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Post by stevestewart on May 13, 2007 22:24:31 GMT
Hello experts,
Do all the Petiolaris group of Drosera produce fertile hybrids, or does it depend on the plants used in the crosses? This sundew group seems to have been worked on extensively by a few dedicated growers willing to share their experiences. It would be good for novice growers to know.
I have some germinating and will be interested to see how they look.
Take care,
Steven Stewart
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Post by rsivertsen on May 14, 2007 2:17:33 GMT
To my knowledge, ALL Drosera hybrids are streile. There are few exceptions were one hybrid may undergo allopolypoloidy, where they double their chromosomes, and become fertile again.
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Post by Not a Number on May 14, 2007 5:08:38 GMT
According to Ivan Snyder:
"We were surprised when the cross between D. burmannii from Australia and D. sessilifolia from Brazil proved to be fertile. (We are constantly debating about whether they should be considered separate species.) Amongst South African sundews, D. dielsiana, D. nidiformis, and D. venusta can all be crossed and produce fertile hybrids. Most Drosera hybrids involving species with the same chromosome count are perfectly fertile."
Snyder, Ivan (2000) Colchicine Treatment on Sterile Hybrid sundews. Carniv. Pl. Newslett. 29(1):4-10
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Post by shartmeyer on May 14, 2007 13:52:00 GMT
Probably diverse plants of section Lasiocephala (Petiolaris, Lanata etc.) which have been grown in CP-collections from wild collected seeds should be relabeled, because cross pollination and fertile seeds appear frequently, and are therefore a more or less varying but certain part of "natural" seed portions.
Also the natural hybrid between D. spatulata and D. rotundifolia (in Japan) is so fertile, that it may behave like an invasive plant. Probably many of the D. spatulata "Kanto" species in private collections are actually that hybrid, as I learned at the ICPS conference Tokyo.
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Post by Not a Number on May 14, 2007 16:09:40 GMT
Yes and Drosera anglica, also fertile, is thought to be a hybrid of D. rotundifolia and D. linearis. Unusual because D. linearis has such a limited range.
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Post by stevestewart on May 14, 2007 17:51:09 GMT
Probably diverse plants of section Lasiocephala (Petiolaris, Lanata etc.) which have been grown in CP-collections from wild collected seeds should be relabeled, because cross pollination and fertile seeds appear frequently, and are therefore a more or less varying but certain part of "natural" seed portions. I will assume that the Australian cper's have compiled a comprehensive list of names to label the hybrid Petiolaris and Lanata plants that the rest of the world should adhere to. Or is that list still in the works? Thank you! Steven Stewart |
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Post by Khelljuhg on May 14, 2007 22:11:14 GMT
Also the natural hybrid between D. spatulata and D. rotundifolia (in Japan) is so fertile, that it may behave like an invasive plant. Probably many of the D. spatulata "Kanto" species in private collections are actually that hybrid, as I learned at the ICPS conference Tokyo. Well, I doubt if this is correct. The hybrids between Japanese D. spatulata and D. rotundifolia are usually sterile unless the chromosome number is doubled. The fertility of D. tokaiensis (which was derived from an F1 hybrid of this kind) is a result of allopolyploidisation. The name 'D. spatulata "Kanto"' does NOT refer to D. tokaiensis but a collective vernacular term for various D. spatulata forms found in Kanto area, Japan. D. tokaiensis was formerly called 'D. spatulata " Kansai"', NOT 'Kanto', because it is mainly found in Kansai area, Japan (By the way, this former name has been considered to be rather out-of-date here in Japan). |
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Post by RL7836 on May 14, 2007 23:04:57 GMT
To my knowledge, ALL Drosera hybrids are streile. There are few exceptions were one hybrid may undergo allopolypoloidy, where they double their chromosomes, and become fertile again. Hmmm - this is not my understanding of the plants in the Petiolaris group. I have heard / seen pics of a number of complex hybrids, similar to what we see w/ Sarracenia. (Am I misunderstanding the original poster's question?) |
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Post by ICPS-bob on May 14, 2007 23:38:07 GMT
Interesting, the ICPS database has this about the registered cultivars Drosera 'Kanto' and Drosera 'Kansai':
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Post by stevestewart on May 14, 2007 23:41:50 GMT
Thank you everyone, Hmmm - this is not my understanding of the plants in the Petiolaris group. I have heard / seen pics of a number of complex hybrids, similar to what we see w/ Sarracenia. (Am I misunderstanding the original poster's question?) No, you have understood my question and answered as I had understood this group to be, as the Sarracenia are (only producing 100's+ more seed per season per cross). This could make for some well thought out hybrids and cultivars if growers start to work together and compile data concerning individual hybrids. Because of the fertile disposition of Petiolaris hybrids, this group could already be difficult for certain paternal identification, just as easily. Take care, Steven Stewart |
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thwyman
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Post by thwyman on May 15, 2007 13:24:44 GMT
I will chime ina bit though RL has answered it pretty accurately. If you check the Lowrie list you will see pleanty of complex hybrids of petiolaris complex so these plants are definitly fertile
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Post by Dave Evans on May 16, 2007 2:46:07 GMT
North American (South American also?) species of Drosera all make sterile hybrids, like mules. Apparently, most species of Drosera do have incompatible genes on the compatible chromosomes (usually only closer relatives) in their DNA, and so the hybrids cannot make viable gametes. The majority of hybrids are naturally sterile. However, there appears to be no such barrier regarding the species in the petiolaris group, which can be interbred like Nepenthes. But can they be successfully crossed with any other species, not of the petiolaris group? I rather doubt it... I suspect the reason this group of plants produce fertile hybrids is because they are an important part of this group's evolution. Due to Australia's unique soil chemistry, for a plant species migrate, it also has to evolve to be able to deal with the soil in the new area. Hybridization can help speed the process of creating new combinations of characteristics. I suspect pygmy Drosera went through a similar stage in their evolution as well. To my knowledge, ALL Drosera hybrids are sterile. There are few exceptions were one hybrid may undergo allopolypoloidy, where they double their chromosomes, and become fertile again. |
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Post by Khelljuhg on May 16, 2007 17:23:53 GMT
Interesting, the ICPS database has this about the registered cultivars Drosera 'Kanto' and Drosera 'Kansai': I wonder why and how D. spatulata "Kanto, Japan" has passed as a registered cultivar (Or do I misunderstand anything?). In Japan, we do not define it as a cultivar (and I wonder how reliable those people such as Kondo or Shibata are). In any case, D. spatulata "Kanto" and former D. spatulata "Kansai" should not be confused (In the past, there was a checking station which devided the area, and the name 'Kansai' comes from 'the west of the area' and 'Kanto' means 'the eastern part'). Before 'D. spatulata "Kansai"' was separated as D. tokaiensis, Japanese CP growers called them in this manner ("Kansai" and "Kanto"), contrasting the plant features and the places. |
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Post by Dave Evans on May 17, 2007 4:07:05 GMT
Hello Khelljuhg,
This usage is actually a good example of a cultivar. Species in cultivation can be named as cultivated varieties before they are scientifically described. Part of the description would include information where they are naturally found. There are literally hundreds, if not thousand of cultivars collected directly from the wild.
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Post by Khelljuhg on May 17, 2007 18:22:17 GMT
Hello Dave,
Thanks for the answer. I do agree with you, but what I was trying to say is that I wonder why they have registered D. spatulata from Kanto area, Japan as a cultivar when it obviously includes multiple forms. The D. spatulata found in the area is not uniform but variable. Origianlly, the name is just a vernacular term, as I have noted above.
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