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Author Topic: California Super Mango rootstock experiment  (Read 7195 times)

Brev Grower

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Re: California Super Mango rootstock experiment
« Reply #50 on: March 15, 2018, 11:54:23 AM »
Ok, so I have been following along with this interesting experiment and from my understanding from the above articles, it seems that the only place there is genetic diversity is from material (shoots) arising from the graft union? Not from anything above it. Am I understanding this right?
E.

simon_grow

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Re: California Super Mango rootstock experiment
« Reply #51 on: March 15, 2018, 12:01:15 PM »
Behl, that could be one of the factors affecting the growth. We have noticed that vigorous varieties such as Valencia Pride, Lemon Zest, Sweet Tart and several others seem to grow more vigorously here in SoCal but the droopy growth habit remains on many of these varieties.

The Florida Turpentine rootstocks can grow ok as Frank mentioned, if you take special care to ensure the pH of the soil is slightly acidic but this is hard to do in many parts of SoCal where soil pH is generally above 7. With a pH this high, many of the micronutrients are locked and require pH lowering amendments or a heavy layer of mulch which encourages microbial life. The waste, excrement, byproducts, exudates of the microbial life affect the Cation exchange capacity and Anion exchange capacity which allows the trees to uptake more nutrients from the soil.

If one were to utilize soil, water, leaf samples such as what would occur on a large scale agricultural setting, there would probably not be any issues using Florida rootstock. There are tensionometers that can be utilized to tell you when and how much to water and many other technologies that can be utilized to succeed with growing Mango here in SoCal but Iím more focused on helping the average backyard hobbyist gardener succeed with growing Mango here.

The cost and complexity in regards to the above mentioned techniques is enough to scare new would be Mango growers away from this hobby and I have been bringing up the potential issues regarding Florida rootstock trees ( when grown in SoCal) so that others can avoid all the problems that may arise from selecting the less than ideal rootstock.

So far from my observations and back yard experiments, Mango seedlings are the best way to grow Mango trees. Mango seedlings grow with vigor, are much less droopy, do not have issues with pre mature lignification of thin branches and will not be stunted from flowering because they are not grafted with mature scion wood.

Simon

simon_grow

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Re: California Super Mango rootstock experiment
« Reply #52 on: March 15, 2018, 12:26:04 PM »
Ok, so I have been following along with this interesting experiment and from my understanding from the above articles, it seems that the only place there is genetic diversity is from material (shoots) arising from the graft union? Not from anything above it. Am I understanding this right?
E.

Brev grower,

Iím not sure I understand your question. If you are referring to a grafted tree, there is no genetic diversity because the tree is grafted, usually with a named cultivar. When someone talks about genetic diversity, they are usually talking about sexual reproduction.

In grafted trees, there may be horizontal gene transfer between the rootstock and scion but that is beyond the scope of what I want to discuss in this thread.

For my California Super Mango rootstock experiments, I am trying to find rootstocks that are very different in the hopes that one rootstock will outperform the other. The two easily distinguishable rootstock out there are Monoembryonic and Polyembryonic varieties. These are two huge bins we are categorizing Mangos into. Each of these bins will have cultivars that are better or worse adapted to specific growing conditions and disease pressures.

Sweet Tart and Lemon Zest are both categorized into the Polyembryonic bin but since Lemon Zest has horrible issues with Powdery Mildew, I would use Sweet Tart over Lemon Zest as the Polyembryonic seedling in my multiple rootstock experiments.

I would do the same thing with Monoembryonic seedlings but because there is a re arrangements of chromosomes in Monoembryonic seedlings due to sexual reproduction, each seedling needs to be treated as a unique individual. For example, you can plant 100 Kent seedlings and all 100 seedlings can have completely different growth habits, resistance to disease and productivity. All 100 seedlings will share the Maternal portion of its genome but the rearrangement of the chromosomes can turn on/off spicific genes or metabolic pathways which can affect all aspects of the resultant seedling.

Simon

Brev Grower

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Re: California Super Mango rootstock experiment
« Reply #53 on: March 15, 2018, 12:54:17 PM »
Hey Simon, I was referring to the horizontal gene transfer which the plants seem to be undergoing when they are inarched together as with your double rootstock experiments. One of the articles I was reading made it sound like the horizontal gene transfer ( or mixing of genes to produce a new species) was possible when grafting the two rootstocks together. But I was trying to make sure I was understanding the article correctly in my interpretation. It seems they were saying that gene mixing, asexually, is possible from the graft site of two species inarched together. So, on your DSG mango with one rootstock cut off, would the resulting material above the graft site have chromosomes from both rootstocks or just one? That goes back to my question about whether shoots coming from only the graft site are genetically mixed ( horizontal gene transfer) or if anything above the graft is then genetically manipulated. Again, I am very novice and my interpretation may be totally wrong. Just wondering as this may have implications in the future for mango hybridization, like your experiments...:) Thanks!
E.

simon_grow

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Re: California Super Mango rootstock experiment
« Reply #54 on: March 15, 2018, 04:01:11 PM »
Hey Brev grower,

The articles that I read explained that there is horizontal gene transfer from the graft sites but I donít know of the implications. I donít know that any of the transferred genes will cause any type of changes in the phenotype of the plant or fruit. This is beyond my knowledge level and Dr Ledesma, Dr Campbell or Dr Crane would probably have more info if you asked them.

Simon

RollingInTheWeeds

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Re: California Super Mango rootstock experiment
« Reply #55 on: April 25, 2018, 02:13:05 PM »
Hey Simon, I was referring to the horizontal gene transfer which the plants seem to be undergoing when they are inarched together as with your double rootstock experiments. One of the articles I was reading made it sound like the horizontal gene transfer ( or mixing of genes to produce a new species) was possible when grafting the two rootstocks together. But I was trying to make sure I was understanding the article correctly in my interpretation. It seems they were saying that gene mixing, asexually, is possible from the graft site of two species inarched together. So, on your DSG mango with one rootstock cut off, would the resulting material above the graft site have chromosomes from both rootstocks or just one? That goes back to my question about whether shoots coming from only the graft site are genetically mixed ( horizontal gene transfer) or if anything above the graft is then genetically manipulated. Again, I am very novice and my interpretation may be totally wrong. Just wondering as this may have implications in the future for mango hybridization, like your experiments...:) Thanks!
E.

Hi Brev Grower,
I got confused at the same point.  Without reading the complete original study to see exactly what the scientists did, it's a little unclear; I suspect that what's being hinted at in the summary Simon provided a link to is this: they took small samples of the tissue where the two plants were joined to one another, and (in a lab) cultivated that tissue into new "plantlets."  And those little lab babies had all the genes from both parents.  If that's the case, (and looking at the oak+beech picture at the top of the article as another hint), then the two stems/trunks stay genetically independent.

Simon, in your pictures it looks like where you join two stems one of those two ends up taking over from that point upward, and you snip off the weaker one after a while.  Is that correct?

simon_grow

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Re: California Super Mango rootstock experiment
« Reply #56 on: April 25, 2018, 06:53:45 PM »
When I innarch the seedlings together, I snip off the top of the seedling that I donít want after the graft has healed over. The remaining seedling with multiple rootstocks will grow over the left over stump leaving a smooth transition.

Simon

RollingInTheWeeds

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Re: California Super Mango rootstock experiment
« Reply #57 on: April 26, 2018, 10:45:52 PM »
You have a wonderful idea here, Simon.  Thank you so much for sharing it -- the ideas, the pictures, the lessons learned ... all of it.  It's a wealth of information that many of us can benefit from and then share our own evidence and lessons learned.  20 years from now there'll be backyard growers thanking you and others who contribute to the project.  (Of course a lot of us will be dead by then, but that's kind of the way it works, isn't it?)

simon_grow

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Re: California Super Mango rootstock experiment
« Reply #58 on: April 27, 2018, 12:33:00 AM »
Thanks RollingInTheWeeds,

I just hope that the people that really love Mangos and are passionate about growing their own fruit will be able to do so. The California Super Mango Rootstock trees are just for fun and so far they are growing great but for the majority of people in SoCal and elsewhere that live in marginal climates for growing Mango, I recommend they simply plant Polyembryonic seeds from good varieties for best success without the need for grafting.

Direct seeded plants donít have as many issues with over/underwatering that Potted seedlings have and you also avoid the need to transplant the seedling and acclimate it to full sun. The undisturbed taproot on direct seeded Mango trees also seems to help them survive adverse conditions better.

The CSMR plants are growing much faster than my single rootstock plants but Iím running into issues caused by me by not fertilizing adequately and not up potting in a timely manner. I can only imagine how fast they would be growing if I treated them properly.

Simon

 

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