An amphidiploid ... induced by colchicine

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An amphidiploid of Rosa banksiae and Rosa laevigata induced by colchicine.txt

The article describes the procedure used by Dr. Robert Basye to double the chromosomes of diploid roses.

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Dr. Basye made the interesting observation that “the more sterile the F1 cross, the more self-fertile will be the associated amphidiploid”. Wide crosses that result in sterile offspring, such as his banksiae x laevigata, can therefore be rendered fertile by this technique. It has potential utility also for making relatively sterile triploids into fertile hexaploids although this hasn’t been documented yet that I know of.

I grow 86-3. It is difficult to get to cross with anything, but not impossible. I’ve raised several seedlings from it which have all failed, until this year. Cal Poly X 86-3 is a definite hybrid. Cal Poly does not generate climbers from selfs. This is a definite climber, with sharp, need like prickles and characteristic Banksiae mildew. The foliage shows the Banksiae influence in shape, also. I can only add three photos so I’ll post 86-3 in the next post. Should anyone be interested in cuttings of 86-3, please let me know. As I said, it’s difficult to get to cross, but not impossible.

Cal Poly X 86-3

This is 86-3. Completely healthy in my climate, flowering early and as long “spring-like” weather remains.
86-3 (1).JPG
86-3 (1).JPG

Kim the last three shots are outstanding, what influenced the foliage, I love the flower.

Thank you David. This is a cross of Banksiae and Laevigata, the cross which reportedly created Fortuniana. The foliage IS outstanding and it is very vigorous. In this climate, the characteristic mildew in the seedlings is a good indicator of hybridity. It’s a lovely plant. I look forward to being able to plant it out and let it eat the world. I just observed the double white, double yellow, single yellow, VI Fortuniana and Purezza for leaflet count. Laevigata traditionally produces three leaflets. Both the double forms of Banksiae are producing three, four and five leaflets all over the plants. Purezza is producing five. Lutescens (single yellow) is producing four and five. 86-3 is producing four and five leaflets, no three leaflet growth. VI Fortuniana is producing three, four and five leaflets. Cal Poly X 86-3 is producing five leaflets.
According to Dr. Manners of Florida Southern University, Dr. Basye insisted upon using his virused Fortuniana root stock for all of his plants. Malcolm has said he offered multiple times to treat the stock for RMV, which is one of his functions during his tenure there at FSU, but Dr. Basye wasn’t interested. So, there is a very good chance that any (or all) of Dr. Basye’s roses are infected with at least RMV.