Friday 27 October 2006

A not so happy resolution

Unfortunately we've lost the battle to save our cat, Bob. We always knew there was a risk he would deteriorate again when he came off the dialysis but he made such a good recovery after the last lot of treatment we had high hopes he would pull through. But he wasn't looking so good last weekend so we took him in for another blood test on Tuesday which confirmed that the treatment wasn't working. So it was just a case of deciding when to let him go.

Ian had a long chat with the vet on the phone yesterday about how and when to make these decisions (though we have plenty of experience already ... this is our fourth cat bereavement in three years). The vet is in the same situation himself: his own dog is seriously ill but so far he and his wife (who is also a vet) haven't been able to bring themselves to put him down. There's no fixed right or wrong answer but we wanted to keep Bob going for as long as he was happy. By this morning he had deteriorated to the point where we felt that line had been crossed.

We'd only had him for two years, having adopted him as a 10-year-old (though I have my suspicions he may have been older than that) because we're softies when it comes to the old and shabby cats that nobody else wants. Bob had been in the shelter for over two months and looked a bit of a mess, very overweight with a bald patch down his front where he'd had surgery. But he had such a lovely personality (and loud purr) we wanted to give him a chance, and he turned out to be a real delight to us. So at least he was spoiled rotten for the last two years of his life.

Monday 23 October 2006

Update on the purple pea project

My hand-pollinated hybrid pea reveals its flower colour. Innit lovely?

Well, plant breeding may be a complicated pain in the neck, involving a lot of poking of flowers with scalpels and potentially years of patience and careful study, but I reckon there's no greater gardening thrill than to see one of your home-made hybrids burst into flower for the first time ... and find out what colour it is.

I'm getting immense pleasure just from looking at these large flamboyant purple-pink flowers, created by me, on a garden vegetable which normally has quite unexciting flowers. They are so beautiful.

The pods are turning colourful too, after a fashion. They're not as decisively purple as a true purple variety, but they're purple nonetheless. The flower buds start off a pale creamy pink with the maroon inner petal just showing through, then open out into a lovely two-tone pink which gradually matures to blue.

And so far my hybrid is following the pattern I predicted from what I know about the genes involved in pea colouration.

Just to recap on what this project is all about: I'm trying to breed my ideal garden pea. The basic spec is for all the fine qualities of a 19th century variety called Alderman, but with pink or purple flowers and purple pods instead of the usual white and green. Alderman has large white flowers, grows from between 6 to 8 feet tall and has the most exquisitely sweet and juicy peas (when eaten raw) that I've ever tasted. I couldn't tell you what they taste like cooked, because I've never got any as far as the kitchen. They taste too good straight off the plant. The peas are also huge in size and stay sweet even when fully mature. It's a fabulous variety and well worth seeking out.

To start my quest for a colourful version of Alderman, I did some crosses earlier in the year using Alderman flowers hand-pollinated with pollen from Mr Bethell's Purple Podded, an heirloom pea with pretty two-tone pink flowers and purple pods, which I got from the Heritage Seed Library. Its actual peas are green and reasonably large and pleasant tasting, but I'd be lying if I said they had anything like the ambrosial sweetness of a good green-podded pea like Alderman.

Usually when you do a plant breeding experiment you just have to try things out and see what happens, because very little is known about most of the genes in most plants. Peas have been better studied than most because their genetic patterns are very uniform and simple ... which is why they were responsible for the discovery of the fundamental laws of genetics. But even so, not all the genes have been identified. I have no idea what genes (or groups of genes) are involved in the production of Alderman's sweet flavour, so all I can do is grow my hybrid for several years and do loads of very thorough taste tests in each generation to find the flavour I want (it's a hard life).

But things are slightly easier when breeding for colour, because those genes have been identified and named. If I want plants with purple pods and a purple flash or ring in the leaf axils, there are four genes I need and they're all dominant. Gene A is the crucial one that gives the plant the ability to synthesise anthocyanin, the pigment responsible for purple colouring in most vegetables. A is effectively the 'on' switch for purple, but it doesn't control where the colour is expressed within the plant. To get purple pods, I need two additional genes, Pu and Pur (no I'm not making these up), and to get the purple splash at the base of the leaves I need another gene called D. A plant may carry genes Pu, Pur and D and have no purple colouring at all, because these genes can only express themselves in the presence of gene A.

I've made the assumption that Mr Bethell's Purple Podded has all four genes, A, Pu, Pur and D, because it has purple pods and purple leaf axils. And I also assume that Alderman, being green podded and green leaved, doesn't have A, although it may or may not have any of the other three genes. Therefore, when I make a cross between these varieties, I expect the F1 hybrid (that's the first generation of seed from the cross) to have purple pods and purple leaf axils. Why? Because they will inherit one half of their genome from the green podded variety and one half from the purple podded, and in this case the genes in the purple variety are dominant.

And so far that's exactly what I've got, which suggests that my hybrid pea, as well as being beautiful in its own right, has all four of the genes I want.

At first it looked as though the plants were going to produce green pods, because they were quite slow to change colour. With most purple podded peas, the baby pods start off green with a purple strip along the top edge, and then the rest of the pod colours up when it's a couple of days old. My hybrid variety is taking a couple of days longer to turn purple than I would normally expect, and the colour is slightly patchy on some of them. It's too early to draw any conclusions about why that's the case ... but it may be that the dominant purple pod genes are competing with another dominant gene for green pods, resulting in co-dominance and a colour part way between the two.

I haven't yet found out what genes are involved in the flower colour, but my guess is that they too are dominant but reliant on the presence of A. I'll know more about that when I grow the next generation. The flowers on my hybrid are basically the same colour as the 'father' plant, Mr Bethell's Purple Podded, but they're larger (an Alderman trait) and they have a very flat standard petal (that's the wide one at the back) which is a characteristic not seen in either parent. Most intriguing.

More intriguing still, one of the plants has started producing two flowers at each node, when both of the parent varieties produce only one. (There is a purple podded pea which does have paired blooms at each node, Ezetha's Krombek Blauwschok, but I didn't use that variety in my cross.) Presumably there is a gene for two-flowers-per-node which was being carried, but not expressed, by one or both of the parents.

But anyway ... aside from the joy of seeing a new hybrid come into flower, it doesn't really matter how beautiful the plants of this F1 generation are ... they will not be the same in the next (F2) generation. Those two halves of the genome will be broken up and randomly recombined, so that different genes from either of the original parents will start to show up in the offspring, with a huge number of different combinations possible. That's where you get the opportunity to choose the ones you like as the basis for a new variety. So the purpose of my growing these plants is just to obtain as many (self-pollinated) seeds as possible for the next generation, and those seeds will show a mixture of green pods and purple pods, from which I will select the best purple ones.

And while we're on the subject I must publicly thank Silvia (of the Windywillow blog) for the beautiful artwork she did based on my purple podded peas and my complaint that the faeries were coming along in the night and stealing the gold threads I was using to tag my hand-pollinated buds. Though in fairness to the faeries, they rarely actually steal things ... things disappear but nearly always turn up again, albeit in odd places. My missing gold threads turned up about three days later on a different plant, so it'll be interesting to see what happens when I plant the seeds from that batch. Silvia's artwork shows a couple of very smug-looking faeries tugging the threads off the flowers and is really wonderful ... she's very talented.

Sunday 22 October 2006

Gah! One thing after another

Sorry for yet another period of inactivity ... husband has now done his back in and we also have a very unwell cat. We nearly lost the cat last week when he collapsed with kidney failure but our wonderful vet pulled him back from the brink ... we now just have to wait and see if he gathers strength over the next few days.

I shall be posting an update on my pea-breeding experiment very soon though, because my F1 hybrid is now flowering, which is very exciting ...

Sunday 8 October 2006

Blight, blight, blight, blight and more blight

Lovely orange Tangella tomatoes, ripened on a windowsill after blight killed off the plants

Long time no blog ... apologies for the break. We've been having a rubbish time recently ... my husband has been ill for weeks, his mum's been even more poorly, and I'm exhausted. It's also been a turbulent time with the music 'career' and my band has now officially broken up. It wasn't entirely unexpected, but it has meant a lot of time spent on trying to salvage as many songs as I can and launch myself as a solo artist. Things are looking up ... the record label have given me my own page on their website and I sang a song on a new EP by The Owl Service which was released this week.

The garden looks pretty depressing at the moment. But I guess that's normal for this time of year.

Cold nights are bringing out some beautiful red and purple streaking on these Meraviglia di Venezia pods, which are normally just yellow

The beans are mostly over. The runner beans (Black Magic) are now just a few bedraggled pods. Meraviglia di Venezia has not done well this year, and I'm beginning to feel that this variety isn't a good choice for the British climate. A weekend of blustery wind in September absolutely shredded it, and it hasn't recovered. Many of the pods have no beans in them at all, just a floppy leathery pod which soon shrivels. As the nights turn colder it's beginning to show some quite attractive purply-red streaking on the pods, which is very pretty but doesn't make up for the poor yields. Kew Blue has been much more impressive, and kept flowering and podding right up until the middle of of September when it suddenly realised it was autumn and dropped dead overnight. I had good yields of yummy pods from it though, so no complaints. Mrs Fortune's, by contrast, is still resolutely flowering and setting pods. It looks a bit tatty, but it's soldiering on.

Autumn colours start to show as chlorophyll breaks down in the leaf. The leaves on Kew Blue beans produce an amazingly vibrant violet-pink.

But the most significant change in the garden is blight. Blight absolutely bloody everywhere. Britain's most popular fungal infection, and the horticultural equivalent of the Black Death. I had to destroy almost all my tomato plants just as they were starting to ripen up, and I reckon I've lost about 70% of my crop this year (in 2004 it was 100%). Some have ripened up OK indoors, but many more have rotted. That's the horrible thing about blight, even things which look perfectly healthy when you pick them quickly succumb, because the infection is insidious and invisible.

Not all the plants were affected in the same way. Clementine was the first to be attacked, but it spread slowly and the plants carried on fruiting for a further two weeks. Tangella remained blight-free until quite late in the season, but when it did catch it the plants were a blotchy rotting mess within two days. And because it was the latest maturing of all my tomato varieties the fruits were still all green. I did manage to salvage a dozen or so by picking them early and ripening them indoors on a windowsill. Funnily enough my potato crops stayed blight-free much longer than the tomatoes, although they have been destroyed by it now.

The only remedy available to organic growers is copper fungicide, which is poisonous enough in itself ... but I found it completely ineffective this year. It didn't even slow down the spread. Blight patches treated with the copper spread out and produced spores just as readily as untreated areas. According to Alan Romans' lovely Potato Book, the blight problem is getting worse for several reasons. We used to have only one type of blight in Europe, whose spores only reproduced asexually. But thanks to a consignment of infected potatoes a few years ago we now have a second type, which has been breeding with the first type to create new strains which quickly adapt and mutate, not only to resist fungicides but to overcome blight resistant plant varieties. The warm moist weather brought about by climate change gives blight even more of a boost.

He also says that the blight fungus evolved from a seaweed, which is a strange thought.

A few Black Plum tomatoes survived long enough to reach full ripeness.

But one single solitary tomato plant is still out there in the garden, still with green fruit, but still (so far) unblighted. It's one of the American varieties I bought from a US supplier and which isn't available over here: Isis Candy. It doesn't have a lot of fruit on it, but amid the mayhem of disease and destruction there it is, still sitting there, growing its fruit. I don't know whether it's a blight-resistant variety or whether it just got lucky. But I'll certainly grow it again next year to find out.

Many thanks to everyone who has left comments or emailed me during my absence ... I do really appreciate it even if it takes me a while to respond.