Tuesday, 30 September 2008

The joy of genes ... illustrated!

Patient readers who have put up with me banging on about gene segregation and F2 hybrids ... here's a little photo sequence from one of my breeding projects to show the process in action. I hope this will be a lot more interesting and meaningful than my simply talking about it, since it shows what amazing and beautiful diversity is locked up within every seed. If it inspires you to have a go at some hybridisation yourself ... so much the better.

OK, so these are pictures of pea seeds from my Yellow Sugarsnap project. It matters not what the objective of the project is or how close I am to achieving it ... this is just an illustration of what happens when you cross two varieties.

In this case I started off with Golden Sweet, an old heirloom supplied by the Real Seed Catalogue, and Sugar Ann, a bog-standard commercial variety from a garden centre.

The original parent varieties. Golden Sweet (left) has dimpled tan or grey seeds with purple speckles, while Sugar Ann has pale grey-green or cream seeds which are more wrinkled and slightly bullet-shaped.

So I made a cross between these two varieties, thus creating an F1 hybrid, and this is what the seeds looked like:

F1 hybrid between Golden Sweet and Sugar Ann

Sorry this is a bit of a small sample, but I'd already planted most of my F1 seeds by the time I took the photo. Anyway, you may notice that the F1 hybrid seed looks exactly the same as the original Golden Sweet seed. There's a good reason for that. The embryo hidden deep within the seed has the hybrid DNA made by the cross-pollination, but the rest of the seed (including its outward shape and colour) is the product of the mother plant. Therefore it looks just like any other seed produced by the mother plant. If I'd done the cross the other way and used Sugar Ann as the mother plant, then all the F1 seeds would have looked like Sugar Ann.

The next step was to grow the F1 seeds and collect seed from them, giving me the F2 generation. I didn't make any further crosses ... as peas are self-pollinating, all I had to do to obtain the F2 seed was to grow the F1 plants and allow them to produce seed naturally. This is the result:

F2 hybrid between Golden Sweet and Sugar Ann (i.e. the seeds from the F1 plants)

Hey up, now we've got something happening. The F2 seeds no longer look exactly like the Golden Sweet parent. In fact if you look closely they're all different. The differences are quite subtle but they vary in colour, size and shape. Some are wrinkly while others are smooth or dimpled. Some have purple speckles, others are plain. They show a jumbled up mixture of traits from the original parent varieties, caused by the random segregation of genes from both parents.

This is the point where plant breeding becomes immensely fun. Because every one of these F2 seeds produces a plant that is unique. And once again I don't need to do any crosses, I just grow the F2 plants and let them set seed naturally to produce the F3 seeds. And I get THIS:

F3 hybrid between Golden Sweet and Sugar Ann (i.e. the seeds from the F2 plants)

This is actually just a random sample, the first nine plants to reach maturity. There were many many more variations, but these few are enough to show you what's happening. I've saved seed from each F2 plant individually, and you can see that there is some consistency in the seed type for each plant, but HUGE variability between plants. Plant 58 produced seeds the same shape as Sugar Ann but a much brighter green and with purple speckles. Plant 02 produced seeds the same shape as Golden Sweet but green instead of tan. Plant 25 produced exceptionally wrinkled seed with no speckles. Plant 09 produced large round smooth yellow seeds which are totally unlike either of the original parents. Plant 14 shows some variability within itself but again a spectacular diversion from the original parent varieties, because the whole seed coat is sploshed with solid purple with a few bright greens and pinks thrown in.

Same image, detail

Every one of these packets of F3 seed is a brand new, unique variety in its own right. I could give them all names and launch them on the world. There wouldn't be much point doing so, partly because their offspring would still show some variability and further segregation (so they need to be stabilised for a few more generations first) but also because they won't all be worth pursuing. At a glance I'd say that Plant 09 with its big smooth yellow seeds is probably not going to taste good. In fact I did eat some of its seeds while they were still fresh and they were hard, mealy and bitter. By contrast, the exceptionally wrinkled seeds of Plant 25 indicate an exceptional sweetness, confirmed by taste tests, and that one is probably worth pursuing. Plant 37 also looks useful, as it has the supersweet ultra-wrinkled seed combined with pretty purple, pink and green colouring. There's enough interesting material here to keep me occupied for years. All from a single cross!

Anyway, what I hope this illustrates is that all these seeds are different from the original parent varieties in ways I couldn't have imagined when I made the cross. There are some familiar traits showing up, but also a lot of brand new ones which weren't displayed by either parent. And some of those brand new traits are really quite exciting.

What these pictures show is segregation for seed-coat colour and seed shape. Because in peas those two traits are readily observable. Of course the same level of segregation is happening to ALL traits right across the genome, with potentially millions of different combinations. I hope this gives some idea of how much diversity and scope for new varieties is possible just from making one simple cross-pollination.

Sunday, 28 September 2008

Goddess tomatoes and seasonal joys

A plethora of newly harvested heritage beans

With all the crises I've been dealing with over the summer, the garden has been badly neglected this year. To the point where I'd be embarrassed to let anyone see it, even a non-gardener. I've managed to look after the crops OK, but I didn't keep on top of the weeds earlier in the season and they've got themselves well entrenched. And I had to steel myself to go out there and start dealing with them today, because I'm making a change to my gardening method this year.

Normally I allow the garden to biodegrade gracefully in its own time over the winter. It's partly laziness and partly hippy idealism. My reasoning is that by leaving a tangle of last year's decaying crops on the land over winter I'm providing shelter for overwintering insects, seeds for birds to eat, and ground cover to protect the soil, and by January it's all nicely broken down and easy to dig in ... a nice bit of organic matter to enrich the soil. But in the last couple of years it hasn't worked out so well because it also provides the perfect overwintering conditions for slugs and snails, whose numbers have erupted out of control over the course of two wet summers. So I'm afraid this year I'm clearing it all and the wildlife will have to find somewhere else to shelter. I'm hoping the birds and frogs will quickly gobble up the snails, or else they'll bugger off into next door's garden (where he doesn't actually grow anything so they won't bother him).

But I do have quite a task on my hands. It's a case of: Hmmm, I'm sure there are some gooseberry bushes somewhere over here under these swathes of long grass. I'll just carefully insert a gloved hand and OOOOOOOWWWWWW FUUUUUUUUUCK! Oh yes, there's one.

One thing that will directly benefit the wildlife (birds, mice and slow worms anyway) is the continued incapacitation of the Ginger Peril. We had another crisis recently when his bandage slipped and reopened his operation wound, which had to be stitched up again. And of course it had to happen on a Sunday, requiring a trip to the emergency out-of-hours vet, who charged £113 for a temporary bandage to last him until the morning. It also meant an extra two weeks in the cage, bringing his confinement time to 6 weeks. But he does look cute in his little plastic bonnet.

Most of the harvest is safely gathered in now. The last of the bean crops are now drying indoors, as seen below. The dark curvy ones on the left (and shelled out in the bowl) are Major Cook's Bean, which I'm growing for the Heritage Seed Library as part of their Seed Guardians scheme, and which has been so spectacularly prolific it's going to cost a small fortune to post it back to them. Look out for it in next year's catalogue, it's a corker. I've posted a full review of it here. In the middle are the dried out pods of the similarly abundant Poletschka (thanks Celia) and to the right some green-yellow San Antonio from the Heritage Seed Library, which also did well for me.

The area you see here spread with beans is the bed in the spare room. Needless to say we don't have many guests to stay at this time of year.

You will notice that I harvest bean pods for seed-saving as soon as they're mature, and dry them indoors rather than leaving them outside to dry on the plants, as is often recommended. The reason for that is the unpredictable weather, which can ruin an otherwise excellent crop if the rains decide to come down heavy in September. This year they haven't, and September has turned out to be better than August, but I wasn't taking any chances. It does no harm to harvest them at this earlier stage, as the plants have already given them as much nourishment as they're going to get. It is important though to keep them well ventilated, ideally by spreading them out so they aren't touching, and turning them regularly. If you don't, they can easily go mouldy.

And no harvest would be complete without a parade of weirdness. And so I proudly present my Threefold Goddess Tomato. She's taken her time to ripen, but here she is.

The bottle-top is for scale (gave me an excuse to crack open a beer anyway)

She is the Divine Feminine expressed in fruit. She is essentially three tomatoes fused together in harmonious symmetry, born out of one flower with an unusually wide stigma, and endowed with various crevices and hollows which look a bit ... erm ...

Anyway, she was the first fruit produced by an exotic variety called Orange Strawberry which I grew in my greenhouse. It's an oxheart type, which means it's large, heart-shaped (normally it is, honest) and exceptionally fleshy inside with very few seeds. It's really a cooking tomato, and has a wonderful flavour when cooked as well as this glorious bright orange colour. See here for a full review. Not one you'll find in garden centres ... I got my seeds from Association Kokopelli.

Friday, 26 September 2008

Heritage vegetable review
Tomato: Green Tiger

Age: don't know ... information is scarce
Background: a supermarket tomato which has made an impact with resourceful gardeners
My supplier: Marks & Spencer
Pros: beautiful, prolific, tasty, holds up fairly well against blight
Cons: none

OK, so Green Tiger isn't really a heritage variety at all. At least I don't think it is. Reliable information about it is extremely scarce, so I don't really know where it comes from. Marks & Spencer have been selling punnets of this fruit in their UK supermarkets claiming that the variety is exclusive to them, and you certainly can't buy the seeds anywhere. But I was quite impressed with it, so I saved seeds from it to grow myself. As I googled around for more information (unsuccessfully) I came across a lot of other gardeners who have saved seed from it and are growing it for themselves. So it is, in a sense, a "folk tomato" ... introduced for non-gardening commercial use and spontaneously taken over by the people.

I first saw it in my local branch of Marks & Spencer's in 2006 and was attracted to its unusual appearance. It stood out a mile among the boring red homogenised tomatoes ... a deep red rounded fruit with a glossy skin and dark olive green stripes. I do commend M&S for their commitment to trying out new and unusual things, and this is undoubtedly the most interesting tomato I've ever seen on a supermarket shelf. I couldn't resist buying a punnet of them, and they tasted pretty good. Not the best I've ever had, but good enough that I wanted to try growing it. Commercially grown fruit is never in its prime, as it's usually picked prematurely and chilled to within an inch of its life. So if a supermarket tomato tastes good, it should taste better when home grown. The shop-bought fruit had been grown in Kent, so obviously could cope with the British climate.

Of course the down side of saving seed from supermarket fruit is that you don't have any idea whether or not it's an F1 hybrid. If it is, it won't come true from seed. Not that that's necessarily a problem. Last time I took a fancy to a "Marks & Spencer's exclusive" tomato, Pink Jester, it did turn out to be an F1 hybrid and there was a lot of variability in the seeds I saved. Some were very like the original though, and others were slightly different in shape but had an even better flavour. So I've been happily growing out the F3 lines ever since, and I'm glad I saved seed from it when I did because it soon vanished from the shops. I expected much the same situation with Green Tiger ... hoping it might be an open-pollinated variety which would breed true, but prepared for the likelihood that I'd get a weird mish-mash of types and would have to select the ones I liked.

The first attempt to grow it in 2007 was a failure, because the blight struck incredibly early and destroyed all of my outdoor tomato crops before they'd even set their first fruits. In 2008 however, armed with a newly erected greenhouse, I got a superb crop. Two more plants grown outdoors did less well, producing lots of fruit but struggling to ripen them, so I'd suggest this variety is better suited to greenhouse culture. But the important thing is, all three plants were essentially the same as the original and each other. Green Tiger is a proper open-pollinated variety! Yay!

Green Tiger plants have broad leaves of a very dark green, and the leaves have rounded edges. It's quite an elegant plant compared to yer average tomato. Growth is indeterminate, but not exactly rampant. It took all of the season to reach the roof of the greenhouse, and one I grew in a pot on the patio remained quite bushy and compact.

Flowers are small and star-shaped with a slight dark blush on the petals. They grow in short trusses with chunky peduncles bent at rightangles. The calyx is a dark green star, broad and chunky.

Young fruits are a bright emerald green, shiny and spherical. The stripes don't start to develop until they're close to reaching full size. The earliest fruits are about the size of a golf ball, but later ones are more cherry tomato sized. As they near ripeness the green stripes darken, and the rest of the fruit takes on an orangey-brown hue, eventually ripening to a deep dark burgundy red with a more bright and intense red at the top of the fruit (hidden under the calyx, so you only see it after picking). The green stripes stay green, and are kind of mottled. It's an unusually dark green, like a very dark olive.

The surface of the skin is very shiny and attractive. Like most commercial varieties, it has quite a thick skin and stays very firm even at full ripeness. This is what commercial growers want, to enable it to withstand packing and handling. The advantage it has to gardeners is that the fruits are fairly resistant to splitting.

Cut open, the flesh is thick and the fruits hold their shape well ... not at all squashy even when fully ripe. The colour is a deep dark red, darker than most tomatoes, and presumably this means it has high levels of beneficial lycopene. There are two locular cavities with plenty of seeds and the gel is a dark green infused with red.

Flavour is good ... just what you want for an eating tomato. It has a rich and full flavour with a nice balance of sweet and sharp.

In my greenhouse, Green Tiger was the variety that held out best against blight. That's not to say it's blight resistant ... it isn't ... more blight tolerant. The leaves succumb in the usual way but the fruits seem to keep going without any problems. Consequently I got a very good yield from it and was able to keep picking fruits over a long period, even as other varieties keeled over around it.

I'm still curious about where this tomato comes from. It was apparently introduced by Bernard Sparkes, a farmer in West Lancashire, but it's not clear whether he bred it himself or brought it in from elsewhere. Marks & Spencer's are marketing it as their own "exclusive" variety, but I wonder what that actually means. Did they commission it? Or does "exclusive" simply mean that they're the only store currently selling it? Is Green Tiger its real name, or just for marketing purposes? I'm a little sceptical about the names and claims made by supermarkets. But certainly this variety doesn't seem to be available in garden centres or seed catalogues. If it really is an exclusive it may well have Plant Breeder's Rights on it, in which case tough shit because it's already doing the rounds at informal seed swaps across the UK.

I'd definitely recommend this. Whether you pick it up through a seed swap or scrape some seeds out of a supermarket fruit (not sure if they're still selling it, and if they are it's only a limited season) it's well worth giving it a go.

I'm changing the way I post Heritage Vegetable Reviews ... they will soon be available all together on their own website. Watch this space!

Monday, 22 September 2008

Saving seed from tomatoes

Tomato seeds for future generations, in pulps of all colours. Banana Legs (left), Black Prince (top), Douce de Picardie (right), and Caro Rich (bottom).

Bugger the credit crunch ... you need never pay for a packet of tomato seeds again if you adopt the age-old practice of saving your own. Even a single fruit will yield enough seeds to last you for years (or to share with your friends) and they can quite easily stay viable for 10 years or more, so it's really well worth doing. As tomatoes are naturally inbreeding and self-pollinating, you can get away with growing a small number of plants and saving just a small number of fruits. If you save seed from F1 hybrid varieties they won't come true to type, but the results can be interesting in their own right. Many commercial F1 hybrids are a rip-off anyway, unless you want to use them to develop your own versions.

There are basically two ways of saving seed from tomatoes. The recommended way is to ferment them in their own gel, which works very well but is a little fiddly and icky. And then there's the quick bodge-job method, which is often frowned upon but works perfectly well in my experience. Personally I use both ... the proper method for larger amounts (saving seed from two fruits or more) especially if I intend to give them away to others, and the bodge-up method for small amounts (one to two fruits).

Either way, the ideal thing is to use tomatoes that are over-ripe ... past the point where you'd want to eat them. I often compromise by using only slightly over-ripe fruits, cutting off any bits which have gone manky and stewing up the remainder in a pan with olive oil to make a lovely sauce. That way nothing gets wasted. You CAN save seed from tomatoes which are still green, but the less mature they are the more risk there is that the seeds are immature, in which case they may not germinate.

If possible, avoid saving seed from plants suffering from blight. I say "if possible" because frankly the blight problems have become so bad in the UK it's almost impossible to grow a totally blight-free crop these days. If you have a plant you really want to save seed from and it has blight, save seed as early in the season as you can (even if the fruits are not fully ripe) and choose the least affected fruits.

Even with the more elaborate method, saving tomato seeds is very easy. Just try not to use the unladylike language I did this morning when I dropped a load of partially dried Caro Rich seeds all over the carpet (it had to be a beige carpet, didn't it?)

The fermentation (recommended) method
Slice open your chosen fruit(s) and spoon out the seeds, complete with their surrounding gel, into a small jar or container. Clear glass is ideal so that you can see what's going on in there during fermentation, but any container will do ... a jam-jar or a plastic yoghurt tub. The little glass dishes you get with overpriced puddings from Waitrose are ideal. Whatever you use, it needs to be narrow enough to create a bit of depth when you put the seeds and gel into it. Most people add a small amount of water. It doesn't make a lot of difference either way, but a bit of water seems to help things along. Use a separate dish for each variety you're saving seed from (that should be obvious but I'd better say it anyway).

Cover the jar with a scrap of foil and leave it somewhere like a windowsill for about two to four days.

After a day or two you should notice some changes happening in the jar. Bubbles, for one thing. They may not be active fizzy bubbles, but there should at least be some bubbles hanging around in there. The other thing you'll get is a hideous crust of mould over the surface. This is entirely normal and should be left undisturbed.

I'm fascinated by the diversity of mould that appears on tomato pulp. Sometimes it's a pale waxy yeast-like gunge over the surface, and sometimes it's more bluey patches, or little white hairs. Occasionally you get the whole jar filled up with soft dry fluffy stuff like grey candy floss, which flexes to the touch like a delicate sponge.


After a few days you can tip the yukky stuff out and retrieve your seeds. It's difficult to give a time scale for when to do it, it's not a precise science. Allow the mould to grow right over the surface, and it should be ready shortly after that. The main thing is not to leave the seeds fermenting too long, or they will start to germinate and be ruined. Fermentation happens much faster in warm conditions, and can be ready in as little as 24-48 hours in a hot climate. More usually though (in European countries) 3, 4 or 5 days is about right.

When you're ready to decant the slop, the first step is to gently peel back the mould layer with a teaspoon. Sometimes it just peels back as easy as anything like custard skin, other times it's more irksome. Either way, there will probably be some seeds sticking to the underside of it. You have two options at this point. You can go "uuuuuuuuurrrrrrgh!" and lob the whole lot straight in the bin. Or you can carefully hold the mould disc aloft and scrape the seeds off with a teaspoon. It all depends on how precious the seeds are and how squeamish you are about mould.

Once it's denuded of its mould layer, slop out the contents into a fine-meshed sieve or a tea-strainer, and gently wash it under a slow-running tap. It can take a bit of rubbing to get rid of all the fleshy pulp, but eventually you should be left with a strainer full of nice clean wet seeds. I usually leave them to dry in the tea-strainer, but you can dump them out on a plate. It's not a good idea to put them onto kitchen roll or paper because they may stick to it, though it's OK to put the strainer down on top of some kitchen roll. Either way, the seeds will clump together as they dry and it's a good idea to give them an occasional rub to separate them.

Within a few days you'll be left with the familiar cute fluffy little seeds ready for packeting up.

If you're saving more than one variety, take care not to muddle them up. Most are impossible to tell apart. Make sure there aren't any seeds from a previous batch clinging to the sieve or teaspoon.

Why go to all this bother, you may ask? Well, the gel around the tomato seeds contains a chemical to inhibit germination (very useful to prevent the seeds germinating within the fruit as it ripens). The fermentation method mimics nature's processing of the seed by breaking down the chemicals in the gel, making use of the naturally occurring Oospora lactis which is responsible for the rapid rotting of fruit, and enabling the seeds to germinate freely. In the process it rids the seeds of many bacterial diseases.

The Quickie Bodge-Up Method
Just scrape the seeds out of the tomato straight onto a piece of kitchen roll (paper towels in the US). Spread them out as thinly as you can, and leave the sheet somewhere well ventilated for a few days to dry. Write the variety name on there, fold it up and store it in a seed envelope.

Here's one I prepared earlier

The seeds will be stuck glue-like to the sheet and may not ever want to come off, but that's OK, you can just tear round them at planting time and sow them with the paper still attached.

This has got to be one of the easiest seed saving methods around. It has two potential disadvantages. One, it doesn't kill off any bacterial diseases that may be lurking around the seeds, and two, it doesn't remove the chemical that inhibits germination. But in practice it isn't usually a problem. I've never had any germination problems with seed saved in this way, and they stay viable for years. Maybe the chemical does break down on the kitchen roll by the time you're ready to sow the seeds. The threat of seed-borne disease is small if you select fruits from healthy plants. So if this is really the only way you'd want to save tomato seeds, go for it I say.

Sunday, 21 September 2008

Oxford - the bloggers' big day out

What finer setting could you want for a real-world get together of garden-allotment bloggers than Oxford University's beautiful Botanic Garden? The tower looks like it's rising up out of that building but it's actually the Magdalen College tower on the other side of the road.

Apart from me there were: Bifurcated Carrots - Veg Plotting - Spadework - The Plot Thickens - Fluffius Muppetus - Soilman - Manor Stables Vegetable Plot - Mustard Plaster - Hills and Plains Seedsavers - The Real Seed Catalogue

And here we all are, assembled in the corner of this beautiful historic garden.

Guest speaker Ben from Real Seeds 'urns' the respect of the assembled bloggers as he shows the various points where crops were domesticated along the agricultural blue nylon timeline. Seen stretched out like this, it really brings it home to you how much history and how many centuries of work and care have gone into every seed we have today.

And he continued to enthral everyone with his knowledge and enthusiasm as we enjoyed lunch on the lawn, replete with multi-coloured tomatoes, apple pie and exploding cucumbers. In fact, Oxford University's vegetable collection wasn't half as diverse and exciting as the contents of Patrick and Steph's home grown tomato bowl.

Emma (Fluffius Muppetus) photographs Michelle (Veg Plotting) and Kate (Hills and Plains).

There's never any shortage of things to look at in the Botanic Garden ... like this incredible lily pond.

Or this rather nice banana leaf.

The greenhouses were somewhat bigger than mine ...

And the flower borders somewhat tidier...

And neither is my greenhouse overlooked by dreaming spires, but you can't have everything.

I still think we could teach 'em a thing or two about vegetable diversity.

Many thanks to Patrick for all the work he put into making this meeting a success and a pleasure.

Saturday, 13 September 2008

Aaaargh, what a summer










