TB: HYB: PBF cross
- Subject: TB: HYB: PBF cross
- From: "Neil A Mogensen" n*@charter.net
- Date: Thu, 21 Nov 2002 05:58:50 -0500
As the seedlings grew larger it was possible to get a rough estimate on the PBF of reciprocal crosses between a seedling P 1-13:(Swingtown x Romantic Evening) which shows no PBF and HAPPENSTANCE, which has a weakly expressed PBF.
Of the seedlings (no exact counts--I'm not able to do that right now for medical reasons) more than a quarter and less than half of both crosses, one with HAPPENSTANCE as pod, the other as pollen parent show PBF to varying degrees, some definitely more strongly expressed than Happenstance.. There is no obvious difference in the ratio of PBF/non-PBF between the crosses, fairly strongly suggesting that the factor(s) are in the nucleus, not the cytoplasm. If there were a cytoplasmic factor or factors involved, the two crosses would have had distinctly different ratios.
The apparent ratios also suggest that there is more than one genetic factor involved. The same P 1-13 crossed with FOGBOUND (reciprocal crosses), neither expressing PBF, produced not a single PBF seedling in over a hundred seedlings, yet I believe Fogbound is the parent of PBF offspring in other crosses for Keppel.
This suggests that at least one of the primary factors for PBF is dominant. I suspect there are also modifying factors involved, perhaps including an inhibitor of the anthocyanin formation in the foliage. Also, the variation in the seedlings suggests intensity of expression of PBF is not due only to dosage effects, unless P 1-13 carries PBF masked by an inhibitor. PBF-expressed cultivars are present in its ancestry, I believe.
All this is strictly speculative, and I WILL make exact counts when weather conditions and my mobility allow, but that may not be until sometime next spring. I offer the observation simply for what it may or may not suggest for further investigation into the inheritance of PBF. The only thing that seemed certain to me is that the inheritance of the characteristic is not a matter of a simple, single factor.
Offered for what it's worth.
Neil Mogensen z 6b/7a between Asheville and Hendersonville, NC
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