| By Jack Carpenter
After hearing so many different views on tissue culture through comments made by friends, I decided two years ago to conduct an experiment on tissue culture with a few seedlings of promise. When I first thought of doing the experiment it was with hopes of the experiment being successful and producing exact duplicates of the original seedling as well as speeding up release time. I had no idea that the procedure was to be as involved as it proved to be. Removing the tiny plants from agar gelatine was tedious and planting them was more so. Keeping them alive and preventing rot and damping off was also a laborious matter. It would have been impossible for me to handle any large numbers of plants this way with out special areas and facilities for doing so. Even so, some of the tiny plants were lost for one reason or another. The cost of doing the small number of plants also made the venture costly as compared to normal vegetative clump increase or use of hormones such as BAP-10. Another surprise was the length of time it took for the tiny plants to finally reach bloom size. All of the plants took a year and a half to bloom for the first time. This afforded me the first opportunity to see if the plants looked like the plants from which they came. Here are a few things that were notable in the plants through the first year of bloom: APPEARANCE: The appearance of flowers between the tcs and the originals was seemingly the same. The same variations that might be found in the originals was found in the new plants. VIGOR AND INCREASE: The vigor and increase of both the originals and the new plants seemed to be the same. I had thought there might be less increase in the tissue culture plants, but this did not prove to be true. SCAPE AND BUD COUNT: This particular characteristic showed the most variability. These plants were coming into bloom for the first time after at least a year and a half. At this point in time the plants were quite strong and vigorous and I expected to see no difference between the originals and the new plants. Consistently, however, there was notable difference in the originals and the new plants. The originals had better branching and bud count. The difference was about 2 to 1 or twice as many buds on the original plants as compared to the tissue culture plants. This really surprised me since doing so very few plants I thought should have provided no difference in this area. This part of the experiment is still on going and will not be finalized before bloom season completes this year when the tissue culture plants are on their second year of bloom. POLLEN/POD FERTILITY: Several plants were used for pollen and pods. In both cases the pollen proved fertile and pods set. Pod set was reluctant at first but later in the scape bloom cycle the pod set became easier as was the case with the originals. Pollen fertility seemed the same. EVERGREEN/DORMANCY: No variation was observed between foliage characteristics. ROOT STRUCTURE OR VIGOR: No variation was observed between roots and root vigor between the new plants and the originals. Well, the above information gives a preliminary idea of our experiment with tissue culture. Because the bud count and scape branching were less on the new plants as compared to the original on this past first year of bloom, it is necessary to carry the experiment thru this second year of bloom to determine if the difference is definite or rather circumstantial. The new updated data will be added at the end of this discussion at the end of bloom season 2002. The results of this year’s bloom season is still pending regarding the bud and branching question between new plants and originals, but, regardless of this outcome, it will not, for us, make tissue culture a feasible approach when releasing cultivars in smaller numbers such as most hybridizers do today. Why? Primarily, because it does not shorten the time of formal release of a cultivar. If you wait until the original seedling seems to show promise in its second year of bloom and at that time culture it, it takes another two or three years to prove the tissue culture plants. What does this mean? Simply that with good gardening culture you can increase a seedling sufficiently in three to four years to release it anyway. Many are getting increase from one to seven fans per year. If you increase it this way it is less time consuming and costly and should be true in all respects. If this experiment concludes as showing a definite difference between the bud count and branching, then that is also a negative against the tissue culture approach. Of course, if you have an outlet for hundreds of thousands of plants as through the major outlet stores, you would have to go the route of tissue culture. Unfortunately, such mass tissue culturing may cause a rapid drop in the price of new cultivars if said cultivar is placed in culture by a lab immediately. This may be good for the general consumer but is most unfair to the hybridizer who has worked years to come up with a worthy release. A hybridizer’s customers may not be anxious to purchase from him at initial introductory prices if they think the cultivar is going to be mass cultured numbering in hundreds of thousands. RESULTS OF BLOOM SEASON 2002 IN REGARD TO THE ABOVE: (look for the conclusion of our experiment on the above question this summer here in this location) CONCLUSION (2002 DATA) FOR With the second year of bloom for the tissue culture plants now behind us here at the Lily Farm, we observed an improvement with the one feature that had shown the greatest difference in our experiment last year. As indicated in the 2001 data above there was not any great amount of difference between the tc and original stock except in the area of branching and bud count. This 2002 season did reduce this difference by giving a little higher bud count and a little better branching in the tissue culture plants as compared to the year 2001 performance. In the year 2001 the tissue culture plants had about one half as many buds as the original stock plants. This year, 2002, the bud count was better with the tissue culture plants having about two thirds the bud count of the original stock plants. With only four different cultivars tested it is
doubtful as to how accurate or authoritative any conclusion could
be. It did, however, indicate to us that it takes longer than we had
thought it would to increase stock of a cultivar by means of tissue
culture. In our observations here the results indicated that bud count
and branching seemed to be the only difference. To what extent this
difference would obtain in a much larger sampling of tissue culture
cultivars is unknown. I would choose to go with original stock plants
if I had the choice based on this limited experiment. I rather doubt
that a third year will make any great difference between the tc plants
and the originals. Though each group was marked here in the garden the overall difference between the two groups was not easily noticed when you had forty plants of the tc and forty plants of the original growing side by side. Customers made comments on several occasions that they could see no difference. You could only see a difference when you made an analytical observation and you started counting buds and branching. It was amusing that after some customers counted the buds and saw the difference that they still chose the tissue culture plants because they had more fans than the original plant. In conclusion, then, everyone has to decide how
he or she feels about the question of tissue culture of daylilies.
I ended up preferring the original stock and that is what I recommend
to those who ask me, but not to the extent that I would reject a tissue
culture plant of a greatly desired cultivar if that was all that was
available or if the price was otherwise Sincerely, |