Tetraploid Poncirus drought and cold resistance

[hardyvermont]

"accumulating evidence demonstrate that autotetraploids exhibit
dramatically enhanced tolerance to a variety of abiotic stresses, including cold, drought, salt, heat, chromium toxicity, and boron excess"

https://onlinelibrary.wiley.com/doi/epdf/10.1111/pbi.13064

Higher amounts of sugar in tetraploid plants may add cold tolerance?

[Ilya11]

An interesting article, thank you.
Not sure that their explanation of observed drought stress because of glucose accumulation is correct.
Sucrose levels are diminished, fructose was constant, overall sugar content weakly affected and strange inconsistencies in daily changes.
But certainly the drought resistance is there  and I believe it should correlate with frost hardiness. I know from experience that moderate drought is preparing plants for winter resistance, so these stress conditions are somehow connected.
Actually I have seen similar looking plants among poncirus seedlings, but they grow very slowly.
 

[Radoslav]

My lay view is, that thicker leafs help to overcome the drought, something like succulent plants do.

[SoCal2warm]

Citrus tetraploids typically display a little bit more cold tolerance and have slightly larger leaf and flower size.
However, they do not set quite as much fruit as normal diploids.

Tetraploid versions of diploid species are very common in the plant world, and with garden cultivars.
In fact, this is believed to be one of the possible routes of speciation, when a plant spontaneously doubles its number of chromosomes and then that leads to a reproductive barrier with the rest of the species gene pool (because the mixed offspring between the two groups, triploids, typically have marked decrease in fertility). There's even one example of this among citrus, the Hong Kong kumquat.