsos.
In Pune, the first box of 40 Alphonsos was sold at an auction conducted by the Agricultural Produce Market Committee (APMC) for Rs 11,111. This would translate into a retail price of Rs 450 per mango. The winning bidder was Ravsaheb Kunjir, an NRI. “Parents planning to visit their children in other countries usually take a few pieces of mangoes with them, even if they are expensive,” Kunjir told ET. These prized first few boxes come two to three months ahead of the main season, which usually starts in April. The fruit grows from early flowering in the rainy season.
“The high mahurat price is paid in order to get publicity,” said Nathsaheb Khaire, owner of PL Khaire and Sons, a grapes and mangoes trader in Pune. “The trader himself may not make much profit from the transaction. He may even have to sell those mangoes for a loss.”
Low supply has given a boost to the opening price this year. “Last year, we sold the first mangoes at Rs 4,500 a dozen. But this year, we have not got any early fruit from our orchards,” said Amar Desai, chief executive of the Pune-based Desai Bandhu Ambewale. Desai’s family owns orchards in Pawas in Ratnagiri district of Maharashtra and has been trading mangoes for the past 75 years. The exorbitant price proves that the first boxes are more about lifestyle than taste. “The first mangoes usually go to politicians, film stars and the rich families in Mumbai,” said Prakash Bang, a marketing professional who packs and door delivers mangoes under the brand name Bangoes.
Yogesh Dhole, a fruits wholesaler and retailer in Crawford market, agreed. “Initial tranche of mangoes are purchased by large corporate houses, diamond merchants and film personalities,” he said. But it is only a matter of time before Alphonsos become affordable for the middle classes. The crop is expected to be good, though the season may be delayed by up to two months due to unseasonal rainfall, experts said. “As there was less than average mango production for two consecutive years, trees have abundant food storage, which will result in high fruit bearing this year,” said a scientist at the Balasaheb Savant Konkan Krishi Vidyapeeth, the state-run agricultural university in Konkan, Maharashtra.
“Alphonso arrivals will begin in March but the price will be Rs 2,000-3,000 per dozen,” Desai said. “The arrivals will be in full swing only in April, when the fruit becomes affordable for all.” Wholesale fruit markets are also waiting for the king. “While last year there was crop damage due to a heat wave in the first week of April, this year we expect the crop output to be much better in the period after mid-April because of better weather conditions currently,” said Sanjay Narayan Pansare, director of APMC in Navi Mumbai.
Saturday, February 5, 2011
Three Storms on Earth (as seen from space)
For earthlings, a storm on our planet can be awesome or awful depending on its severity. This satellite image shows three storms in the Atlantic Ocean on Aug. 30. 2010: Hurricane Danielle (top, center) is heading for the north Atlantic, while Hurricane Earl (bottom, left) has a visible eye hitting the Leeward Islands. Meanwhile, developing tropical depression 8 is churning in the lower-right hand portion of the image.
A Perfect Storm
In April 2001, a temperate cyclone spun counter-clockwise over China, pushing a wall of dust as it moved. Not only was the tan dust thick enough to completely hide much of the land surface below, but is also almost formed its own topography, with ridges of dust rising up below the clouds.
An eye-witness to the dust storm who visited Jilin Province in northeastern China reported that around 7 a.m. local time on April 7, 2001, the dust blocked enough sunlight to leave the skies as dark as midnight. Researchers watched with surprise as dust from an Asian storm crossed the Pacific, reaching as far east as the U.S.s Great Lakes.
South Pole Aurora Australis
Auroras, such as the aurora australis seen here, are the result of solar flares and coronal mass eruptions on the sun. Though beautiful, the auroras' accompanying magnetic energy impulses often cause disruptions in electronic and communications technology.
Understanding Auroras
In 2007, NASA launched THEMIS (Time History of Events and Macroscale Interactions during Substorms), a 2-year mission to improve the understanding of how severe space weather effects on Earth.
The mission consisted of five identical probes that orbit the earth and line up over the United States every four days. In this artist's rendering, THEMIS' main orbits are represented by red ovals. Blue lines represent the Earth's magnetic field. The white flash represents energy released during substorms.
Mars Swirls
Martian winds blowing through the planet's sand dunes make intricate patterns -- a phenomena captured by the Mars Reconnaissance Orbiter.
Clouds of Neptune
Does Neptune have clouds? This Voyager 2 image provides obvious evidence of vertical relief in Neptune's bright cloud streaks. These clouds were observed at a latitude of 29 degrees north near Neptune's east terminator, the "line" on a planet where daylight meets darkness.
Jupiter Swirls
This close-up of swirling clouds around Jupiter's Great Red Spot was assembled from three black-and-white negatives taken by Voyager 1 on March 5, 1979. At 617 kilometers (384 miles) per hour, the winds around Jupiter's Red Spot are nearly two times as strong as the winds that accompany Category Five hurricanes on Earth.
Jupiter's Volcanic Moon, Lo
Jupiter's moon Lo (shown in a composite photograph with Jupiter in the background) is the most volcanically active object in our solar system. This image shows a major eruption in progress on Io's night side. Incandescent lava glows red beneath a high volcanic plume, whose uppermost portions are illuminated by sunlight. The plume appears blue due to scattering of light by small particles in the plume
Dragon Storm on Saturn
The complex feature with "arms" and "secondary extensions" just above and to the right of the center in this image is called the Dragon Storm. It lies in a region of Saturn's southern hemisphere that scientists call "storm alley" because of the high level of storm activity observed there by the Cassini-Huygens mission.
Icy Frigid Triton
A color mosaic shows Neptune's moon Triton. By far the largest satellite of Neptune, Triton is so cold that most of its nitrogen is condensed as frost, making it the only satellite in the Solar System known to have a surface made mainly of nitrogen ice. The bluish-green band visible in this image extends all the way around Triton near the equator; it may consist of relatively fresh nitrogen frost deposits.