Breeding with Lamarque

Apart from M. Tillier, I want to try breeding with Lamarque. It's another great indestructible around here. The one over the road climbing up an old seedling apple tree is smothered in flowers right now.

So, what "disease resistant" roses do I use to get shrub roses from a climber? Do I use Lamarque for pollen or doesn't size matter which way you fertilise?

Dave, how do "you" go about choosing what you might 'put' over it or 'under' it, is it going to be seed, or pollen, maybe both

I dunno. That's my question. I've never used a climber before.

Can we have a big ruffled smelling repeat yellow please

Dave(s), this is pretty much a question of dominance and inheritance than anything.

Climbing seems to be controlled, mostly, by a single gene. This gene is dominant to non-climbing. This means, if they have it on any of the possible 2-5 (or higher) sets of chromosomes then it will show it. What you are hoping is that 'Lamarque', being diploid, has only one copy of climbing and it is masking a copy of non-climbing which can be brought backout again with a judicious cross. There is only one way to test it! You have to test mate. If you took something like 'Bon Siliene' and put it over 'Lamarque' and you got shrub forms then you know that 'Lamarque' is carrying non-climbing and showing climbing. That means there is a 50:50 chance of getting shrubs with any shrub you put it with. You might then decide to try and dwarf it by putting it with smaller polys or the like. If you only get climbers you know that it does not carry non-climbing and you will need to breed the progeny back to the shrub parent, or some other shrub to bring out the non-climbing again knowing that the progeny possess one climbing gene and one non-climbing gene (one from each parent).

This highlights something I wish more breeders understood, that breeding is not a single generational thing. You need to plan these things and trial them and, like in a game of chess, plan your strategy several moves ahead. Luckily, with HMF, you can do virtual test crosses by looking at how other people's crosses have turned out doing a similar kind of thing.

Thanks Simon. So is it better to pollinate Lamarque - or vice versa? I'm so impatient ( and unscientific/irrational) I've never done a second generation cross

Dave, I was thinking about this more throughout the day and, you know me, forever the teacher I thought I'd seize an opportunity to demonstrate how one might use HMF to deduce certain types of information, of a genetic nature, to help devise a breeding plan using 'Lamarque' as an example. I hope you don't mind.

Firstly I'll start of with totally annecdotal information from my own experience with 'Lamarque'. It's a B to work with! It works well as a pollen parent but only so-so as a seed parent and many of the seedlings will be garbage and mildew-prone. I haven't yet worked out what to use it with yet so thinking about it more I thought I'd detail what it was that I do to begin thinking about this, after initial failures

What is my goal? 'Lamarque' is probably one of the toughest roses we have for Australian conditions. If I could instill even part of its health, but ideally all of it, into something not so rampant then I think we'd have something excellent. There are a few assumptions being made here. The first being that the health can be passed on in the first place. Climbers are, by nature, more vigorous than non-climbers and so may by their nature also be more healthy and when you reduce this vigour maybe you will also temper the other properties. Health is also not a single factor. It is inherited in a multitude of different ways.

Has it been used in the past? Enter HMF! If you haven't done so already register and log in to HMF and look up 'Lamarque'. There are many advantages to being a fully paid up member of HMF and it offers many services to breeders that amount to being able to see every rose breeder's record book and having access to a wealth of genetic information... to those willing to take the time to look.

Here's the first clue as to how 'Lamarque' will breed. It's parents are 'Blush Noisette' x ' Park's Yellow Tea-Scented China' (PYTSC). 'Blush Noisette' is a noisette/climber stated to grow to at least 2m. This figure could be significantly increased here in Australia. So what? It's a climber... this is where 'Lamarque' got its climbing gene from. Here's the good news; PYTSC is not a climber. It's a shrub and so does not have the climbing gene. Being dploid makes 'Lamarque' easier to profile because there are only two sets of genes. This means it got one climbing gene from BN and one non-climbing gene from PYTSC. This is good news because it means that crossed with any other non-climbing rose there is a 50:50 chance it will throw non-climbers.

Then, click on the lineage tab and check out whether there are any descendants. Doing that shows 'Lamarque' has 304 registered descendants spread over 12 generations. Look at the first generation, as this is where you are up to. This reveals that there are 12 different roses descended from 'Lamarque' in the first generation. This figure is not too many to browse through completely. So let's see what we find:

1. '08 3C 36D': This is a rose bred by Warren that is a cross between Baronne Edmond de Rothschild ® and Lamarque. The bush is said to low and non-climbing. Proof that 'Lamarque' can throw shrubs when crossed with shrubs.

2. Adèle Pavić : seedling of 'Lamarque' stated to be a climber.

3. Solfaterre: As in 2.

4. Chromatella: as in 2 and 3.

5. Cool as Ice: Another rose bred by Warren. Parentage the same as in 1. Shrub form.

6. Cora L. Barton: No information given. Seedling of 'Lamarque'

7. Di Castello: Banksiae 'lutea' x 'Lamarque'. Massive climber.

8. 'JMB-06-8384': Sheila's Perfume × Lamarque. short bush to 90cm tall.

9. La Jonquille: Assuming a climber from the references.

10. Le Pactole: Lamarque × Parks' Yellow Tea-scented China, shrub to 1.2m tall (I'd love to get this one for breeding. Don't think it's here though.

11. Madame Byrne: Seedlig of Lamarque. No information given

12. Mademoiselle Germaine Raud: Chamoïs (tea, Ducher, 1869) × Lamarque - no firther information given

So... it's pretty clear that 'Lamarque' is split for climbing/non-climbing and can throw both giants and more subdued shrubs. It is also clear from this that 'Lamarque' works both as a seed parent and a pollen parent. All the colours seem quite muted so I doubt if 'Lamarque' is capable of breeding very strong colours... a 'criticism' aimed many Noisette/Tea/China type roses.

If it was me, I would put it with a polyantha because most polys are diploid. 'Cecile Bruner' or 'Perle d'Or' come to mind. These also have strong ties to Chinas so large departures from the type will not be experienced. Dave, when my '10000 Lights' China rose gets big enough to take cuttings from I'll send you a plant of it. Its stronger colour might work well with it. You could put it with other modern roses that are tetraploid to make triploids and hope for fertile trips. Some of the modern Kordes shrubs and floribunda might be useful. If put with DAs, choose something fertile. Other Teas would work well. M. Tillier x 'Lamarque' would be a ripper but still a bit bigger than you want. You could even go mini x 'Lamarque'. So many options!!!

Been thinking about joining HMF now I must. Thanks for sharing all that info Simon! Gives me some good ideas. Much appreciated

Very interesting reading, thank you Simon, and I will continue to follow your and others experiments with fascination. I put my own sloth down to the suspicion that selective breeding, unless done in serious bulk, improves the chances of a rosie lottery win only a little.

Very interesting, will reference it in the future.

Thanks Simon I am becoming better at understanding plant genetics thanks to your many posts and highlighting sites to visit.

You're not wrong, Meryl! Don't the Big Guns start with about 500,000 seedlings?
But I thought Lamarque was an OP fluke?

Here's my 'feelings' on 'the big boys'. The only reason they need to breed so many is because they are breeding the same old crap over and over and its getting harder and harder to find something new and different for a public driven by novelty when you aren't ever adding anything new. Us ameteurs can follow whatever path we like however obscure and stand to make much larger gains with just a few hundred seedlings than the 'big boys' can make with 500,000. It's all relative.

Just interested to know. Would the big boys use Lamarque or Teas?

nope That would be something other than floribunda or HT

Simon, that may be changing for I visit a large nursery selling the usual HT's & Flor types with emphasis on PBR plants.

Around the back of one of their buildings (Possibly where I shouldn't have been) is an area set aside for the unusual. These were all deep colours on bushes about 1800mm high. I'd bet someone elses life they were all roses but must have a closer look this season and take a cutter with me.

We can only live in hope, Bruce