“Many years ago I fell in love with Tillandsia dyeriana for its truly beautiful inflores-
cence 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. Pseudo-Catopsis,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
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 universiry 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 srrong, 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
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