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Reading Templeton's blog
http://templetonsmedelania.blogspot.co.uk/ (entry of 2 June 2015)
about the 'n' gene in peas, informs us that this gene is pleiotropic - which means that it has further effects than just thickening the pod wall of a pea - it changes a mangetout into a snap pea, but that change comes with other changes that cannot be separated from the change to thick pod walls.
.
There is literature quoted on the JIC Pgenes pages
http://data.jic.ac.uk/cgi-bin/pgene/Default.asp?ID=484
and I read this article:
http://cuke.hort.ncsu.edu/cucurbit/w...les/art001.pdf
The conclusion about all the changes are summarised here:
Conclusions
"The major effect of the n gene when homozygous recessive was to produce plants with curved pea pods, round in transverse section, having thick pod walls. The nn plants also had pods with less length, width, area, volume, and weight than pods of N_ plants."
Recommendation for pea breeders:
"…… breeders ……. may profit by selecting for both thick pod walls and greater pod weight."
Several conclusions for my own breeding:
Bang goes the idea of breeding a massively large snap pea
The curve, which is so attractive in Charlie's Goldsnap, is not a fluke, but part and parcel of the 'n' gene. The supplementary question that arises out of this is, why are Sugarsnap peas not particularly curved? And why are Opal Creek, which were bred from Sugar Snap, sometimes curved and sometimes more straight. Sugar Magnolia is straight, and my Sugar Beth snaps are all straight.
http://www.growingfoodsavingseeds.co...creek-snap-pea
(2. 7. 2015)
http://www.growingfoodsavingseeds.co...gar-beth-snaps
Lastly, the advice to breeders is for selection. I am pondering this though - rather than only selecting after a cross, how about selecting for the largest parent varieties and start off with those? I don't have much data yet, but do believe that Charlie's Goldensnap might be larger than Opal Creek and that would be due to CEG being larger than Goldensweet (the other parent for Opal Creek). I need to keep an eye on size in future generations and select for this.
http://templetonsmedelania.blogspot.co.uk/ (entry of 2 June 2015)
about the 'n' gene in peas, informs us that this gene is pleiotropic - which means that it has further effects than just thickening the pod wall of a pea - it changes a mangetout into a snap pea, but that change comes with other changes that cannot be separated from the change to thick pod walls.
.
There is literature quoted on the JIC Pgenes pages
http://data.jic.ac.uk/cgi-bin/pgene/Default.asp?ID=484
and I read this article:
http://cuke.hort.ncsu.edu/cucurbit/w...les/art001.pdf
The conclusion about all the changes are summarised here:
Conclusions
"The major effect of the n gene when homozygous recessive was to produce plants with curved pea pods, round in transverse section, having thick pod walls. The nn plants also had pods with less length, width, area, volume, and weight than pods of N_ plants."
Recommendation for pea breeders:
"…… breeders ……. may profit by selecting for both thick pod walls and greater pod weight."
Several conclusions for my own breeding:
Bang goes the idea of breeding a massively large snap pea
The curve, which is so attractive in Charlie's Goldsnap, is not a fluke, but part and parcel of the 'n' gene. The supplementary question that arises out of this is, why are Sugarsnap peas not particularly curved? And why are Opal Creek, which were bred from Sugar Snap, sometimes curved and sometimes more straight. Sugar Magnolia is straight, and my Sugar Beth snaps are all straight.
http://www.growingfoodsavingseeds.co...creek-snap-pea
(2. 7. 2015)
http://www.growingfoodsavingseeds.co...gar-beth-snaps
Lastly, the advice to breeders is for selection. I am pondering this though - rather than only selecting after a cross, how about selecting for the largest parent varieties and start off with those? I don't have much data yet, but do believe that Charlie's Goldensnap might be larger than Opal Creek and that would be due to CEG being larger than Goldensweet (the other parent for Opal Creek). I need to keep an eye on size in future generations and select for this.
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