Heirloom varieties and volatile organic compounds
a follow on from the last article about NGT's
So here we go, I wrote recently about the pressure being brought on governments to adopt New Genomic Technique crops, ones that have had their genome manipulated, in this case to produce ‘climate ready’ crops.
Plants interact and respond to their enviroment, they change it and it changes them, the most adapted thrive and reproduce. A plant isn’t alone but accompanied by insects, animals, fungi, bacteria and on. Plants communicate and one way they do this is to produce volatile organic compounds (VOC) these are messages to anyone capable of understanding them. As a plant is eaten by an insect it produces VOC’s and these can be picked up by the predators of the attacking insect. They can also be picked up by other individuals of the same attacking species signalling that there is a food source nearby. The VOC’s can be picked up by the same type of plants in the area pre-warning them and giving thel time to prepare their defenses. The VOC’s attract beneficial soil organisms such as arbuscular mycorrhizal fungi which help a plant capture essential nutrients from the soil.
We have been selecting and cross-breeding plants for millennia, we have selected for certain traits such as resiliance, flavour, disease resistance and so on. A new variety would have to prove itself, stand the test of time so to speak and with each harvest the best specimens from the crop would be kept for seeds. A great thing with tomatoes and other similaer crops is that we get to eat eat the fruit and keep the seeds of the ones we like the most, this happened with each harvest. When we started to develop synthetic agricultural chemicals and atificial nitrogen we also started crossing crops to create varieties adapted to high levels of nitrogen, to greenhouses and in particular to the global food system. Faster growing, faster maturing and capable of absorbing the high levels of nitrogen and all the other things we feed them.
Years ago a gene mutation in toamtoes was discovered which meant that a tomato was red all over, uniformly, an interesting trait for tomato producers and one which was bred into virtually all the major commercial tomato varieties grown today. Unfortunately the gene mutation reduces the quantity of sugar and carotenoids in the fruit itself. The latter are strong antioxidants and a source of provitamin A, we ended up with tomatoes that have little flavour and are less nutritious. Things whch would have been selected away from by our ancestors.
Back to the VOC’s, studies have shwon that modern varieties produce lower levels of these volatile molecules when compared to heirloom varieties. It was also found that the arbuscular mycorrhizal fungi whilst helping the tomatoes get nutrients and have better growth also encourage the plant to produce more VOC’s helping it protect itself and warn neighbouring plants. The cultivated varieties are less attractive to the arbuscular mycorrhizal fungi and therefore don’t benefit as much.
When we speed things up, in this case crossing plants and now using New Genomic Techniques, we short circuit the process of natural or artificial selection, the latter being what I mentioned above and what we have been doing since the dawn of agriculture. Today we trap ourselves in a loop of knee jerk reaction such as rush manipulating plats to be ‘climate friendly’. We don’t take sufficient time to explore the mechanisms that are already there and which we often destroy with our new varieties.
I’m not saying that we should stop cross-breeding plants to discover new varieties that are more drought resistant. What I am saying is that we must do this in a way that takes into consideration all of the interactions that a plant may have with it’s environment. It may be that we could create a NGT more drought resistant form of wheat or maize but these crops would be grown in today’s standard of plough agriculture. Arbuscular mycorrhizal fungi networks increase crop yields, ploughing destoys these networks. We have to think more in terms of systems and less in terms of individuals, and profit. We can improve yields by encouraging arbuscular mycorrhizal fungi which will involve moving away from plough agriculture and we can further enhance this by moving towards agroforestry systems as discussed in the previous article. In these systems the positive relationships between plants are boosted and so is yield quality.
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"I’m not saying that we should stop cross-breeding plants to discover new varieties that are more drought resistant. What I am saying is that we must do this in a way that takes into consideration all of the interactions that a plant may have with it’s environment." Yes, and surely, that such breeding is open source and not able to be patented to restrict ownership with an aim of financial profit as well as fostering dependency!