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Post by steve1 on Dec 2, 2015 16:48:16 GMT -5
Interesting Raymondo. I quite enjoyed Yakumo for taste, but as the seeds swelled parchment reared its head. Full parchment in my line from diggers. Oh, and it looked like a Christmas tree covered in snow - so bad was the powdery mildew. Oregon Giant was good. OSP I grew a couple of years ago before I developed OCD about parchment. Will grow it again in Autumn. Shiras was good young, but the pods developed tastes that weren't pleasant as the bushes aged, and had some parchment at full maturity. The pea seeds are huge - and I elected not to try them at maturity. I have to say the environment for these grow outs were in a poly tunnel, and this year temps at least up to 45 C regularly. However all plants were irrigated very well. The reason I say this is parchment formation has been linked to a heat shock protein. I wonder whether dry conditions over express this parchment genes. I'll have to dig out the paper and re read.
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Post by steve1 on Dec 2, 2015 4:25:46 GMT -5
Yes the constricted pod definitely indicates the presence of a recessive reduced parchment gene. However, some pods start out constricted then inflate as they mature - I have seen this with my line (diggers) Yakumo that has delayed but full parchment formation. Dry pods are definitive in my opinion as if there is going to be parchment formation even if it's delayed it has to be there at full maturity. I'm not sure the pod curling being definitive of both recessive genes being present, as I've had this in one cross where I know I only have one gene in the mix - though I'd have to check whether it was a few or all pods on the lines concerned. Joseph's grind to dust method has much merit and I found reference to the method in King's genetics 1974 Ch7 on Pisum by Blixt. It's worth noting PPvv genotypes can have variable amounts of "patchy" sclerenchyma - and can have thin but peelable endocarp. My guess is Shiras is this genotype, and also has delayed parchment formation. My take home is that you can taste when the pea is at edible stage and be fooled into thinking in some instances there is no parchment when in fact it is just delayed. By comparing tasting with dry pod characteristics helps you to be sure that at least you're on the right track. Take samples of all the constricted pods and grind them up to assess for the presence of both genes. Also worth noting that V and Le are linked. I'm pretty sure in my f2 tall/short I didn't get a two recessive no parchment gene line in the 50 I grew. Cheers Steve
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Post by steve1 on Dec 1, 2015 2:51:00 GMT -5
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Post by steve1 on Nov 30, 2015 15:31:17 GMT -5
Thanks Philagardener, this one was a F5 so pretty stable now. Fair to say being on the other side of the world (isolation) has it's advantages - particularly when it comes to less bugs and diseases. Thanks for the tip, but I have used the milk spray on F2 peas, but am keen not to have to go there as long as I grow squash... Big plants = lots of time. I found a free Hort Science Journal review article on Pumpkin and Squash genes (2005). If it's of interest I'll post the link.
Cheers Steve
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Post by steve1 on Nov 30, 2015 6:07:09 GMT -5
Love all the maximas, must admit I had little idea of the real diversity available. Here's my maxima, it's a cross between Turks Turban and Australian Butter. Flesh is like Australian Butter not at all like the stringy Turk's. It has golden juvenile fruit that ripen to apricot. However it has no powdery mildew resistance at all which caused a very short (still got a few) season last year. Anyone know of any varieties with PM resistance? dl.dropboxusercontent.com/u/94877168/TurkishButterJuv.jpgdl.dropboxusercontent.com/u/94877168/TurkishButter.jpgCheers Steve
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Post by steve1 on Nov 30, 2015 4:44:25 GMT -5
Some of the peas are definitely mangetout. Today I attempted manual cross pollinations: [[Earliest Shelling Pea X Austrian Winter Pea] X Red-Podded Peas] Trying to move the red-podded trait into a winter hardy dwarf shelling pea that flowers and fruits precociously. Or simply to get a red-podded shelling pea. The mothers have not been screened for winter hardiness. They are just descended from winter-hardy stock. Whenever I attempt cross pollination of peas, I'm amazed all over again at how young the flowers have to be to get them before the pollen has been released. I am choosing white flowered mothers because I will be able to tell if the cross was successful, because successful crosses will have colored flowers. Joseph Lofthouse, I know this is a bit old, but if you do a coloured flower x white flower cross you can use the anthocyanin ring on the leaf axil to assess cross success much earlier than flowering (maybe 8 nodes to be sure) as colour on the leaf axil is linked to flower colour. Tall x short of course works too. And yes, it amazes and annoys me as the weather warms how tiny the female flower has to be to effect crosses. Does anyone use quick and easy old mendelian trait of constricted vs inflated dry pod to confirm parchment presence?
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Post by steve1 on Nov 25, 2015 6:27:07 GMT -5
Or UDDD sources in Australia?
Cheers Steve
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Post by steve1 on Nov 25, 2015 6:07:02 GMT -5
raymondo No problem. Two genes influence flower numbers Chapter 7 by Blixt in Genetics 1974 (by King) - fn and fna. According to the JIC germplasm database the two dominant forms = 1 flower per node, 1 dominant/1 recessive = 2 flowers/node and double recessive = > 2 flowers/node. data.jic.ac.uk/cgi-bin/pgene/default.asp?ID=303That means I suppose for any single flowered F2 has a 2/3 chance of having double flowered offspring and if both genes are in the mix a 4/9 chance of recovering the >2 flowered version. I must start noting what the F1's are doing more. Single flowered F1 means you have both recessive genes in the cross. That's straightened some things out in my head. Cheers Steve
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Post by steve1 on Nov 24, 2015 6:14:29 GMT -5
Hi all, just an addition to this thread - I use tape to cover over crosses after the cross is performed. I found successful pod forming crosses were 44/47 last year although somewhat less this year with losses to extreme heat when summer arrived in September (35 degrees C outside and 45+ in the tunnel). However you do the cross, use the keel (if its there) and the the petals to cover the stigma. Tape keeps up the humidity. Only one note, you need to watch closely and when the pod is starting to form remove the tape and relabel. Other wise kinked pods and some seed loss will occur. I first read reference to this in Carol Deppes first book, so not my idea but I can vouch for it. Cheers Steve Pea taped after cross dl.dropboxusercontent.com/u/94877168/PeaCrossed.jpgPod forming: www.dropbox.com/s/xq25sz81n8c39oy/PodForming.JPG?dl=0Oops too long! www.dropbox.com/s/ghfdwn6fkvghdpl/BentPod.jpg?dl=0
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Post by steve1 on Nov 11, 2015 22:59:29 GMT -5
Has anyone found any references to delayed parchment formation? I've had a bit of a look and come up with nothing...
Cheers
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Post by steve1 on Nov 5, 2015 12:01:00 GMT -5
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Post by steve1 on Nov 4, 2015 23:15:03 GMT -5
For those interested Yakumo with peeled endocarp stained. My thought is PPVV. dl.dropboxusercontent.com/u/94877168/Yakumostained.jpgAnd interestingly I found some extra Shiras snows that were at mature seed stage tucked away on a bench - and they had some fiber too. None at all from my tests at the normal snow stage. More delayed parchment formation? I'm guessing that must be controlled by gene or genes unspecified. dl.dropboxusercontent.com/u/94877168/Shiras.jpgHave done a couple of test crosses - so will see what falls out in the F1. I tend to make notes in a notebook and transfer them to excel later. Sprinklers are the arch enemy of computers! Cheers
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Post by steve1 on Nov 4, 2015 5:51:09 GMT -5
raymondo - yes sorry, the one I have labelled Golden Sweet, is sourced from Diggers and was sold as Golden podded. The Sugar Snap is the intermediate version 1.5 meters tall and stringy. I made a post earlier today on the ppvv list thread suggesting that you can use these as testers and the F1 pods would give you parchment status. If you are using your own lines of these, check when you cross them together the F1 comes out as fully parchmented. It just confirms that you have one recessive parchment gene in each variety. And also thank you for continually adding links for the references. Time is short at the moment. templeton - yes the Golden podded/sweet staining is subtle. I'm hoping it'll be improved on dry pods, but it may not be. Like the Pur colour gene it appears parchment genes are variable in the amount of expression and also time to development. Using test crosses and analysing the F1 pods may actually be easier. Staining purple pods ends up in a sea of red, and if you are trying to pick that subtle stain - no hope. I'm guessing the Yellow Taxi snow line likely only has one recessive parchment gene, which as you can see with the Golden podded is well enough. That stained pod was 4 weeks old and at full maturity - very little parchment and not discernible to tasters I would say. Were there any fibreless purple snows? Has anyone fiddled with refractometers for analysing sugar content in peas?
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Post by steve1 on Nov 3, 2015 22:10:24 GMT -5
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Post by steve1 on Nov 3, 2015 20:06:54 GMT -5
templeton, I've been using Phloroglucinol/ethanol/conc HCL (weisner test for lignin) on my fresh pods so far. No good with anthocyanins though. Phenols mess up the stain. Working on that at the moment. Have also been looking at the pods under light, my thought is you can see the VV genotype as shading under light and in stained transverse section. Haven't done all the data analysis yet to see if it makes sense. Like the protocols, and will try the staining on dry pods in the next few days and report back. The fresh pods show presence of significant parchment well enough, but making a call on PPvv genotypes with green pods is much harder. I have several price hedley papers on the gp gene, but tended to use a modified protocol by Drew 'cloning characteristics of genes determining pod morphology in pea' for staining fresh. It's another ethesis free online @ Durham university. I'll link some pictures from staining if it's useful. Cheers
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