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Post by terracotta on May 23, 2012 11:46:36 GMT -5
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Post by terracotta on May 24, 2012 12:55:07 GMT -5
I will search until I find genetics that thrive with my unamended soil, cold nights, diseases, super high humidity, extremely short growing season until I reach a perennial habit.
So I plant as wide a genome as possible, and let it rearrange itself as much as possible, and save seeds from those plants that thrive in my garden with unique climate. I mutate my seeds because much of the drudgery of collecting a broad genetic diversity has already been done for me.
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Post by Joseph Lofthouse on May 25, 2012 12:17:40 GMT -5
Here's another tease. Photo taken 4 days after potting up. Fluorescent lighting on 24 hrs per day, which is also providing heat to about 80F.  From front to back they are 18 hours, 26 hours, and 36 hours of exposure to Oryzalin solution. From Left to Right are water, and Oryzalin solutions of 2 PPM, 10 PPM, and 50 PPM. There was so much precipitation in the 50 PPM batch that it seems like it exceeded the solubility of Oryzalin. Hmm... Pause to do some research... Sure enough, the solubility of Oryzalin is about 2.6 PPM in water. So why does the research literature typically report using ~10 PPM Oryzalin for these conversions? I guess that it provides a saturated solution, but to what end? I wonder if it's one of those typical science things? Someone did it that way 50 years ago and it worked so nobody ever did anything different after that.... |
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Post by terracotta on May 25, 2012 16:00:27 GMT -5
thanks for the updates it is really interesting. How do you plan on screening for tetraploids or chimeras? With the ozyzalin did you notice a difference in root thickness or browning? lots of browning roots in my research.
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Post by terracotta on May 26, 2012 17:12:54 GMT -5
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Post by Joseph Lofthouse on Jun 1, 2012 19:46:18 GMT -5
Now what?  ?  I had expected poor emergence, but the worst pot had 75% germination, and many of them are around 100%... So what do I do now? Separate them out and plant them? Plant the whole pot and see if something interesting shows up? Next time it's obvious that I'll put them into individual pots, but that doesn't help me with these over-planted pots. Some of the treated pots have plants in them that seem precocious. The 42 hour soak for the longest water only control seems too long... Poor/slow emergence. 32 hours total soak time was OK. |
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Post by keen101 (Biolumo / Andrew B.) on Jun 2, 2012 1:53:00 GMT -5
I say just plant them as they are. Perhaps thin them a bit if you want, but otherwise just let them grow on their own. Some of mine were fairly crowded last year, and many of them again this year, and although they are not as even half as crowded as yours most of them did fine.
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Post by terracotta on Jun 2, 2012 15:53:33 GMT -5
www.springerlink.com/content/y0880442w267h277/www.liliumbreeding.nl/oryzaline.pdfThis should help with selection in thinning out. save the ones exhibiting mature qualities at an unusually early age or you can be like me and stick them in a fridge for 7 hours and whatever survives is the tetraploids because they have greater cold tolerance so far had only 1 dead blacktail out of 7, 4 crimson sweet out of about 10 and 1 jubilee out of 2 .
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Post by Joseph Lofthouse on Jun 4, 2012 1:59:39 GMT -5
SummaryI have identified 30 watermelon plants that might be tetraploids. Treatment in Oryzalin solution for 26 hours gave a tentative diploid to tetraploid conversion rate of 40%. A simple method for future use would be to measure the largest leaf on the controls, and then select as possible tetraploids any treated plants with leaves larger than the largest control. MethodToday I got out my calipers and started measuring the width of the first true watermelon leaves... I made graphs, and calculated histograms, and standard deviations, etc... ObservationsSome plants came up and put out cotyledons, but haven't yet developed a true leaf. Most of the seedlings that were in the 36-hour soak haven't sent out a true leaf yet, including the controls. So between a 6-hour soak in water, and the 36-hour soak in conversion solution, 42-hours soaking was too much water for the poor watermelon seeds. I saved 4 plants out of the treated 36-hour plants that were bigger than the largest of the 36-hr control plants: 3 from the 10 ppm solution and 1 from the 50 ppm solution.
 The standard deviation for the controls on the 18-hour soak was 73%, but it was only 39% for the 26-hour soak... This implies to me that it would be easier to pick out faster growing (presumably tetraploid) plants from the 26-hour soak than from the 18-hour.
No matter how many different ways I looked at the data, I couldn't see any clear pattern emerging for Oryzalin concentration... (All the solutions were essentially saturated anyway, so I wouldn't expect it to make much difference.) I may use 2 ppm in the future. Excluding the 36-hour test, the germination rate of treated seedlings was about 70% to 80%. It was 90% for untreated seeds.
With the 18-hour soak, there were 7 plants (out of 48) that were more than 2 standard deviations larger than the average of the controls. In practical terms there were 7 plants among the treated seedlings that were larger than the largest control seedling.
With the 26-hour soak there were 19 plants (out of 48) that were more than 2 standard deviations larger than the average of the controls. And there were 14 plants that were more than 3 standard deviations larger. In practical terms, 16 plants were larger than the largest control. They averaged 31% larger diameter.  In the future, I intend to use ~24 hour soaking times (and the 6 hr pre-soak). Calculations will not be needed, I can simply set my calipers at the diameter of the largest leaf in the control and select any treated seedling with a larger diameter leaf as a possible tetraploid. I may use 2 ppm concentration since it seems as good as anything. What Next?I intend to thin out any plant that is smaller than the largest control, harden them off, plant them in an isolated bed, and allow them to open pollinate each other.
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Post by raymondo on Jun 4, 2012 5:48:30 GMT -5
Nice one Joseph. Looks like there's a very good chance of a few tetraploid watermelons, which is interesting in its own right.
Are you going to try a cross with the straight diploids too? You'd probably have to double the ploidy after the cross to regain fertility I guess. Just curious.
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Post by Joseph Lofthouse on Jun 4, 2012 11:49:18 GMT -5
Are you going to try a cross with the straight diploids too? You'd probably have to double the ploidy after the cross to regain fertility I guess. Just curious. I'm intending to try crossing [diploid X diploid], and [tetraploid X tetraploid], and also [tetraploid X diploid] in all possible combinations. (I don't care if i end up with a sterile plant as long as it produces a perennial watermelon with non-poisonous fruit.) Now that I figured out a conversion technique that seems acceptable, I'll try converting B. alba to a tetraploid as well. Here's some more photos: Controls on left vs possible tetraploids on right:  Another angle showing a difference in height as well as leaf diameter. Controls still on left:  And the tray as it looks after I thinned, keeping the largest controls and the treated plants that are larger than the biggest control. Left to right ==> water, 2ppm, 10ppm, 50ppm. Front to back ==> 18 hr, 26 hr, 36 hr.  Last night was one of those nights that I lay awake day-dreaming rather than sleeping. Seeing how different the controls grew amongst themselves, and how quickly some grew compared to how slowly others grew, it got me to thinking that perhaps I aught to pre-screen watermelon seedlings for fast growth. I have noticed that in the garden in the past: Here's photos of melons planted on the same day a few feet from each other. Slow growing melon:  Fast growing melon:  So I'm wondering if I aught to fill a plug tray with my garden soil, and plant up a bunch of watermelon seeds, and screen them for quick growth. I'm screening anyway, because slow growing melons don't produce fruit for me, but if I could do it before planting-out I might get a better quicker harvest and faster genetic adaptation to my garden. |
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Post by terracotta on Jun 4, 2012 14:15:19 GMT -5
thanks for the info Joseph.
beginners typically throw out the weakest or chlorotic seedlings and then complain how conversion never works. tetraplods typically take longer than diploids due to longer division time about 5 to 15 days.
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Post by Joseph Lofthouse on Jun 4, 2012 14:27:41 GMT -5
thanks for the info Joseph. beginners typically throw out the weakest or chlorotic seedlings and then complain how conversion never works. tetraplods typically take longer than diploids due to longer division time about 5 to 15 days. Oh well... I just threw out all of the weakest plants. Didn't have any chlorotic plants to thin out though: [24 hour per day lighting.] There were some plants with twisted cotyledons. I threw those out as well. |
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Post by Joseph Lofthouse on Jun 9, 2012 18:29:57 GMT -5
This morning I transplanted the speculatively tetraploid watermelons into the garden. Also transplanted the controls into a different location. They are now the largest watermelon seedlings in the garden, much further ahead than the direct seeded patches.
The treated plants are still much larger than the controls.
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Post by terracotta on Jun 20, 2012 16:17:50 GMT -5
how are you determining which are chimera? if you see differences in coloration or leaf hair is a good one.
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