Search found 383 matches

by Larry Davis
Wed Jul 18, 2018 10:39 pm
Forum: Rose Hybridizers Association Forum
Topic: Self-Incompatibility
Replies: 24
Views: 1436

Re: Self-Incompatibility

Without knowing actual mechanisms of incompatability I can think of some simple reasons for the ploidy effect. Assume that immunity requires recognition of "other". Therefore it requires recognition of "self" and a way to prevent responding to self in a bad way. That is how it works in humans. Some ...
by Larry Davis
Tue Jul 10, 2018 6:37 pm
Forum: Rose Hybridizers Association Forum
Topic: Under-utilized species you feel might have merit
Replies: 62
Views: 3939

Re: Under-utilized species you feel might have merit

The postage is only 7. 50 or so for a small priority mail package. By winter these will not be all that big. A couple dozen easily fit inside. Pot them up, select the first to bloom, or one with fewest prickles, or best foliage or whatever. Blooms might take a couple years if they are like other spe...
by Larry Davis
Mon Jul 09, 2018 10:59 pm
Forum: Rose Hybridizers Association Forum
Topic: Under-utilized species you feel might have merit
Replies: 62
Views: 3939

Re: Under-utilized species you feel might have merit

About R. palustris. I have little personal experience with it, though for decades I grew a plant that I brought from western PA that was probably it. I dug it out of a hillside bog there. May still be out in my wilderness though this year's drought may have done it in. Never got enough seed to get g...
by Larry Davis
Fri Jul 06, 2018 9:22 pm
Forum: Rose Hybridizers Association Forum
Topic: Under-utilized species you feel might have merit
Replies: 62
Views: 3939

Re: Under-utilized species you feel might have merit

That is a really interesting hybrid. Why does it bloom now? Hugonis is really early blooming and I thought wichurana was only moderately late. Maybe I was fooled by Dr. van Fleet bloom time. Or i this a second flush?
by Larry Davis
Thu Jul 05, 2018 11:56 pm
Forum: Rose Hybridizers Association Forum
Topic: RRV in Rugosa
Replies: 1
Views: 271

Re: RRV in Rugosa

I have very few rugosas and not a lot of RRD, but last year I lost 8 or 10 plants of mixed kinds because I took a wait and see attitude in one area of the garden. For high value plants I try to cut it out at the base of canes and with some I have successfully saved them. This spring I saw RRD on Bel...
by Larry Davis
Tue Jul 03, 2018 6:03 pm
Forum: Rose Hybridizers Association Forum
Topic: Breeding plans for 2018
Replies: 38
Views: 3673

Re: Breeding plans for 2018

For mnemko: Well, 13-1 is intense yellow, so you'd have to use a strong red at the very least. OTOH Rainbow KO as pollen donor to Playboy and Feu Josef Looymans gave the darkest reds I've seen. I didn't catch from your original post that your were targeting only red. The range of potential parents l...
by Larry Davis
Sat Jun 30, 2018 9:50 pm
Forum: Rose Hybridizers Association Forum
Topic: Breeding plans for 2018
Replies: 38
Views: 3673

Re: Breeding plans for 2018

On 4 plants I found only 9 pieces without either a hip or a flower or bud. But we'll see how those 9 turn out.

Last fall I took cut flowers of 13-2 and stuck them into potting mix and they all grew. Some selections really root easily.
by Larry Davis
Sat Jun 30, 2018 8:03 pm
Forum: Rose Hybridizers Association Forum
Topic: Breeding plans for 2018
Replies: 38
Views: 3673

Re: Breeding plans for 2018

So here it is almost July 1 and I think I may have a plan. Our wretched cold spring with repeated frosts, followed by sudden heat led to some odd replanning. Or non-planning, and certainly some unplanning. Might I suggest to mnemko that my 13-1 is worth consideration. Here's why. It came out of a cr...
by Larry Davis
Fri Jun 22, 2018 10:37 pm
Forum: Rose Hybridizers Association Forum
Topic: Diploid vs Tetraploid - a crossroads
Replies: 15
Views: 1025

Re: Diploid vs Tetraploid - a crossroads

I think that you will have to live through he triploid stage. Looks like a diploid trait will be harder to move to tetraploids than the other way round. It ought to be easier to bring repeat blooming to diploids than to take rugose foliage to tetraploids. I did a quick google search on tetraploid in...
by Larry Davis
Mon Jun 18, 2018 8:16 pm
Forum: Rose Hybridizers Association Forum
Topic: temperature effect on bloom form
Replies: 17
Views: 922

Re: temperature effect on bloom form

Yes, of course. The developmental program switches the pathways on and off to give all sorts of patterns. Red stamens, filaments, stigmas and styles are all independent of the patterns in the petals like central blotch, central yellow eye with sharp changes ( like Golden Slippers to pink or to red o...
by Larry Davis
Mon Jun 18, 2018 6:58 pm
Forum: Rose Hybridizers Association Forum
Topic: Remontancy
Replies: 25
Views: 2425

Re: Remontancy

Unfortunately Doubloons isn't actually hardy below 0 F and it is one of the worst black-spotters around. Can't comment on Mr. Nash.

I'm still using a couple Doubloons offspring but most have expired naturally. Well over 100 of them.
by Larry Davis
Mon Jun 18, 2018 6:51 pm
Forum: Rose Hybridizers Association Forum
Topic: temperature effect on bloom form
Replies: 17
Views: 922

Re: temperature effect on bloom form

I meant mechanistically at the biochemical level, not for imagining things through thinking by analogy. For plant people to talk of rabbits was once considered hareasy. Just pull one out of a hat. We focused on sweet peas (see my paper on "Origin of the Punnett Square") not the buggers that eat them...
by Larry Davis
Sun Jun 17, 2018 8:13 pm
Forum: Rose Hybridizers Association Forum
Topic: -Rising-Star-Awardee-Christian-Bedard
Replies: 6
Views: 497

Re: -Rising-Star-Awardee-Christian-Bedard

Interesting stats on the Weeks operation. Notice only 6 seeds per pollination. High failure rate at hip formation? Or low fertility crosses? Recall that seeds =/= seedlings. With 25 % germ/emergence/transplant survival it might be 6 intros per year out of 60,000 transplantable seedlings. Some parent...
by Larry Davis
Sun Jun 17, 2018 7:50 pm
Forum: Rose Hybridizers Association Forum
Topic: temperature effect on bloom form
Replies: 17
Views: 922

Re: temperature effect on bloom form

These days its much easier to understand suppression as a dominant feature. I had thought of it as a gap in a pathway for many years but all we have to do now is to invoke RNAi. HR may suppress the anthocyanin genes coming from AC leaving only yellow at ordinary temps. Previously I had assumed it wa...
by Larry Davis
Thu Jun 14, 2018 7:57 pm
Forum: Rose Hybridizers Association Forum
Topic: temperature effect on bloom form
Replies: 17
Views: 922

Re: temperature effect on bloom form

Yes, I saw that color effect on late blooms in heat back around 1980-85. I wrote about it maybe in the old days paper Newsletter of that time, or possibly on this forum a decade or so ago.. That's why I assumed that the true parent was Austrian copper rather than Persian yellow. Now of course someon...
by Larry Davis
Tue Jun 12, 2018 8:55 am
Forum: Rose Hybridizers Association Forum
Topic: Diploid vs Tetraploid - a crossroads
Replies: 15
Views: 1025

Re: Diploid vs Tetraploid - a crossroads

To Plazbo. Yes you are correct. Tetraploids beget tets. So of course New Dawn x HT = tet. But if there had been reblooming dips, it would have given a lot of dips. It is my understanding that if one has a decent stable of dips and tets, one can make crosses to generate interesting trip offspring. An...
by Larry Davis
Mon Jun 11, 2018 8:46 pm
Forum: Rose Hybridizers Association Forum
Topic: Diploid vs Tetraploid - a crossroads
Replies: 15
Views: 1025

Re: Diploid vs Tetraploid - a crossroads

Sorry for the acronym if that's the proper word. I wrote a long article on it in the newsletter a few years ago. It stands for Flowering locus C in the model plant arabidopsis. In roses it has a different name I suppose, but the principle is the same. When normal it allows flowering only after a win...
by Larry Davis
Sun Jun 10, 2018 6:25 pm
Forum: Rose Hybridizers Association Forum
Topic: temperature effect on bloom form
Replies: 17
Views: 922

Re: temperature effect on bloom form

Interesting that there are so well-established examples of the temperature effect. The two last flowers of the season on Silver Moon were almost normal. They have two rows regular petals, about 5 rows of petaloids with one yellow edge, lots of stamens displayed in an orderly way. These flowers appea...
by Larry Davis
Sun Jun 10, 2018 6:15 pm
Forum: Rose Hybridizers Association Forum
Topic: Diploid vs Tetraploid - a crossroads
Replies: 15
Views: 1025

Re: Diploid vs Tetraploid - a crossroads

My best guess, thinking of some other species that have been recently advanced by intensive breeding is that tetraploids have certain features that are advantageous in rapid reproduction/propagation for retail trade. Daylilies, iris, napa cabbage(which may have hybrid vigor being an allotetraploid) ...
by Larry Davis
Sun Jun 03, 2018 11:01 pm
Forum: Rose Hybridizers Association Forum
Topic: temperature effect on bloom form
Replies: 17
Views: 922

temperature effect on bloom form

This year we had a very cold spring with moderate to hard frosts interspersed with warmer spells from late Feb until late April. It was a cold winter too and Silver Moon lost a significant fraction of its long canes. With the cold weather delay it bloomed about a week later than usual. The most stri...