Breeding to maintain restore ancestral symbiosis

[pierre rutten]

Here is is a digest of recent thoughts of mine a non specialist.
Possibly not a first and not being omniscient here it is to critic and controverse.

Put in a few words that all need development.

Breeding for « better roots » sound obvious for any plant performance however difficult it is to evaluate.

More or less recent advances about soil ecology point to some strong consequences.
The development of roots is a major event in early plant evolution. First terrestrial plants had no roots and largely fed through cooperative organisms that coevoluted with plant diversification and specialization. For millenaries. And millenaries in every plant environment.

Hybridizing plants we select efficiently on above ground features reshaping them for obvious reasons or trying to.

At the same time we disrupt in ground adaptation symbiosis collaborations complementarities and other fragile equilibriums long evolved from life beginnings. Something whose replacement is at the cost of efficience. Instead of long proven collaboration it is the more opportunistic faster running collaborator/predator that is favored.

The first reason why « cultivated » plants ability to survive in the wild is so low.

In short term experimental environment there is no évidence as the more efficient slower symbiots do not have enough time or ability in situation that disfavor them to displace the virulent opportunistics.

This disruption we can avoid or lessen with a small change.
Between nuclear genes we work with and plant environment there is the cytoplasm whose inheritance is strongly to entirely maternal.

We should have the concern to maintain or restore as much as possible ancestral cytoplasms. Particularly with perennials.
Not difficult as very few backcrosses are enough to get genitors with an ancestral  cytoplasm just by keeping it on the maternal side of the crosses.

[Steph S]

Maternal DNA does sort of seem to have some noticeable effects in tomato lineage.
Of course it can be tested by growing out reciprocal crosses, with very divergent parents, but still without a means of actually separating the effects of Maternal from Nuclear DNA, it's not going to be super clear.
Hypothetically it makes sense, mtDNA and cpDNA are going to drive important metabolic trends.