First up, if you're one of the many, many people to whom I owe emails or packages of seed or whatever else, please accept my apologies for being slow at the moment. I'm swamped, and it's going to take me a little while to clear my inbox. I'm trying to keep the blog going in the mean time though.
Last autumn I bought a manouille (bunch) of Rose de Lautrec garlic at a French market in Brighton, while I was down there visiting my music collaborator. There was plenty of it, so I had lots to eat and to plant.
Rose de Lautrec has its own official website complete with obligatory romantic story about its medieval origins. It's a hardneck type and reputed to be very longkeeping. It's also reputed to have a "sweet and subtle" flavour, but I'm not entirely sure about that. The bulbs I bought are searingly hot when eaten raw but the heat (and a lot of the flavour) disappears with cooking. I guess what's left is sweet and subtle, but it depends how you define it. To be honest I don't think the flavour matches up to my home-grown Music garlic, but maybe it's just my coarse English taste buds.
Actually Rose de Lautrec is not a variety, it's a Protected Geographical Indication. When it's grown outside the Lautrec region, it's not Rose de Lautrec any more. There are actually five different varieties permitted to be sold as Rose de Lautrec: the traditional Lautrec Pink and four commercial versions, Ibérose, Goulurose, Edenrose and Jardirose, and I don't know which of them I have. But for all the controlled regions stuff, these pink garlic bulbs have the same genes in my garden that they have in Lautrec, so I will probably still get something worthwhile even if they aren't the same as the "original".
Meanwhile, the F2 peas are coming along a treat. I wrote yesterday morning that 30 seeds had already germinated. I counted them again the same day just before bedtime and there were 53. Then when I got up this morning it was 63. Only one left to go! They are amazingly vigorous considering F2 seeds are supposed to lack hybrid vigour. And already it's clear that they're all different. Even as tiny seedlings, some are whiter than others, thinner than others, shaped differently, or have red flushes on the stems in varying amounts.
Wednesday, 27 February 2008
Posted by Rebsie Fairholm at 11:52 pm
Tuesday, 26 February 2008
A few days ago I sowed the first batch of F2 seeds for my yellow sugarsnap pea experiment.
I love the variability of F2 pea seeds. Most plants produce seed which looks pretty much the same regardless, so you don't get any clues as to what you're going to get from a breeding project until you actually grow the plants. Peas are unusual in that the seeds do have tantalising variations and elusive hints of what they might develop into. But you don't get to see it until the F2 stage.
When you cross two pea varieties, the resulting F1 hybrid seed looks just the same as any normal seed of the mother variety. That's because the seed is a product of the mother plant. The father's DNA is in the seed embryo, but not in the outer structure of the seed. Only occasionally will an attribute from the father be visible in the seed itself. But when the F1s are grown and self-pollinated they produce F2 seed which is very diverse in appearance. A large green crinkled pea may easily be sitting side by side with a small round tan-coloured one, right there in the same pod. The phrase "as like as two peas in a pod" is thrown out the window.
Segregating the F2 seeds into different groups
My F2 seeds show a mixture of characteristics from both breeding lines. They have some of the grey and tan colours of Golden Sweet, and varying degrees of purple speckling. Sometimes the speckles are clear and dense, other times they're blurred like purple ink on wet blotting paper. Some have the green colouring of Sugar Ann (with or without speckles) and its surface wrinkliness, while others are smooth and dimpled.
I had a slight dilemma about whether or not to segregate the seeds and plant them in groups of different types. I thought it would be interesting to see if there was any obvious correlation between the outer appearance of the seed and the type of plant that results. Some traits are known to show up in pea seeds. Wrinkled peas are an indication of higher levels of sweetness, because sugar within the seed shrinks more than starch does. It's not a hard and fast rule though, because peas often go more wrinkly if they were dried rapidly after harvest. The presence of purple speckles may indicate that a seed contains the gene for anthocyanin production (the substance which makes purple colours) which is present in Golden Sweet but probably not in Sugar Ann. I think it less likely that the actual seed colour will have a correlation with any obvious trait, but it might do. However, I had to think carefully about whether I wanted to plant them in separate "types" or not. Any selection or grading I do at this stage, however well-intentioned, risks screwing up my Mendelian ratios. And I'm relying on the ratios to give me information about the genetic makeup of the material I'm working with, which is how I decide how to proceed with it at the next stage. By looking at the Mendelian ratios (or lack of them) I will be able to work out which traits are dominant, which are recessive and which involve co-dominance between two opposing genes, and various other patterns.
In the end I decided the observations about seed type were important, or at least that it would be a shame not to try it and see, so I separated them roughly into eight different groups, one for each row of modules. It was entirely subjective, separating them into types when really they're all different. As I sorted through them they were all shouting "me me me!" But this is what I ended up with.
Row 1 - smooth, green, unspeckled
Row 2 - smooth, green, speckled
Row 3 - smooth, tan, speckled
Row 4 - wrinkled, unspeckled (of any colour)
Row 5 - wrinkled, tan, speckled
Row 6 - wrinkled, green, speckled
Row 7 - large, with indeterminate markings
Row 8 - smaller, with indeterminate markings
As I explained in a recent post, I'm looking for two recessive genes in this project, one for yellow pods and one for chunky sugarsnap-type pods, and my chances of getting both traits in a single plant are one in sixteen. Statistics are all very well, but the trouble is I can't just plant sixteen peas and be sure of getting one yellow sugarsnap. It doesn't work like that. So how do I know how many to plant? More statistics! I look it up in a chart in the back of Carol Deppe's book. According to that, if I want to be 95% certain of getting at least one yellow sugarsnap (where the chances are one-in-sixteen) I need to grow 46 plants. If I want to be 99% certain, I need 71 plants. My husband tells me the 95% threshold is perfectly adequate, but I have room for 64 plants in my root-trainer modules, so that's what I went with. It's useful being married to an academic scientist who can help me think out my experimental methods, but if I wasn't I would probably just sow the bloody lot and not worry about it.
I sowed the seeds last Thursday, and they germinated really quickly. The first seedling popped its head up less than 4 days after sowing, and by this morning (5 days) there were 30 seedlings visible, which is almost half of them. One thing I can say at this stage is that there's no correlation between seed type and speed of germination ... they're popping up equally happily in all the different groups.
Photographed this morning, the emerging seedlings
Posted by Rebsie Fairholm at 1:40 pm
Saturday, 23 February 2008
If you're thinking "What the heck is that?"... that's what I thought when I first saw what appear to be small rainbow-coloured potatoes on the Real Seed Catalogue's website, though I think actually my first thought was "I've gotta have some of that whatever it is!"
All I can really tell you about ulluco is that it's a South American tuber, grown and used in a similar way to potatoes even though they're not in any way related. It's not a well known crop in Europe. The only book on my shelves which has any significant information about it (three pages) is Simon Hickmott's Growing Unusual Vegetables.
What arrived in the package were several genuinely multicoloured tubers of varying sizes. Some were pretty small, but the packet says they will still grow into full sized plants. The small ones are all yellow, though one has deep pink mottling on it. Two of the larger ones are a solid orangey-pink with a dusting of dark pink spots, while the other two are a random swirl of muted yellow with deep emerald green, plus pink spots.
I left the tubers in their envelope and stashed them away in a cool dark cupboard for several weeks, but as advised I checked them for sprouts and by the beginning of this week they had got some definite signs of activity and I had to move them to a lighter place before they get too long and spindly. It's a little weird because they don't have such obvious 'eyes' as potatoes, and the sprouts seem to emerge out of nowhere. What's even weirder is that the colours are jumbled up. The yellow ones have bright pink sprouts and the orangey-pink ones and green ones have yellow sprouts with pink tips.
They come with the warning "BE VERY CAREFUL WHEN WEEDING as they flop all over the place and are often attached to the ground where you least expect." Fair enough. Apart from that, though, they're supposed to be reasonably easy to grow and to taste similar to potatoes.
Real Seeds are currently selling ulluco only as an experimental crop because it's not yet clear how best to grow it in the UK climate. It needs a long growing season and may only produce small tubers by the time the autumn frosts arrive. This is very much a voyage of discovery.
I know there are a few other bloggers who have already found and purchased some of these magic tubers so it'll be interesting to compare notes and ideas.
Posted by Rebsie Fairholm at 10:05 pm
Rants are like buses. There had to be another one round the corner.
It's been nearly two years since I wrote a post about F1 hybrids, and with the seed-buying season now underway it seems like a good time to revisit it.
If you browse through almost any seed catalogue, even those of ethical and responsible companies like the Organic Gardening Catalogue, you will see a lot of varieties with 'F1' next to their name. Most vegetables, with the exception of peas and beans, are extensively offered as F1 hybrids. There is a good reason for this: they are extremely profitable for the companies who produce and sell them. Sometimes they have benefits for gardeners too. But there's a catch. Well, several actually.
Commercial F1 hybrids are produced by environmentally dubious methods and they often need chemical inputs in order to grow properly. They're expensive, and they force gardeners to keep buying more packets year after year because you can't save true-breeding seed from them. They effectively curb the centuries-old sustainable practice of seed-saving and replace it with a cycle of marketing.
There is nothing wrong with F1 hybrids in themselves. They are the first step in every plant breeding project. When I breed my peas, I make my own F1 hybrids by hand-crossing different varieties and then use the resulting genepool to select potential new varieties. Nature creates F1 hybrids all the time, which is how plants evolve and diversify. It's a natural, wholesome and vital process. The problem lies in the commercial abuse of it.
The basis of F1 hybrids' popularity is hybrid vigour, or heterosis. When two dissimilar varieties are crossed, the result is a hybrid which will often be bigger, brighter, faster-growing or higher-yielding than either of its parents, which makes for a great selling point. But it's a one-hit wonder. Subsequent generations don't have the same vigour or uniformity, and the idea is that you don't save seed from it, you just throw it away and buy some more. This is bad for the plants, bad for the garden and bad for you, but the seed companies make a packet out of it and gain increasing control of what we buy and grow.
In my opinion, hybrid vigour is slightly overrated anyway. There's no doubt that F1 hybrids can produce abundant crops in the right circumstances, but so can natural open-pollinated varieties. You can make more of a difference to a crop's performance by providing decent growing conditions than by buying "superior" seed. I'm not convinced that the benefits of F1 hybrids are worth the costs.
One of the costs is that it's part of a push to industrialise seeds, giving corporations more control of what we grow. Industrialisation also involves taking seed production and plant breeding out of the field and into the laboratory, with patented technology increasingly seen as the path to profit. It's easy for me as an amateur plant breeder to condemn these practices, and I do understand how hard it must be to make a living from natural plant breeding - I don't expect to be financially compensated for the hours of work I put in on mine. But I still don't like the way things are going.
The problem in producing F1 hybrid seed commercially is that it's expensive. Hand-pollinating flowers is not difficult in itself, but it's time-consuming. One solution is to have the work carried out in countries where skilled labour is cheap. That may work with tomatoes, where hand-pollination is easy to do and a single pollination produces a large amount of seed. But it ain't much use with things like carrots, where the flowers are so tiny that hand-pollination is practically impossible. The only way to make F1 hybrids economically viable is to use Cytoplasmic Male Sterility (CMS).
The simplest application of CMS is to find a naturally-occurring gene for male sterility and breed it into your target crop. The plants are unable to produce their own pollen, which makes it easy to pollinate them en masse by exposing them to pollen from a different variety. Instant hybrids, in whatever quantity you want.
However, not all plants have been obliging enough to offer a male sterility gene, so it has to be done forcibly. One way of going about it is to use chemical sprays to prevent pollen being released. Another is the patented technique of protoplast fusion, where leaf tissue cells from different plants are fused (either with electrical current or chemicals) to transfer the male sterility attributes from one species to another. It's a method of forcing the transfer of genetic material between plants which don't naturally cross, although at the moment it only works with related species. The resulting plant tissues are tetraploid (i.e. they have double the normal number of chromosomes) and are propagated in the laboratory. It's not the same thing as GM, because it's a joining together of two complete and separate genomes rather than splicing genes from one genome into another. But some argue that it is a form of genetic engineering and should be labelled and regulated as such.
There are other problems with the production of commercial F1 hybrids. The parent varieties will usually have been inbred to an extremely unhealthy degree (because a lack of genetic variability is crucial to the uniformity of the resulting hybrid). Extreme inbreeding goes against nature and reduces genetic diversity. CMS (even in its "natural" form) has problems ... a male sterility gene used in maize hybrids happens also to convey susceptibility to a form of corn blight, which nobody realised until the blight started wiping out crops on a huge scale. Hybrids made by CMS sometimes produce sterile seed, so you couldn't save and replant it even if you wanted to.
But perhaps the most simple and straightforward objection to F1 hybrids: they are extremely poor value for money. Here's a few examples from the 2008 catalogues I happen to have lying around on my desk (try it for yourself):
Tomato Roma (non-hybrid) £1.99 for 75 seeds = 2.65p each
Tomato Suncherry Premium F1 £2.99 for 6 seeds = 49.83p each
Carrot Yellowstone (non-hybrid) £1.99 for 1500 seeds = 0.13p each
Carrot Purple Haze F1 £1.99 for 300 seeds = 0.66p each
Cauliflower All The Year Round (non-hybrid) £1.25 for 250 seeds = 0.5p each
Cauliflower Concept F1 £2.75 for 30 seeds = 9.16p each
Pepper Oro (non-hybrid) £1.49 for 45 seeds = 3.31p each
Pepper Attris F1 £3.09 for 5 seeds = 61.8p each
You will notice that catalogues disguise the price difference by varying the quantities in the packet. You may not worry too much about the difference between a £1.85 seed packet and a £2.85 one, but when the cheaper one contains 100 seeds and the expensive one 5 seeds, that's a huge differential, and one which they're hoping will slip beneath your radar. It's daylight robbery.
There are three ways you can help reduce the stranglehold big business has on garden seeds:
1. Boycott F1 hybrids, by choosing only non-hybrid varieties when you buy seeds.
2. Dehybridise them yourself: call the seed companies' bluff by saving and sowing seeds from F1 hybrids and selecting the best progeny, to create an open-pollinated version of the hybrid.
3. Make your own F1 hybrids. It's easy and fun!
Tomatoes are particularly suitable for home-made F1 hybrids. Choose any two non-hybrid varieties (the more unalike they are, the more fun the results) and when they are both in flower cross them manually (here's my easy guide to hand-pollination). Even from just two or three hand-crossed fruits, you can save enough seed to provide you with more than you can grow. Given that tomato seeds can easily stay viable for 10 years, if you like your hybrid you can keep sowing the seeds from the original cross for many years without having to redo the cross or save seeds from the hybrids.
There's never been a better time or a better reason to become an amateur plant breeder!
Posted by Rebsie Fairholm at 1:08 pm
Tuesday, 19 February 2008
Clear skies in February have two useful effects for me. Bright intense much-needed sunlight for bringing on my pepper seedlings indoors, and frosty photo opportunities in the garden.
My home-made coldframe against the back wall of the house. Bloody cat!
Frosted sage leaf
There go the crocuses. D'oh!
More home-made frost protection. That's not horticultural fleece, it's the old lady's net curtains (who lived here before us). Bloody cat!
It's been about three weeks since I started sowing peppers, and most of them are up now. Some of them aren't, but those were old seeds of dubious viability. If you're wondering why I'm sowing old and dubious seeds, they're rare and hard-to-find varieties which were being given away by Association Kokopelli, so there's nothing to lose by trying them. Not much luck so far unfortunately, but they can be very slow to germinate so I'm not giving up on them just yet. Another "nothing-to-lose" experiment is the sowing of seeds from supermarket-bought peppers. I don't like just throwing away the seeds, especially from fruits that taste good. There is a risk of them being F1 hybrids or simply unsuitable for the UK climate, but I'm greatly encouraged by the success David at Evington Hilltop Adventures had last year from an experimental sowing of Tesco's Finest red pointy peppers.
Among the sweet pepper varieties already romping away are Corno Giallo from Franchi, Lipstick, Kaibi Round, Napia and Orange Bell from Real Seeds, and Pimento Perfection from Association Kokopelli. I'm also growing a few chilli peppers, Lemon Drop and Pretty in Purple from Real Seeds and Bulgarian Carrot from Nicky's Seeds. I love chillis (I like to cut up a fresh one and put it in a cheese sandwich then sit there going "aaaaaaargh!" as the endorphins explode around my brain) but I can't handle them too hot and my husband won't eat them at all, so there's no point growing too many however tempting they are.
Sweet pepper seedlings. Kaibi Round and Orange Bell.
The recommended way to start off peppers is in a heated propagator, since they germinate most efficiently in warm soil. However, I haven't got one. But I do have two decent windowsills with radiators underneath them, so I sow the peppers in modules, stick a polythene bag over them and dangle them in a tray over the radiator, turning them periodically so that both sides of the tray get a fair spell of dangling. It's a bit of a fudge but it gives me good germination within 12-16 days or so. And the unusually clear and bright weather we've been having, with several consecutive days of strong sunlight, has brought them on a treat this year. One of the windowsills is east-facing and the other west-facing, so to get the best out of it I move the pepper trays from one to the other each day as the sun moves over the house.
The crucial thing about growing peppers in the UK is to start them off early. February to early March is ideal. You can also improve your chances of a decent crop by choosing early-maturing varieties. One advantage of buying seed from Real Seeds is that they have diligently tried out a huge range of peppers and only sell the ones which consistently do well in the UK climate.
Among my pepper seedlings this year I have one of nature's little oddities ... a seedling with three cotyledons instead of the usual two. It's a phenomenon I've often come across in tomatoes too. Does anybody know why this happens? I've just been reading up on it and there's a suggestion that it's a genetic variation, possibly caused by a recessive gene with incomplete penetrance (i.e. which doesn't always express itself). Usually (in my experience) when the next set of leaves appear they revert to the two-leaf arrangement and grow normally.
Tricotyledonous mutation: three seed leaves instead of two on one of my Pretty in Purple chilli seedlings. The dark colouring in the leaves is normal for this variety.
Another seedling issue which peppers and tomatoes both share, presumably because they both emerge from the soil in the same way (in the form of a loop which straightens itself out) is that the seedling sometimes emerges with the seed case still stuck on its head. Normally the seed case stays in the soil, but if the seedling doesn't free itself quickly enough the seed case dries out with exposure to the air and becomes very firmly stuck. Left to its own devices the seedling will either struggle its own way out or die. If you have lots of seed you can just discard any that do this, but if you're sentimental like me and want to help the seedling free itself, the solution is a used tea-bag. After making a nice cuppa, squeeze the tea-bag over the seedling to get a few drops of tea onto the seed case. Then leave it, and repeat as necessary to keep it moist until the plant frees itself. The tannin in the tea is thought to soften the seed case, and the water and warmth will do the rest. It needs to be done sooner rather than later though, or the rescued seedling will have lost too much vigour to be able to catch up.
Posted by Rebsie Fairholm at 5:38 pm
Sunday, 17 February 2008
(image copyright Greenpeace International)
I don't like to rant too often on my blog, but there's a new fuss kicking up this weekend about genetically modified crops in the UK, with two lots of bad news being reported in yesterday's Guardian. One, which wasn't actually news if you follow the various GM watching websites, but I'm glad the paper decided to highlight it, concerns the resumption of GM crop trials in the UK after several years of absence. The other, which IS news and pissed me off a great deal, is that the government is now thinking about keeping the locations of GM trials secret to thwart protesters. Opposition to GM in the UK is now so widespread that it's almost inevitable that crops will be trashed unless kept under 24-hour guard. It's quite clear that the public don't want them. So what's the natural response of our economy-worshipping government? Yep, let's raise two fingers to democracy and do it behind people's backs. The all-consuming satanic mills of Economy have to be kept grinding at all costs. Heaven forbid that Britain's businesses should miss out on the chance to milk the GM cash cow.
Around 1997 when genetically modified food first came knocking at Britain's door, I did a lot of reading on the science, the social and the environmental issues. And it horrified me. I became an active campaigner and harangued the supermarkets and politicians (including Michael Meacher, who was then Environment Minister and seemed to be a stubborn pig-headed supporter of GM, so it amazed me that he became a high profile anti-GM campaigner as soon as he left office). Tesco's responded to all my efforts by sending a standard letter about "cautiously welcoming" GM foods. When I wrote to them and complained that they were insulting my intelligence by repeatedly sending me their standard letter and not addressing my concerns they responded with ... you've guessed it. It seemed like nobody was listening. But then suddenly a de facto moratorium was put in place which essentially ended the threat of GM crops in the UK, at least for the foreseeable future. That was an amazing outcome. Consumer power, levered via the supermarkets, thwarted the big biotech firms and the government alike.
I remember in the 1990s how Monsanto (that's right, those nice friendly guys who gave us Agent Orange and PCBs) ran huge PR campaigns in the British press. Full-page colour adverts in magazines with pictures of green fields and luscious strawberries, explaining how they were going to save the developing world by introducing drought-resistant crops to the starving. These claims garnered a lot of sympathy, as world hunger was a high profile issue then (as it is now). But it was just propaganda. Most GM crops were (and still are) developed for herbicide-resistance, enabling farmers to blitz their fields with patented chemical poisons (purchased exclusively from the same companies, of course) and wiping out local wildlife and biodiveristy. Only a tiny proportion have been designed for use in developing countries, and as a patented technology it remains way beyond the financial reach of the people who need feeding. Starvation is largely an issue of poverty, not food shortage. Now of course they're jumping on the climate change bandwagon, trying to convince us that GM is the only way to secure our future food supply in a scary and changing world. More callous propaganda. The rush to push GM crops into developing countries has nothing to do with saving the poor, and everything to do with controlling and consolidating markets.
Then there was the rice contamination incident. Despite huge European consumer resistance to GM and the halting of field trials in the UK, an unauthorised and unapproved GM rice found its way onto the supermarket shelves and dinner plates of 15 European countries in 2006, including Britain. And whose fault was it? Well, it was a great example of how smartly the biotech firms squirm out of taking responsibility for the losses they inflict on others.
It's still unclear what happened, but somehow the American rice industry made a serious boo-boo. An experimental GM rice crop called LL601, which had been trialled for a few years but then withdrawn and never approved for use, found its way into 60% of supposedly non-GM rice grown in the US, which had already been exported all over the world before the contamination was discovered. The result was a disaster for the US rice industry. Orders were cancelled, products were rejected, imports of American rice were halted and farmers were left without income.
The company who developed the GM rice in question, Bayer CropScience, were baffled. The field trials of LL601 had ended in 2001, so how could it have caused such a colossal scale of contamination five years later? Unfortunately there was no way of tracing the original source of the problem because the records of the field trials were lost, destroyed, or inadequately kept in the first place. In a staggering act of corporate irresponsibility, Bayer simply declared the contamination an Act of God.
Nothing to do with us guv, the Lord Almighty cross-pollinated 60% of America's rice crops when we weren't looking.
So who is paying for the estimated $1.2 billion losses incurred by the incident? Why, the farmers of course! They're now pursuing class action lawsuits against Bayer CropScience, but there's no guarantee they will ever be compensated for this huge loss of income over something which was entirely not their fault.
In the UK, the official response to the incident was atrocious. Rice contaminated with LL601 was found on sale in Morrisons and elsewhere. The Food Standards Agency, which is supposed to be there to protect the public but enjoys a cosy relationship with big business, failed to issue a Food Alert, failed to identify the contaminated rice batches to the public, and initially (until threatened with legal action) told food retailers there was no need to withdraw the contaminated products from sale. They later had a thorough ticking off at an independent judicial review, but the damage was already done.
Most of my own objections to GM crops are centred on social, environmental and economic factors. I think GM is being used in the wrong way, for the wrong reasons, and will aggravate the already very serious problem of global food supplies being controlled by a small handful of increasingly powerful corporations. But I also have a lot of concerns about the technology itself. The basis for declaring GM food to be safe is the assumption that the crops are "substantially equivalent" to non-GM crops. That's one extremely dubious assumption.
Because of the emphasis on technology and innovation, it would be easy to assume that GM is done by a very precise and high-tech laboratory process. And in a sense it is, in that it's a specialised and expensive process. I'm not going to attempt a thorough explanation ... I'm a folk singer not a molecular biologist. But this is the gist of it. A sequence of genes is constructed in the laboratory, using several components: not just the gene for the desired trait, but also a "promoter" to switch on the gene, and sometimes another one to turn it off again. There will also be a marker gene, which most commonly is a gene for antibiotic resistance (the ethics of releasing antibiotic resistance genes into the environment is a whole topic in itself). This artificially assembled collection of genes, called a construct, then has to be multiplied with the help of a self-replicating bacterium, and then inserted into the host plant's genome. And this is where it gets difficult.
The way industry lobbyists talk about "snipping" a gene from one organism to another makes it sound like it's a precise science. If you had an image of a lab-technician, scalpel and petri-dish in hand, carefully taking a segment of DNA and meticulously slotting it into the host plant, well, it's nothing like that. Nature creates powerful barriers to stop foreign DNA getting in. It's done either with a "gene gun", which bombards the host's cells with charged particles carrying the artificial gene construct, in the hope that through sheer force some of it will bash its way into the cell's DNA. Or, more commonly, it's done by means of bacteria or virus which is used to infect the host plant with the construct DNA. Whichever method is used, it's totally random. There's no way of controlling what part of the host plant's genome the construct is inserted into, or which chromosome it will end up on. It could end up anywhere.
The assumption is that it doesn't really matter where the construct ends up. The technology is based on the principle that every gene is independent and just does one thing, so as long as it's in there somewhere, it will work. This idea goes back to Watson and Crick's dogma on the double helix in the 1950s. However we now know that that's an over-simplistic model. Far from being independent and single-purpose, genes often have more than one function and are often linked in complex and unpredictable ways. Inserting a gene construct randomly into the DNA of another organism can cause some genes to be deleted either side of the insertion site, and may break important linkages and inhibit the expression of other genes. The "gene gun" method often messes up parts of the host's existing DNA and inserts additional damaged fragments of transgenic DNA. GM technology takes no account of the possible effects of any of that.
Of course that doesn't mean that GM plants are inherently harmful. But it does mean they're inherently unpredictable. Random and uncontrolled genetic variability is one of the unresolved problems which GM crops are currently plagued with. For all the marketing hype about new technology and innovation, GM is essentially founded on outdated science.
How is any of this relevant to gardeners? Well, if crop trials and the eventual commercial release of GM varieties goes ahead, as seems likely, the inevitable spectre of contamination of garden vegetables has to be considered. And the government frankly doesn't give a toss. Under proposals drawn up by Defra, all land-owners within a certain distance must be informed when a GM crop is being grown. But that doesn't include domestic crops. Only commercial growers will be forewarned, leaving gardeners and allotment holders at risk of having their sweetcorn and other crops contaminated without their knowledge, and without any means of testing it. That's disgracefully unfair, given that many people choose to grow their own vegetables because they want to take control of what they eat and avoid the contamination associated with industrial food production. There will also be no warning to beekeepers or commercial honey-producers.
It's not too late. Consumer pressure worked a miracle in the late 90s. It can again if enough people believe in it.
There's lots of information about genetic engineering and its many issues on the Greenpeace International website, including some very detailed scientific briefings. UK-specific information can be found at GM Freeze. For a detailed explanation of the science involved in GM, try the Institute of Science in Society, a non-profit organisation which aims to make scientific information freely accessible to the public.
I'll say something for the Grauniad, they do make an effort to highlight and publicise these important issues, and I commend them for that. They have a whole bunch of GM articles and stuff on other related issues, like this FANTASTIC piece by Sue Branford from last week, Homogeneous Horror: A handful of companies now dominate world farming, with profound implications for genetic diversity.
Posted by Rebsie Fairholm at 11:20 pm
Friday, 15 February 2008
Seed tubers of Mayan Gold. Its shape tends to be more elongated than most potatoes. I can see a "lewd vegetables" post coming up later in the year when I harvest this lot ...
Oh gawd, I've got waaaaaaay too many potatoes this year. And just as I was chiding myself for overstocking to such a ridiculous extent I somehow managed to buy some more.
Well, I couldn't help it. I was in Dundry Nurseries outside Cheltenham (which as you may recall is Gloucestershire's mega spud emporium) just to buy some local eggs and a packet of pepper seeds (red bull's horn from Franchi, if you want to know) when I saw they had some Mayan Gold seed potatoes in stock. Last time I went it was on their list but they were still waiting for the stock to be delivered. I'm curious about this newly released spud and have been quite keen to road test it. It's a bit more expensive than other potato varieties but Dundry's price is lower than Thompson & Morgan's and they let you buy smaller quantities (I got 12). I don't know how special it really is, because when I search on the internet I find the majority of "information" about it is tainted with marketing bollux and I'm afraid I'm terribly cynical about celebrity chefs.
From what I can gather Mayan Gold was bred by the Scottish Crop Research Institute using an accession of Solanum phureja, a wild potato species found in Peru, as opposed to the usual Solanum tuberosum. The marketing claims it's an ancient variety, but I notice they've slapped Plant Breeders Rights on it, so presumably it's not that ancient. But anyway, a bit more genetic diversity in European spuds has got to be a good thing. Mayan Gold has elongated tubers with yellow flesh and sometimes a purple splodge on its rear end, although when you buy it as seed tubers it does of course just look brown and muddy. It's alleged to be high in carotene, which would account for its yellowy colour, but reading through the marketese it's not clear whether it contains beta-carotene (provitamin A) or one of the many other less nutritionally useful carotenes.
Unable to contain my curiosity, I cooked and ate one of the tubers. Now, it wasn't exactly a prime tuber nor a fresh one, so it wouldn't be fair to judge it on this one sample, but I have to say the taste was bland and the texture extremely dry and floury - the exact opposite of the advertised buttery texture and gourmet flavour. Really nothing special at all, just like an ordinary mediocre-flavoured spud. However, I'll reserve judgement until I've grown it myself and eaten it fresh ... it could be very different. Potatoes (and some other root vegetables) are a bit funny like that, they can vary enormously in different growing conditions and in different years, and will change even further during storage. I've tasted shop-bought Salad Blue potatoes which had all the charm of stewed sawdust, whereas the same stock grown in my garden had an outstanding flavour. Conversely, my home-grown crops of Marfona have never matched up to the exquisite flavour I've so often found in the mass-produced commercial packs in Tesco's.
Anyway, good old-fashioned Solanum tuberosum has a lot going for it, including some attractive variations in sprout colour.
Highland Burgundy Red
Posted by Rebsie Fairholm at 3:48 pm
Wednesday, 6 February 2008
The garden supervisor gets stuck into a hard day's work
This is the time of year when you have to do crappy jobs. There's no getting away from it. As I half-cripple myself bending over the half-dug earth tugging at little bits of couch grass root, I have to remind myself that I will be grateful for it in the coming months. Couch grass is the major hassle in my garden. No amount of careful digging and tugging will remove it completely, but I have to make this annual assault on it as a token gesture. This time of year it pulls through the soil relatively easily. It gets harder in a couple of months when it starts to gain vigour, and once the crops have started growing it's virtually impossible to tug it out without simply breaking the tops off and I'm stuck with it for the rest of the season, choking everything in its path.
The other pest plant I had to contend with when I moved here in 2004 is horsetail, but that seems to have subdued itself in the last couple of years. It likes poor sandy soil, so maybe as I've been adding loads of organic matter to the garden it's finding it less hospitable here.
Another crappy job arose this week which I wasn't expecting. I have a fairly large ceanothus tree next to the patio which the lady who lived here before told me she planted by mistake. She thought she was buying one of the nice little shrubby ones but it turned out to be the full-size tree jobby. It is beautiful when it flowers in May, but it spends the rest of the year casting a permanent shadow over next door's garden (luckily the bloke who lives on that side isn't a gardener, but I guess he would like to be able to see out of his windows) and pinging little black seeds into our dinner whenever we eat on the patio.
Its no fun being a ceanothus tree in England. Its thick evergreen canopy of fleshy little leaves is designed to resist the drying effects of the warm breezes of California, but the icy blasts of a British February send the poor thing swaying and heaving all over the place. There is a good reason why most native British trees lose their leaves in winter ... the wind blows straight through them and does much less harm.
Anyway, we've had some seasonable blustery weather this week, during which a large branch fell off the ceanothus. I've no idea what to do with it, so I just left it there for the time being. But then when I was standing on the patio gazing idly into the middle distance I heard a creaking noise, and realised that another huge branch, actually about a third of the tree, had split down the middle and was in the process of collapsing under its own weight. So I had to rush off to the shed and get a bow saw and hack as much weight off the branch as possible before it split right down into the trunk. Luckily I got to it quickly enough to save the tree from self-destruction, but I ended up crawling back into the house hours later with lots of cuts and scratches and my hair full of twigs, begging for a cup of tea. And I now have a massive pile of branches in the driveway. Still, ceanothus twigs make great pea sticks, which will come in handy for the truly preposterous number of pea varieties I'm planning to grow this year. And my next door neighbour will be astonished to find he has some daylight coming through his back window.
I've no right to complain really, because there's always someone who is cheerfully getting on with a crappier job than I am. Like Claire at Thankyou for the Days. Claire has taken on an abandoned allotment completely overgrown with brambles. When I say completely overgrown ... well, put it this way, when she started clearing it she found a couple of fruit trees she didn't know were there. But with a lot of determination and hard work she's already managed to clear enough ground to start planting, even if only a small amount at a time. I think she deserves a medal for her energy and resolve in taking on such a challenging project and I'm looking forward to seeing how the first season unfolds ... especially as she's planting lots of interesting heritage vegetables. Good for you, Claire!
Posted by Rebsie Fairholm at 8:54 pm
Sunday, 3 February 2008
F1 hybrid from my cross of Golden Sweet x Sugar Ann. They have pretty bicolour flowers which turn blue as they begin to fade.
Golden Sweet x Sugar Ann
I'm quite excited at the prospect of following this project, which is aiming to develop a beautiful sugarsnap pea with golden yellow pods. To my knowledge, there aren't any yellow sugarsnaps available. However I know this path has been trod before, by Dr Alan 'Shroom' Kapuler, who happens to be a hero of mine ... a pioneer of public domain plant breeding, such a rare thing in this era of Plant Variety Rights and gene patents, who has created open-pollinated versions of many popular commercial hybrids, and breeds vegetables for their nutritional value. The result of his experiment with yellow sugarsnaps was Opal Creek, which doesn't appear to be available at the moment, although there's a lovely and informative description of its creation in Carol Deppe's amazing book (pp. 130-135). I'm hoping I can create a yellow sugarsnap of my own, and I'm using one of the same varieties Alan used, the unique yellow podded mangetout Golden Sweet.
But funnily enough this project kind of started by accident.
I planted companion crops of Golden Sweet and Desiree for the purpose of crossing them, the first stage of the Real Seeds purple mangetout project which I'll be writing about separately. However, Golden Sweet turned out to be earlier-flowering than Desiree, by about 10 days. Rather than waste the first few Golden Sweet flowers (the best seeds generally come from the earliest flowers) I crossed them with whatever I had handy. The only other pea I had flowering in the garden at the time was the pint-sized sugarsnap Sugar Ann.
I think I hand-pollinated four flowers, which is not very many. Then it started chucking it down with rain for several days, so I couldn't do any more. By the time the rain stopped, the Sugar Ann had run out of flowers so there was no more pollen to be had. Then one of my four pollinated pods aborted and fell off. But the other three thrived to maturity. That gave me a few F1 hybrid seeds.
As they were the first of my 2007 crosses to mature (around the end of June), I decided I had time to squeeze another life cycle into the growing season, so I immediately replanted some of the seed in bog roll tubes. They grew like rockets.
I planted them outside in a 4ft high frame and they grew out of the top of it within a couple of weeks. They ended up about double that size and draped over the frame in a fold of luxurious foliage. The flowers were very pretty. One of Golden Sweet's peculiarities is that its flowers never fully open, although they go through spectacularly beautiful colour changes in their half-open state. This hybrid looked to all intents and purposes like Golden Sweet, but had fully opening flowers. It's likely there's a recessive gene involved somewhere in that, in which case I'll get a few non-openers in the next generation.
Talking of recessive genes, it's been well established right back to Gregor Mendel's experiments in the 1850s that tall genes are dominant in peas and dwarf traits are recessive. In most cases, if you cross a tall pea with a dwarf one, all the F1 offspring will come out tall. Then if you replant their seeds (F2) you should get about a quarter dwarf and three-quarters tall ... what's known as a Mendelian ratio. My hybrids have conformed perfectly so far. They were sired by a tiny dwarf pea barely more than a foot high, but they soared into huge plants. A bit of hybrid vigour made them even taller than their tall parent.
Another thing that's recessive, as I read in Carol Deppe's book and now know from experience, is the yellow colouring. I've made several hybrids with Golden Sweet now, and none of them show any trace of yellow at the F1 stage. Again the Mendelian ratio should apply, so I can probably expect the next generation from this cross to be a quarter yellow and three quarters green.
Then we have the sugarsnap edible pods. Edible podded peas have two recessive genes which (in combination) stop the pod from forming an inedible inner membrane. Both Golden Sweet and Sugar Ann are edible podded, so I assume they both already have this genetic combination. So far so good. Sugarsnap peas additionally have a gene which makes the walls of the pod thick and juicy. This is also recessive. So I will expect most or all of the F2 offspring to have edible pods (as both parents are of that type) and roughly a quarter will be sugarsnaps and the rest mangetout, or snow peas.
What I'm chasing here is a double recessive class. If we call the dominant green-podded gene 'G' and the recessive yellow-podded gene 'g', and the flat-pod 'F' and the puffy (sugarsnap) pod 'f', this is what we get.
Sugar Ann is genotype GGff - green and puffy pods
Golden Sweet is genotype ggFF - yellow and flat pods
The genotype for yellow puffy pods would be ggff. Two pairs of recessive genes. That's the combination I'm looking for.
When I crossed the two original varieties, the F1 hybrid will have got half its genome from each parent, so their genotype is most likely GgFf. I therefore expected all the F1 plants to have green pods, since green is the dominant gene (the yellow gene is still in there, but doesn't express itself in the presence of a dominant gene). I also expected the pods to be flat, mangetout types, as the dominant flat-podded gene will mask the presence of the recessive sugarsnap gene. And that's exactly what I've ended up with, so that's a good start.
From my F1 plants I collected lots of seed (just by letting them self-pollinate, as peas are entirely self-fertile). These are the F2 seeds, which I will be planting in about a month's time, and somewhere among them there should be some yellow sugarsnaps. About one-sixteenth of the crop, in fact. Here's why: I have a one in four chance of getting the recessive yellow pod colour, because there are four possible gene combinations: GG (green), Gg (green), gG (green), or gg (yellow). I also have a one in four chance of getting puffy sugarsnap pods, as the F2 seeds may carry FF (flat), Ff (flat), fF (flat) or ff (puffy). Multiply those possible combinations together ... and my chance of getting genotype ggff, both pairs of recessives in one plant, is one in sixteen.
These are of course just statistics showing the probabilities, and the actual numbers could vary either way.
Also, all the other genes are reshuffling at the same time, not just the ones I've singled out. And there are thousands of them. So although I can predict that roughly one in sixteen plants will be yellow sugarsnaps, I can't predict what other traits they may have. They may be tall or short, white flowered or purple-flowered, open-flowered or not-so-open. Any trait from either parent might express itself. And it's also very possible that other unexpected traits may show up that don't belong to either parent, as some genes are interlinked in funny ways and only express themselves in certain combinations. Ultimately I will have to see what I end up with and make my selections from there.
The F2 seeds. You can already see some diversity just in the appearance of the seeds. Some have the grey or tan colour and/or purple speckles inherited from Golden Sweet, others have the green seeds of Sugar Ann. Some are more wrinkled than others, which is an indication of their varying sugar content.
If you've been glazed over during the previous few paragraphs, don't worry. You don't have to understand the science to do these sorts of projects. You can just cross two plants you like the look of and see what happens. See my post on hand pollination for the practical instructions. Or you can wait till I grow mine and post some more photos!
Posted by Rebsie Fairholm at 1:59 pm