One of the things I like about the horticultural field is its sharing of information.
I’m building a food forest, arboretum, and carbon-negative eco-tourist resort. I’ve started a tree breeding program.
I’m aiming to produce disease resistant trees, that also produce food and have valuable timber. It will take several decades. Well, there will be relatively instant income from trademarked wild cultivars (but trees coming back from population bottlenecks won’t be mass cloned by my business…) I aim to create exceptionally resilient trees and forests that exploit the oxalate carbonate pathway (yes, that requires non-limestone sources of calcium or, perhaps, magnesium.)
The most interesting thing about induced polyploidy is that it allows the creation of a natural vertical gene barrier for CRISPR! It should be incumbent upon those who perform genetic modification of seeds to first induce stable polyploid lineages, so that there will be at least one natural vertical gene barrier preventing vertical transgenetic gene transfers to wild plant populations.
On 6 acres that had been unmanaged for decades, I had at least 41 native naturally occurring tree species: southern sugar maple (Chalk maple, specifically), bois d’arc, red maple, loblolly pine, shortleaf pine, red mulberry, black cherry, sassafras, post oak, chinquapin oak, rusty blackhaw, gum bully, water oak, willow oak, black oak, blackjack oak, shumard oak, southern red oak, redbud, dogwood, winged elm, american elm, black willow, white ash, hackberry, cottonwood, American sycamore, persimmon, honey locust, American holly, red cedar, yaupon holly, sparkleberry, eastern swamp privet, texas hickory, mockernut hickory, pecan (or perhaps bitter pecan?), sweet gum, black gum, texas plum, hornbeam. Added: Cherrybark Oak, swamp chestnut oak, kentucky coffeetree, pecan, paw paw, black locust.
Additionally, I might also have Northern Red Oak, Texas Red Oak, or Nuttall’s Oak. I think I have two species of bayberry, definitely at least one. Red elm might also be on the property. I have at least two types of native grapes, as well as Vaccinium Pallidum.
On .91 acres in Hochatown, I have 9 species: red mulberry, black hickory, red cedar, winged elm, post oak, black gum, shortleaf pine, redbud, sparkleberry, texas plum, I added pecan, Ouachita witch-hazel, persimmon, paw paw, and honey locust. (And Ouachita Hawthorn is just a few feet away!)
There’s so much interesting information about all of these tree species. The paw paw is the largest edible fruit* native to North America and can produce sizable crops in full shade. It was also formerly used as a source of thread for basket making. Its flowers evolved before bees, so they smell like carrion and are beetle pollinated! Its seeds kind of get in the way, so I’m going to try to create a seedless triploid version. Well, I don’t actually know its ploidy level, so I’m going to try to create an uneven ploidy level to aim to produce seeds which do not develop. Same for the honey locust, which can produce 200 lbs per tree per year up to 36% sugar. One of mine, with a 20×30′ spread had ~160 lbs, but was probably just 20% sugar. (It has shown itself to be biennial.) At 50 trees per acre, that’s 10,000 lbs. That’s 6.5 million calories of sugar at 36% sugar and 4 cal/g. At 300 lbs, 36% sugar, and 70 trees per acre, it’s 13.5 million calories. If sugar content were 50%, it’d be around 19 million calories, which would be on par with average US corn production per acre (1), with far less annual energy input. Fundamentally, trees and plants do not reach peak physical photosynthesis; their production can be massively improved. Trees are far more resilient to intermittent droughts and can induce rain, at scale.
I also aim to help bring back threatened species, such as the ashes, elms, and chestnuts.
Tannin in Chinese ashes is what deters the Emerald Ash Borer, and that’s also the reason why the EAB prefers Green Ashes to White Ashes. The Green Ash, however, being a pioneer species, short lived, and near waterways, means that the ephemeral ponds in which its leaves decay often have low tannin levels, to which certain tree frog tadpoles are adapted. If we bred the trees to have high tannin levels, that could lead to many unknown consequences, such as for dragonfly nymphs or crawfish. Decisions cascade in consequence.
The Ozark Chinquapin Chestnut is a local treasure. It’s a tree sometimes 3′ wide and 70′ tall, with a single nut in each bur. At 15% protein and 14% fat, it is the lowest-fat high-protein nut, and the 7th highest protein tree nut. 15% protein is very high, and that it’s from a relatively drought tolerant Castanea species is really unique. The Ozark Chinquapin Foundation has done a superb job to bring back the native species from seed. Chestnuts are unique among trees for having a starchy seed and for having a consistent yearly crop, making them a food crop long utilized by humans across all continents. Castanea Henryi may have similar protein, according to a single source, with less fat, but I think it is likely less drought tolerant due to the region from which it hails. (Sources will be provided at a later date, when I have more time.)
For that matter, I think it’s unwise to start mass production of Castanea Henryi, because it is non-native. Chestnuts hybridize freely, but first generation hybrids tend to be male-infertile. Unknown unknowns are the biggest issue humans currently face regarding how we have terraformed our sole habitat. Introgression and interspecific hybridization ought to be avoided at virtually all costs. I would strongly encourage people to think about genetic diversity. For instance, the Ozark Chinquapin Foundation has done more in 15 years than the American Chestnut Foundation has done in 100+, precisely by utilizing best practices like oxalic acid leaf assays as a proxy for fungal resistance, while documenting parentage, and continually attempting to broaden the genetic background via accession of new trees to their classical breeding program. While I intend to introduce several new cultivars of wild trees into the nursery trade, I would strongly advise against anyone doing so for wild trees that are coming back from a genetic bottleneck event, such as Castanea Ozarkensis. (I would also seriously, strongly advise laws to protect the commons from actors who might not have thought through such scenarios, even though I would assume that’s a nigh impossible regulation to create.)
Aside from oxalic acid leaf assays, new research into viruses that attack fungal cankers, mycoviruses, is of the utmost priority. This is particularly important to broaden the gene pool of bottlenecked species, once resistance has been stabilized. It is also important for future fungal tree epidemics, such as butternut canker (on butternut, possibly also mockernut) or thousand canker disease (black walnut).
Red Mulberry bark was once used for thread, said to be finer than silk. Many trees in the Moracea genus have had bark used for thread, across 4 or 5 continents. Red Mulberry and Bois D’arc have leaves which can be fed to the domesticated silk worm. Red mulberry is among the most rot resistant of woods, but weak, light, and fast growing. It can grow over 1″ per year in diameter, and can last decades outside without insect or fungal damage. Its fruit is very tasty, able to be dried. Female red mulberries are actually hypo-allergenic! They absorb pollen of all species! The leaves on my tree in Hochatown often measure over 14″. Catalpa, especially after coppicing/pollarding, have similarly large leaves. As both trees evolved to have their leaves frequently defoliated, that presents an opportunity to create less chemically intensive, and more compostable, ‘paper plates’. Catalpa trees can produce up to five broods of worms per year, one of the world’s most sustainable sources of insect protein! Plus an extremely fat-growing, rot-resistant timber.
Self-fruitful American Persimmons exist, such as Yates or Meader. These produce seedless fruit in the absence of males, which is difficult to achieve in many parts of America. An aneuploid offspring from one of these, particularly one fertilized with male pollen from a tree with a high amount of heartwood would almost certainly result in a tree that creates a sustainable ebony industry, and has consistently seedless crops, regardless of proximity to males.
We’re entering the golden age of genomic research. Polygenetic genes and epigenetics are subjects about which our collective knowledge is currently growing exponentially. As DNA testing falls in price, and more organisms have their DNA fully mapped, we will be able to create new plants in ways few people have considered. Many people may think that much of that must be done in some urban lab, but they’re flatly wrong. One of the most important aspects of genetic manipulation is ensuring that the transgenic genes input into the GMO do not spread into wild populations. It’s absurd that it’s not standard practice to first induce stable higher order polyploids. (The black mulberry is tetratetracontaploid, aka 44 ploidy, N=7. Wheat is often sextaploid or octaploid. Strawberries are octaploid. There’s no reason that the process for induced ploidy cannot be improved.)
*Bois D’arc fruit is often cited as being larger on average than paw paws, and is also often cited as being “inedible”. While it’s certainly not palatable, Bois D’arc fruit does not seem to be poisonous, and is often larger on average among wild cultivars of both species. It is important to note that the seeds of Bois D’arc are edible and tasty, when properly prepared.
(1) https://ipad.fas.usda.gov/countrysummary/Default.aspx?id=US&crop=Corn
shows roughly 11 T/ha which equates to roughly 10,000 lbs/acre, as corn is ~1650 cal/lb (https://www.fatsecret.com/calories-nutrition/usda/yellow-corn?portionid=48531&portionamount=1.000)
