Have you noticed in your garden that there are relationships between different life forms where one form of life is dependent on another life form for its survival. The easiest symbiotic relationship to see is a flower and a bee. The flower produces pollen, which is one half of its survival mechanism. In order to reproduce, the flower needs this pollen to be distributed.
Pollination definition from Wikipedia.
Pollination is the process by which pollen is transferred from the anther (male part) to the stigma (female part) of the plant, thereby enabling fertilization and reproduction. It is is unique to the angiosperms, the flower-bearing plants.
Enter the bee
The bee is attracted to the pollen produced by the flower and happily skips from flower to flower collecting pollen, it also fertilises the flower so that it can create seeds and ensure its future survival. Without the bee the flower would be relying on other less productive insects for its pollination.
The ginger family and earthworms
If you have ever harvested ginger, galangal, turmeric, kraichi or any other ginger like rhizomes you will dig up a lot of worms that have made home in the rhizomes. They are not your small red wriggler compost worms but the large fat deep diving ones that are usually found deeper in the garden. Yet here they are only a few centimetres deep in the rhizomes.
Maybe, like in Dune (a science fiction classic) the ginger family has a thumper that creates a pulse or rhythmic beat that attracts these worms to the rhizome. Or, more likely, the rhizome exudes a substance that is intoxicating to the worm and attracts them. In return the plant benefits from the worm castings.
I harvested some turmeric yesterday but didn’t take a snap of the worms. But I watched a RobBob video of him harvesting some garlic and turmeric and the worms he found in the rhizomes. Click on the video and it will open in a new window
Soybeans and Rhizobia bacteria
An invasion of soybean aphids poses a problem for soybean farmers requiring application of pesticides, but a team of Penn State entomologists thinks a careful choice of nitrogen-fixing bacteria may provide protection against the sucking insects.
Soybeans are legumes, plants that can have a symbiotic relationship with nitrogen-fixing bacteria — rhizobia — and therefore do not need additional nitrogen fertilizer. Each type of legume — peas, beans, lentils, alfalfa — have their own rhizobia.
“Soybeans are from Asia and so there were originally no nitrogen-fixing bacteria that would colonize soybeans in U.S. soils,” said Consuelo De Moraes, associate professor of entomology. “The rhizobia had to be transferred here.”
The soybean aphid is also not native to North America. This pest only began to infest soybean fields about 10 years ago but are now fully established pests requiring pesticide applications to avoid the loss of as much as 40 percent of the crop. The researchers investigated the relationship between the type of rhizobia colonizing soybean plants and the plants’ infestation with the aphids.
“Our results demonstrate that plant–rhizobia interactions influence plant resistance to insect herbivores and that some rhizobia strains confer greater resistance to their mutualist partners than do others,” the researchers report in the journal Plant and Soil online.
The above information is from Science Daily. The complete article goes on to describe how wild native rhizobia bacteria help overcome the problem of the soybean aphid, but the bacteria used as an innoculant is an aggressive bacteria that fights off the wild native bacteria. They describe the experiments undertaken to prove their theory.
Fortunately, here in Brisbane I haven’t had the problem of aphids in the soybeans I grow, needless to say, one day it will come. At the moment I grown soybeans all year round. That way I am trying to create a wild bacteria that is in the ground and becoming indigenous. I harvest some seed early and let it fall into the garden. By the time I harvest the rest, young soybean plants are growing and providing a home for the rhizobia bacteria in the nodules they create in the root system.
This picture was taken this morning. It is late winter here in Brisbane and although these are not growing as well as in summer, they are providing a home for the rhizobia. This is the first time I have done this and it will be interesting to see the result and if they produce any beans. There are a couple of other soybean posts that should be listed in the tags below.
All the above examples are symbiotic relationships where both parties get benefits from their relationship. The bee gets pollen and the flower is pollinated. The worm, I am sure gets something and the ginger gets the benefit of tunnels for oxygen and the goodness from the worm castings. The soybean gets the nitrogen from the rhizobia in a form that it can uptake and the bacteria gets a root exudate that it can feed on.
From working in the garden and seeing all these things going on, I sometimes wonder why I have a pathological dislike for cabbage moths and cane toads. I am sure that there is something that benefits from their existence, but as yet I am still unable to fathom it.
What about ourselves? How do we benefit this earth that we live on? If you watch the television or read a newspaper there is not much evidence that we are a benefit. It would appear that man and woman are more a detriment than a benefit.
Fortunately there are quite a few people out there who are trying in their own way to lessen their detrimental footprint and improve their beneficial one. People like RobBob and many others whose blogs I have read or YouTube channels I have watched.
I read one blog where the young lady from Melbourne has gone plastic free. I haven’t got that enthusiastic yet, but every time I find plastic in my compost, I think of her and send up a silent thank you for people like her.