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At times I wonder if the explants in tissue culture are doing anything at all. One way I use to tell if an explant is making any progress is by using time lapse photography, which is what the above video is about.
The vessel was placed in my video box with the camera set to take a photo every five minutes. After several days the photos were compiled into video to determine what, if any, progress the explant has made.
This one is unusual, in so far as the "arms" droop, then callus begins to form at the shoulders and then the top. There is also new growth forming on the callus on the top of the stem.
These may be the last olives I place in culture, as my last batch of conventional cuttings have been a total success. Six out of six cuttings have rooted, and, they are from six different varieties.
Tissue culture will be used going forward for starting difficult seeds and for more difficult or exotic plants.
For olives I intend to use the method described in my last post, as I am not looking to produce thousands of plants, just one of each variety, which I have now begun to accomplish.
Since I switched to the new media for the olive trees there has been a spurt of new growth on all of the trees; that said, it is not unusual for olives to put out new growth at the end of summer. And, in the greenhouse, conditions are still summer like.
With all of the new growth I thought I would give traditional cloning another try, except this time I have made some major changes.
Instead of using sterile media, like coir and perlite, I used the same media that I am using for the mature trees. Six semi-hardwood cuttings were taken, with the bottom leaves removed, leaving about six leaves and in some cases the growing tip. Half of the remaining leaf sections were cut off to reduce moisture loss but still allow the plant to collect light.
Using a sterile scalpel I cut a one inch wound into the bark at the very bottom of the cutting just above the node. The cuttings were sprayed with anti-wilt and dipped into Vita Grow rooting hormone for thirty sections before being placed into the media.
The top was cut from a clear plastic bottle to form a dome for the plant. Several small holes were drilled in the bottle for ventilation and several vertical cuts at the base of the bottle allow it to compress to fit the container.
After watering the cutting the insides of the container were sprayed with water to increase humidity; when condensation is not visible on the inside of the plastic it it time to spray again.
The cuttings are receiving sixteen hours of light per day and have been in process for exactly one month. To date, not a single leaf has fallen or discolored, and, it has been only necessary to water the cuttings a few times.
On the first of November it will be 45 days since the cuttings were taken, I expect to see new growth begin soon thereafter.
Of all of my previous attempts at rooting olive cuttings without a misting system this approach appears to be the most promising.
One nice aspect of doing it this way, is that there will be no need to transplant the cuttings when they root, they can be grown on in the containers they were started in.
My post of August 7, 2014 concerned an attempt to micro-propagate single node cuttings from a Chemlali olive tree. It was my intention to use protocols with slightly different components and compare the results.
The Chemlali was part of an order of four varieties that I had recently received from a grower in Florida. All of the trees were covered in a film of debris that looked like it may have been fine dust that had gotten wet and dried on the plants. That said, I cleaned the trees as best I could before I took the cuttings, sterilized and placed them in vitro.
To my dismay, all of the explants developed contamination within a few days. Several attempts to rescue the cuttings failed, except for one.
Another trial was started today with a different variety, Empeltre, that came from the same grower in the same shipment. However, I am taking a different approach in processing the cuttings prior to placing them in vitro.
As you can see by the photo of the cutting above, this plant also has a film on the leaves that has resisted cleaning.
The leaves were first wiped using a Q-tip with water and a mild detergent, then processed in an ultrasonic cleaner. Using 500 ml of water, 25 ml of H2O2 and 2 drops of Dawn detergent to act as a surfactant, I processed the cutting for eight minutes at the unit's highest setting.
The liquid and cutting were then transferred to a Mason jar with a screen top and processed normally for one hour.
After rinsing in sterile water the cutting was cut into single node sections, which were then placed in vitro.
It should be interesting to see if the ultrasonic unit makes any difference in the outcome.
Last, but not least, the Bougainvillea seed shown in the time lapse video is making progress. Although the upper portion of the plantlet is growing very slowly, the tap root is an altogether different matter. It is the most unusual looking root system I have seen to date. The two dark circles resemble eyes, giving the root a most sinister appearance.
This week I received three more trees: Kalamata, Sevellano and Boutillian. Finally, at long last, my Olive Arborium is complete.
The trees are being fed on a regular schedule and the results have been fantastic. Trees that have recently arrived from nurseries, as well as all of the other trees, have added thick new growth.
I would like to have them in the best possible condition to cope with the long winter ahead, so hopefully next spring they will produce some fruit.
While visiting a plant nursery in Vermont late in July I came across a Bouganvillea plant. The plant was beautiful, but rather expensive, so I thought why not grow one from seed and place it in the greenhouse with the olives.
Finding Bouganvillea seeds turned out to be a challenge, but I finally managed to purchase some seeds for a plant with garnet colored flowers.
Some seeds were placed on moist paper towels to germinate and some were placed in vitro. I finally gave up on the seeds in paper towels after a few weeks. The seeds in vitro began swelling and produced radicles within about two weeks. Then, they seemed to grind to a halt.
Knowing that the seeds "need to see light" to germinate, I decided to give one vessel light 24/7 for several days to see what the effect would be.
The above video is a record of the experiment and this seed is far ahead of seeds started on the same day.
About this time of year I start thinking about providing supplemental light for the olive trees, which are more or less tropical.
This year I have taken a different approach, in that the lights are not on a timer, but are being turned on and off remotely.
As the temperature cools, our mornings tend to be cloudy, with little sun until just before noon. The lights are turned when I arise and they are turned off when the sun appears. If the day is completely cloudy, or rainy, I leave them on all day. If it was clear, I turn them on again for a few hours before civil sunset locally.
The lights in the photo may appear to be heavy on electrical consumption, however, as they are all LED grow lights, the total wattage is probably around 100 watts. In essence, the cost to operate the lights is really pennies a day.
The new soil mix has been a blessing, as the plants are responding nicely with new growth, and, they require much much less maintenance than the coir and perlite mix. If a stretch of nice weather is forecast, I move several of the trees outdoors and let Mother Nature care for them.
The Chemlali olive that arrived recently had a long lateral branch with developing nodes that were ideal for micro-propagation. I cut an eight inch length from the branch, which yielded five single node sections that were surface sterilized with bleach and alcohol prior to being placed in vitro.
For sometime I have wanted to try to tweak the olive protocol, so this should allow me to do so. The protocol in each vessel is slightly different in composition; in terms of more nutrients, or the addition of rooting hormones. The second vessel from the left contains woody plant media, which I have intended to try, but never quite got around to it.
Today I moved the olives back into the greenhouse from the deck, as we have had two major thunder storms this week that unloaded quite a lot of rain on the plants. The soil in the containers drains well, and I have drilled holes in the bottom of each container to allow excess water to flow through, however, I was just not comfortable with the plants being so wet. I tried to rationalize that several of the plants came from Florida, where it rains pretty much every day in some areas, but I was still not comfortable. As a test I am leaving two small olive plants on the deck to see if they survive all summer long with no intervention.
The weird looking plant above is a Drosera sessilifolia grown in vitro. It started from a single seed planted about five months ago. This plant should be flat, like a pizza, and consist of a single layer of traps; instead it is layer upon layer of traps, which are now beginning to flower.
It makes me think of the old margarine commercial that stated:"It's not nice to fool Mother Nature."
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