Creating x Racindsia 'La Mano Magica'.
Cultivars (Physiological aspects)
|Publication:||Name: Journal of the Bromeliad Society Publisher: Bromeliad Society International Audience: Academic Format: Magazine/Journal Subject: Biological sciences Copyright: COPYRIGHT 2009 Bromeliad Society International ISSN: 0090-8738|
|Issue:||Date: May-June, 2009 Source Volume: 59 Source Issue: 3|
|Topic:||Computer Subject: Company growth|
|Geographic:||Geographic Scope: Japan Geographic Code: 9JAPA Japan|
Many years ago I fell in love with Tillandsia dyerianafor its truly beautiful inflorescence and it has remained my favorite bromeliad species. However, I wanted to make the green, black-spotted foliage on my T. dyeriana more attractive by hybridizing. So I first thought of crossing it with Racinaea crispa (formerly Tillandsia crispa), admired for its attractive, wavy, dark brown leaves. Although once classified in subgenus T. PseudoCatopsis, the flower structure of R. crispa looks close to Tillandsia sub-genus Phytarrhiza, where T. dyeriana is classified, with its short, stout style and conspicuous petal blades. Therefore to me a pairing of these two species seemed possible.
Here in Tokyo, under my growing conditions, both species bloom in February to April, our northern late Winter and Spring. I had built up mature stock numbers of the proposed parents. Starting my challenge in 1999, I tried cross-pollinating many flowers, using T. dyeriana as seed parent and R. crispa as pollen parent. I could not pollinate during the daytime due to my demanding clinic duties, so night after night I spent countless hours pollinating. The stigma of T. dyeriana is very fragile so I used surgical tools. Another difficulty is that the flower of R. crispa is so small that it is not easy to extract enough pollen. Despite my efforts all the matings failed that year.
I reported the negative results to my very good bromeliad friends Harry Luther and Pamela Koide who commented that it might be impossible to breed such a bi-generic hybrid. However my passion was too strong to just give up my goal. In early 2000 my enthusiasm saw me preparing as many parent plants as possible. My pollination skills were getting better and I crossed about 40 flowers.
A few weeks later I was delighted to see that several seed pods had started to develop. Then came the long wait of nearly 1 year for the seed pods to mature and ripen. In my greenhouse I tried some traditional seed-raising with 100% germination. However these slow-growing hybrid seedlings were very prone to die from damping off, algae and moss. At this point my other good bromeliad friend Atsushi Sato helped me. He was a university student doing research on sterilised cultures. So Atsushi agreed to put the precious seeds in sterilised culture and he taught me the basic method.
From my 3 seed pods possibly 1,000 seeds were sent to Atsushi. His first try was on 23rd. February, 2001. The sowings were staggered over several different times for risk management purposes. There was almost 100% germination after about 3 days on a modified weak Murashige & Skoog growing medium. The seedlings grew very fast on this gel-like growing mixture, uncharacteristic of most Tillandsioideae seedlings which grow very slowly under normal conditions. In a strong solution there are plenty of sugars, amino acids, nutrition etc. but one risks burning or even killing the seedlings. At 2 or 3cms. tall these seedlings, with no pests or diseases to contend with, started pupping strongly, even though no hormones were applied. As the seedlings grew they tended to stop producing offsets. Within several months thousands of seedlings and attached offsets were produced. Later on, Atsushi's culture boxes got contaminated with a fungus and he lost most of the stock. Only a few seedlings survived. However, Atsushi kept growing these survivors which in turn multiplied by pupping easily. Eventually all these plants were sent to me.
Before this disaster occurred, luckily I had moved 4 advanced seedlings to my clinic to keep a closer eye on them. As per Atsushi's methods I set up a sterile growing unit. The culture stand had 3 fluorescent 20 watt light tubes per shelf, positioned 25cms. above the culture boxes. These tubes produced blue/purple light suited to aquarium plant culture and were switched on 16 hours daily. Later I discovered normal fluorescent tubes for indoor plants worked just as well. Room temperature was regulated at 24 degree C. all the year round. It is important to keep a stable temperature to avoid contamination. I changed the medium in the culture boxes every 2 weeks for 6 months and then monthly, as recommended by my orchid sterilised culture textbook. At one stage I felt the modified M.&S. medium was still too strong, so I changed the dilution level and concentration of sugars. The growth rate seemed to increase.
To avoid introducing any bacterial microbes or fungal spores a super clean bench and surroundings were imperative for these constant transplants. I used a special chamber box (same as for tissue culture) and wearing plastic gloves sterilised everything with ethanol spray. My new bi-generic produced almost no roots and in these pathogen-free conditions regular transplanting was neither a setback nor stressful. Providing the solution touched at least some part of each seedling, such as a leaf tip, stem or root, the seedlings thrived. Later I observed with my other hybrid sowings by this method that sometimes late-germinating seedlings got crowded out and lifted up off the solution. These I repositioned upright and back touching the solution. To my surprise the batch of 4 grew an incredible 1mm every day in the beginning, then each started throwing 3 to 5 pups simultaneously. These tiny 5mm. pups were removed and transferred to other culture boxes, keeping each clone separate. Such a procedure is not risky and was repeated when these propagules had their own pups. This potentially-endless cycle soon produced hundreds, but after reaching 8-10cms. tall, growth slowed.
Oxygen, humidity and CO2 levels within these closed boxes may have been excessive or insufficient but did not present problems. Although it's unproven yet, some scientists theorise that under these tissue-culture-like conditions, the seedlings and offspring do not photosynthesise light energy (despite strong light) but rather just absorb water and nutrients through their foliage.
Only 8 months after seeding, I transferred most of the plants from the sterilised culture boxes to the "outside world" of my home greenhouse. They were potted and rooted normally into an epiphytic mix, hardened off and acclimatised very easily but the growth rate slowed down. Foliar feeding with Hyponex regular liquid type, diluted 1000 times, was applied monthly as a booster.
Then at the age of only 18 months the first mature rosette finally bloomed in August, 2002. Flower petals were lemon yellow and the inflorescence was a lovely pastel orange colour. The beautiful brown wavy leaves with many dark spots showed the best of both parents. Later I found that occasionally mature rosettes would flower in other seasons also outside the parents' blooming period.
I was so happy that at last my dream had come true. My chosen cultivar name of 'La Mano Magica ' is Spanish, meaning "Magic Hand". All clones appeared identical hence only one cultivar name was registered. This bi-generic looks like a mesic plant but under my conditions grows even better when mounted, pupping well after blooming. Racinaea crispa is a cool-loving forest epiphyte from Panama to Peru at 300-1800m. altitudes. Epiphytic Tillandsia dyeriana inhabits warm lowland Ecuadorian mangrove forest. X Racindsia 'La Mano Magica' is tough and adaptable to warm humid climates (or simulated conditions) near sea level.
This cultivar was my very first hybrid bred by me and since then many more crosses are following, including other bi-generics using my beloved T. dyeriana. My unorthodox methods of cross-pollination and combined seed-raising/tissue culture had some major complications along the way but they fast-tracked the successful end results.
Many thanks to Atsushi Sato for his help in raising my hybrid and to Geoff Lawn for manuscript advice and goodwill support.
Smith, L. B. and R. J. Downs (1977). Flora Neotropica Monograph No. 14, Part 2: Tillandsioideae (Bromeliaceae). New York, Hafner Press.
Tomiyana, M. (1998). Clonal Propagation of Orchids. Tokyo, Tombow Publishing Co. Ltd.
Hiroyuki Takizawa M.D. and Ph.D. photos by the author.
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