Thanks for all the posts Gabe.
Dean W: Will keep you posted if ever I find a source of reliable basjoo seed!
Found this very interesting article on M. basjoo, "The truth about Musa basjoo" (2007) by the british Musa expert David Constantine on his very comprehensive website. I hope I don't infringe on his copyright by citing a part about seed and propagation. (The whole article can be found here:
The truth about Musa basjoo.
It is really very, very interesting.)
Musa basjoo has been in continuous cultivation in the UK and mainland Europe since its introduction in 1887 or 1888 and propagated vegetatively by separation of suckers derived from leaf-opposed lateral buds; the Musaceae do not have axillary buds. Nearly all the M. basjoo plants offered for sale today are micropropagated, a process that essentially accelerates natural suckering through exposure of shoots to synthetic cytokinin in vitro. In highlighting the supposed relationship between M. basjoo and M. itinerans, Turner et al (2002) follow Simmonds (1962) and comment that both have long, stoloniferous rhizomes. This statement cannot readily be reconciled with horticultural experience as can be seen, for example, by examining the several clumps of M. basjoo growing at RBG Kew; Musa basjoo is a relatively close suckering species. In contrast, M. itinerans is said to produce suckers 2m away from the parent stem (Cheesman 1949). Cheesman (1948c) commented that M. basjoo is shy suckering and this can be seen in old established plants such as at Overbecks Garden at Sharpitor, Devon that have only ever been subject to conventional propagation from suckers. On the other hand, M. basjoo produced from micropropagation tend to sucker profusely, a probable carryover effect of the synthetic cytokinin used in the micropropagation process.
Musa basjoo produces viable seed in Japan where the winter temperature is no lower than -3.5°C (Amano), and presumably also in China, but so far seed has not been reported on plants in cultivation in the UK. The absence of seed has confused some people but has a simple explanation. In a typical banana inflorescence, the basal flowers are functionally female and the apical flowers functionally male; emphasis is placed on function rather than structure since all Musa flowers have male and female elements. There are a few Musa species that have functionally hermaphrodite basal flowers but M. basjoo is not one of these. By the time male flowers are produced on a M. basjoo inflorescence, the females are no longer receptive. An isolated plant producing a single inflorescence will not therefore set seed. However, where two nearby plants or two stems on the same “mat” flower asynchronously so that the first to flower can pollinate the second, there is no reason why viable seed should not be produced. Although the temporal separation of female and male flowers is designed to ensure outcrossing there is no self-incompatibility mechanism in Musa. However, in the U.K. another limiting factor is that a long, warm autumn would be required to develop and ripen the fruit. This has so far precluded seed production even in otherwise favourable microclimates such as at Overbecks where there are several flowering clumps of M. basjoo. Recently, there have been reports of viable M. basjoo seed being produced in the U.S. (Wagner pers. com. 2003) and there must be large areas of that country with a climate suitable for production of seed.
Seed of more and more banana species is becoming available commercially but for some reason seed of M. basjoo has not so far been offered, or, at least, not under that name. Chinese seed offered by Carl Sandeman in 2000 as Musa wilsonii turned out to be M. basjoo but with very low viability and seed of that provenance has not been offered again. With the increased interest in the Musaceae as ornamentals it is presumably only a matter of time before M. basjoo seed from China, or Japan, becomes routinely available.
Because of the lack of seed and the fact that it has been vegetatively propagated for so long there has been little variation in the M. basjoo offered for sale in Europe. Most plants represent the Veitch clone, more or less unaltered since its introduction. It is possible that some clonal variation has occurred through sporting, to which bananas are especially liable, or the accumulation of systemic pathogens. Anecdotally there do appear to be “good” and “poor” strains of M. basjoo in cultivation, but this requires further investigation. It is also possible that there were other introductions of M. basjoo by nurseries such as Vanhoutte, Verschaffelt & Donckelaer who were active in importing plants from China and Japan in the latter part of the 19th century. Although there are no contemporary reports of such introductions in Revue de Horticulture Belge et Étrangere or Revue Horticole this also requires further investigation.
Wouldn't it be fun to get some more variation in basjoo by growing seed propagated plants? I think it would, especially for nana growers like me living in a cold climate where the variety of nanas for growing outdoors is limited. For gardeners living in the sub tropics and tropics, who can choose and pick between so many wonderfull varieties we can only dream about growing outdoors, it's another story.