Search found 1242 matches

by Karl K
Mon Jun 11, 2012 10:52 pm
Forum: Rose Hybridizers Association Forum
Topic: The quest for Yellow
Replies: 89
Views: 4796

Re: The quest for Yellow

Is it just a matter of looking at it under a binocular microscope? Will x20 or 40 do? Simon, You would need at least x100 to see large plastids. x400 or more would be better. And be sure to compare matching regions of the petals of the different specimens. Tracking the inheritance of three independ...
by Karl K
Mon Jun 11, 2012 8:41 am
Forum: Rose Hybridizers Association Forum
Topic: The quest for Yellow
Replies: 89
Views: 4796

Re: The quest for Yellow

When breeding for yellow, it is useful to have a look at the plastids (or chromoplasts) that carry the yellow carotene pigment. These vary in size and number as well as in color. Two varieties may appear similar in color, to the naked eye, even though one has numerous small plastids while those of t...
by Karl K
Fri Jun 08, 2012 4:46 pm
Forum: Rose Hybridizers Association Forum
Topic: What's up with Rosa foetida?
Replies: 30
Views: 2800

Re: What's up with Rosa foetida?

The mystery deepens! I have been exchanging emails with Peter Harris, who has been collecting all the info he can find on 'Harison's Yellow' and the numerous imposters that travel under that name. There are quite a few. Many are probably OP seedlings of 'Harison's Yellow'. But 'Williams' Double Yell...
by Karl K
Thu Jun 07, 2012 3:35 pm
Forum: Rose Hybridizers Association Forum
Topic: Beginner question: lavender plus lavender = yellow???
Replies: 29
Views: 3074

Re: Beginner question: lavender plus lavender = yellow???

My comment on 'Marechal Niel' was mistaken. I do have an idea of what's happening. Apparently the carotene-cleaving enzyme is inactive at high temperatures. So, when MN is grown under glass, the color deepens. I'm guessing the fragrance declines. But in a more moderate climate, the color is a soft y...
by Karl K
Thu Jun 07, 2012 3:27 pm
Forum: Rose Hybridizers Association Forum
Topic: Pollen from a Hybrid Gallica?
Replies: 4
Views: 791

Re: Pollen from a Hybrid Gallica?

Oops! I got the country wrong as well as the other species. The note was sent 27 March 1996. Aila Korhonen in Finland was discussing a "found" rose that was thought to be Rosa gallica 'Grandiflora'. 'Alika' is supposed to be a selection from 'Grandiflora'. "The Institute of Botany in Helsinki Univer...
by Karl K
Thu Jun 07, 2012 1:27 pm
Forum: Rose Hybridizers Association Forum
Topic: Having snared an old moss, Flamingo ponders his next move.
Replies: 21
Views: 1002

Re: Having snared an old moss, a flamingo ponders his next m

Ralph Moore (1967) had a similar problem breeding with Crested Moss. He just waited until he found a flower with some anthers. "The crested moss type has been mentioned briefly but a bit more should be added here for clarity. There were no doubt other members of this type which were lost along the ...
by Karl K
Thu Jun 07, 2012 12:59 pm
Forum: Rose Hybridizers Association Forum
Topic: The quest for Yellow
Replies: 89
Views: 4796

Re: The quest for Yellow

If you want something smaller, you might try 'Sunshine' (George Elger × William Allen Richardson). It is more amber than yellow, and the color does fade. Still, it probably hasn't been overused in breeding. Sunshine Le Grice's 'Allgold' has a lot going for it. Hardy, bright yellow, disease resistan...
by Karl K
Thu Jun 07, 2012 12:34 pm
Forum: Rose Hybridizers Association Forum
Topic: Pollen from a Hybrid Gallica?
Replies: 4
Views: 791

Re: Pollen from a Hybrid Gallica?

If I remember correctly, back in the days of rec.gardens.roses someone reported that 'Alika' was bred in Sweden from R. spinosissima and R. gallica.

Karl
by Karl K
Thu Jun 07, 2012 10:40 am
Forum: Rose Hybridizers Association Forum
Topic: Using mixed pollen?
Replies: 23
Views: 1367

Re: Using mixed pollen?

David, Here are a few references for species in the Rosaceae: Yenikeyev: Pollination with a pollen mixture (1965) Hybridization of the blackthorn ( Prunus spinosa L.) with the domestic plum ( P. domestica L.) was also facilitated by using a pollen mixture of several plum varieties (cf. also YENIKEYE...
by Karl K
Wed Jun 06, 2012 11:04 am
Forum: Rose Hybridizers Association Forum
Topic: What's up with Rosa foetida?
Replies: 30
Views: 2800

Re: What's up with Rosa foetida?

Simon,

Thanks for checking. The book I had was Macoboy's "Ultimate Rose Book".

Karl
by Karl K
Wed Jun 06, 2012 11:03 am
Forum: Rose Hybridizers Association Forum
Topic: Beginner question: lavender plus lavender = yellow???
Replies: 29
Views: 3074

Re: Beginner question: lavender plus lavender = yellow???

The most potent fragrances in roses (the so-called Rose Ketones) are produced by the oxidative degradation of carotenes. Yellow roses are colored by carotenes produced in the plastids. A specific enzyme, if present, snips the carotene molecule into three fragments. When these are oxidized, they beco...
by Karl K
Wed Jun 06, 2012 10:33 am
Forum: Rose Hybridizers Association Forum
Topic: Using mixed pollen?
Replies: 23
Views: 1367

Re: Using mixed pollen?

Pierre, The mentor effect is important in some crosses. In addition, there is a maternal influence. The seed parent cannot choose to provide extra nutrition to seeds with a superior genotype, of course. But it can "play the odds" by investing more heavily (supplying more nutrients) to fruit that hav...
by Karl K
Wed Jun 06, 2012 10:19 am
Forum: Rose Hybridizers Association Forum
Topic: What's up with Rosa foetida?
Replies: 30
Views: 2800

Re: What's up with Rosa foetida?

Adam, I agree that Rosa foetida seems to be a mountain plant from a region with dry summers. The short-lived leaves are found in other plants inhabiting similar regions. There is a South American Amaryllis (Hippeastrum) that flowers and produces leaves that last only 3-4 months. Also, an Australian ...
by Karl K
Tue Jun 05, 2012 7:21 am
Forum: Rose Hybridizers Association Forum
Topic: What's up with Rosa foetida?
Replies: 30
Views: 2800

Re: What's up with Rosa foetida?

Adam, I once found hips on Rosa foetida bicolor at the Heritage Rose Garden (San Jose, CA). They were empty. Still, it's worth checking. There have been cases of plants that were nearly sterile when first introduced to a new region, but which managed a few seeds. Second and later generations became ...
by Karl K
Mon Jun 04, 2012 9:14 pm
Forum: Rose Hybridizers Association Forum
Topic: Using mixed pollen?
Replies: 23
Views: 1367

Re: Using mixed pollen?

Pollen mixtures can be useful when attempting to breed with a species. Instead of picking one specimen at random and hoping for the best, grab pollen from several plants. There is also evidence of a sort of "step father" effect. Only one pollen tube fuses with the ovum, of course, but other pollen t...
by Karl K
Mon Jun 04, 2012 9:06 pm
Forum: Rose Hybridizers Association Forum
Topic: What's up with Rosa foetida?
Replies: 30
Views: 2800

Re: What's up with Rosa foetida?

Simon, I came across your report while I was looking for more instances of fermentation and germination. Van Mons (1835) collected unripe pears and let them ferment before sowing the seeds. He made major improvements in pears, back in the day, and influenced rose breeders among others. When Van Mons...
by Karl K
Mon Jun 04, 2012 2:52 pm
Forum: Rose Hybridizers Association Forum
Topic: Using mixed pollen?
Replies: 23
Views: 1367

Re: Using mixed pollen?

There is evidence that mixed pollen germinates better than pollination by a single specimen. Some of the evidence is scientific (controlled studies), some is anecdotal. Cook: Hybridizing (1907) I have several [rose] seedlings, where the pollen was taken from three and four different varieties mixed ...
by Karl K
Mon Jun 04, 2012 2:19 pm
Forum: Rose Hybridizers Association Forum
Topic: 'Emily Gray'.. a triploid????
Replies: 5
Views: 542

Re: 'Emily Gray'.. a triploid????

SimonV, I found this item just yesterday that would explain the chromosome number: USDA Inventory of seeds and plants imported (May 1922) From Cheshunt, Hertford, England. Plants purchased from Paul & Sons. Received May 9, 1918. Quoted notes by Dr. Walter Van Fleet. 46079. ROSA sp. Rosaceae. Rose. "...
by Karl K
Mon Jun 04, 2012 2:03 pm
Forum: Rose Hybridizers Association Forum
Topic: What's up with Rosa foetida?
Replies: 30
Views: 2800

Re: What's up with Rosa foetida?

SimonV, I'm guessing that one reason Rosa foetida usually doesn't seed unless hand pollinated is that it blooms too early for the available pollinators. The low percentage of viable pollen doesn't help, either. 'Harison's Yellow' has frustrated some breeders. American Rose Annual 1: 34 (1916) Dr. W....
by Karl K
Mon Jun 04, 2012 9:25 am
Forum: Rose Hybridizers Association Forum
Topic: What's up with Rosa foetida?
Replies: 30
Views: 2800

Re: What's up with Rosa foetida?

I have read elsewhere that some writers suggest that Rosa foetida is a hybrid of R. kokanica. But is the latter species at all common? Since Rosa foetida is commonly cultivated in Iran today, it seems reasonable to suppose that it was also cultivated in the past. And if so, then the limited gene poo...