Solanum jamesii as a Food Crop: History and Current Status of a Unique Potato

Solanum jamesii is a wild potato found in the US southwest. There is ample evidence that this potato was used by ancestral Puebloans as a food source, where some researchers think it was used as a starvation food while others consider it to be regular food source. Currently this potato is being grown by Native Americans, notably the Navajo, as a specialty food as well as a food crop. There are several attributes to this potato that make it especially suitable for development as our climate changes and food needs become more demanding, including its drought tolerance and ability to be crossed with other wild potato species and cultivars.

Plant species richness at archaeological sites suggests ecological legacy of Indigenous subsistence on the Colorado Plateau

Humans have both intentional and unintentional impacts on their environment, yet identifying the enduring ecological legacies of past small-scale societies remains difficult, and as such, evidence is sparse. The present study found evidence of an ecological legacy that persists today within an semiarid ecosystem of western North America. Specifically, the richness of ethnographically important plant species is strongly associated with archaeological complexity and ecological diversity at Puebloan sites in a region known as Bears Ears on the Colorado Plateau. A multivariate model including both environmental and archaeological predictors explains 88% of the variation in ethnographic species richness (ESR), with growing degree days and archaeological site complexity having the strongest effects. At least 31 plant species important to five tribal groups (Navajo, Hopi, Zuni, Ute Mountain Ute, and Apache), including the Four Corners potato (Solanum jamesii), goosefoot (Chenopodium sp.), wolfberry (Lycium pallidum), and sumac (Rhus trilobata), occurred at archaeological sites, despite being uncommon across the wider landscape. Our results reveal a clear ecological legacy of past human behavior: even when holding environmental variables constant, ESR increases significantly as a function of past investment in habitation and subsistence. Consequently, we suggest that propagules of some species were transported and cultivated, intentionally or not, establishing populations that persist to this day. Ensuring persistence will require tribal input for conserving and restoring archaeo-ecosystems containing “high-priority” plant species, especially those held sacred as lifeway medicines. This transdisciplinary approach has important implications for resource management planning, especially in areas such as Bears Ears that will experience greater visitation and associated impacts in the near future.

Physiology of tuber dormancy and its mechanism of release in potato

The tuber dormancy is an important aspect of tuber’s physiological age and begins with tuber initiation. It is largely dependent on genotype, environmental conditions, and tuber age. The group Phureja among diploid potatoes, has a very short or no tuber dormancy while the tubers of Solanum jamesii, a wild potato species, may remain dormant for more than eight years and have the tendency to sprout in favourable conditions. The dormancy breakage in potato is accompanied by many physiological changes such as changes in the ratios of abscisic acid (ABA)/ cytokinin and ABA/ gibberellic acid (GA3), catalase inhibition and accumulation of soluble sugars. These all changes are interlinked and occur in the same time frame. The dormant buds have 77% of their nuclei in the growth phase (G1), compared to only 13% in the preparation phase for mitosis (G2), resulting in slower development of active buds. This paper reviews various factors involved in natural and forced dormancy breakage of potato tuber in relation to their use as seed potatoes immediately after harvesting and implementation of different exogenous dormancy breaking methods like cold pre-treatment, growth regulators, electric current and irradiation to induce sprouting in potatoes.

Starch granule evidence for the earliest potato use in North America

The prehistory of wild potato use, leading to its domestication and diversification, has been well-documented in, and confined to, South America. At least 20 tuber-bearing, wild species ofSolanumare known from North and Central America, yet their importance in ancient diets has never been assessed from the archaeological record. Here, we report the earliest evidence of wild potato use in North America at 10,900–10,100 calendar years (cal) B.P. in the form of well-preserved starch granules extracted from ground stone tools at North Creek Shelter, southern Utah. These granules have been identified as those ofSolanum jamesiiTorr. (Four Corners potato), a tuber-bearing species native to the American Southwest. Identification was based on applying five strictly defined diagnostic characteristics (eccentric hilum, longitudinal fissure, lack of fissure branching, fissure ratio, and maximum granule size) to each of 323 archaeological granules. Of those, nine were definitively assigned toS. jamesiibased on possession of all characteristics, and another 61 were either likely or possiblyS. jamesiidepending on the number of characteristics they possessed. The oldest granules were found in substratum 4k (10,900–10,100 cal B.P.). Younger deposits, dating to ∼6,900 cal B.P., also contained tools withS. jamesiigranules, indicating at least 4,000 y of intermittent use. Ethnographic and historical accounts extend the period of use to more than 10,000 y. The question then arises as to whether someS. jamesiipopulations could have undergone transport, cultivation, and eventual domestication over such a long period of time.