Solanum guerreroense

Description

Solanum guerreroense distribution map
Solanum guerreroense distribution map

Solanum guerreroense is a species of very limited distribution in Guerrero, Mexico, where it grows in conifer and oak forests.  It is only known from a single collection and expeditions since have failed to locate any plants (Spooner 2004).  It may be synonymous with S. iopetalum (Marks 1965), although the plants that I have grown of each species do not look similar.  Plants are low growing and can reach about nine inches tall.  Violet flowers (although I have seen white with only a hint of purple).  Tubers to about two inches, russet to purplish (Correll 1962).  Berries are described in several sources as being conical, but I have only seen round berries.

The specific epithet, guerreroense, refers to Guerrero, Mexico.  While there is no completely standardized pronunciation for scientific names, the most common way to pronounce this species is probably so-LAY-num gair-air-oh-EN-see.

Morphologically, this plant fits with a number of geographically separate rosette forming species, including South American species like S. acaule and S. albicans and North American species like S. demissum.

Watanabe (1994b) found that this species has disomic chromosome segregation, in common with most of the North American polyploid species.

1400 seeds per gram.

Resistances

Carlson-Nilsson (2010) found that the foliage of this species was very resistant to late blight, but the tubers only moderately resistant.

Zoteyeva (2014) found that this species carries the R3 late blight resistance gene, but also displays hypersensitive resistance when this gene is not present, indicating the presence of additional resistance factors.

Luthra (2007) found that this species is moderately resistant to frost damage, equal to the least frost resistant accessions of S. tuberosum subsp. andigenum.

Varieties derived from the breeding line PALB03016-3, which includes S. guerreroense genetics, have shown resistance to zebra chip (Rondon 2012).  This probably indicates that this species carries resistance to the putative causal organism Liberibacter solanacearum.

Condition Type
Level of Resistance Source
Globodera rostochiensis (Potato Cyst/Golden Nematode) Invertebrate Not resistant Castelli 2003
Globodera rostochiensis (Potato Cyst/Golden Nematode) Invertebrate Not Resistant Castelli 2003
Liberibacter solanacearum (Zebra Chip) Bacterium Resistant Rondon 2012
Meloidogyne spp. (Root Knot Nematode) Invertebrate Not Resistant Janssen 1995
Myzus persicae (Green Peach Aphid) Invertebrate Somewhat Resistant Radcliffe 1981
Pectobacterium carotovorum (Blackleg/Soft Rot) Bacterium Somewhat Resistant Lojkowska 1989
Phytophthora infestans (Late Blight) Fungus Resistant Black 1957, Douches 2001, Gavrilenko 2017
Potato Leafroll Virus (PLRV) Virus Not Resistant De Galarreta 1998
Potato Spindle Tuber Viroid (PSTVd) Virus Somewhat Resistant Sofy 2013, Machida-Hirano 2015
Potato Virus M (PVM) Virus Not Resistant De Galarreta 1998
Potato Virus S (PVS) Virus Not Resistant De Galarreta 1998
Potato Virus X (PVX) Virus Somewhat Resistant Turuleva 1990, Kiru 2008
Potato Virus X (PVX) Virus Not Resistant Zoteyeva 2012
Potato Virus Y (PVY) Virus Somewhat Resistant Turuleva 1990, Gavrilenko 2017
Verticillium spp. (Verticillium Wilt) Fungus Not Resistant Graebner 2018

Glykoalkaloid content

Tubers that I have sampled had a pleasant flavor with perhaps just a hint of bitterness.

Images

Solanum guerreroense plant
Solanum guerreroense plant
Solanum guerreroense plant
Solanum guerreroense plant
Solanum guerreroense flower
Solanum guerreroense flower
Solanum guerreroense berry
Solanum guerreroense berry
Solanum guerreroense plant
Solanum guerreroense plant
Solanum guerreroense berries
Solanum guerreroense berries
Solanum guerreroense seeds
Solanum guerreroense seeds
Tubers of the wild potato species Solanum guerreroense
Solanum guerreroense tubers

Cultivation

I have found this species easy to germinate, taking about the same amount of time as S. tuberosum.

Plants of this species are small and low growing.  It will not compete well with taller companions or weeds that are not well controlled.  This would be an excellent plant for a high density planting in a raised bed.

I have noted a lot of size variance in ripe berries compared to other species.  Berries should be harvested frequently when they begin to soften because they lie on the ground and are vulnerable to slug and insect damage.

Hawkes (1956) reported that, although this species is self-fertile, it requires hand pollination in order to set seed.  I have not observed this to be true.  Plants grown here easily set selfed berries with no intervention.  The difference can probably be accounted for by growing conditions: I grow outdoors but most potato research takes place in greenhouses.

Towill (1983) found that seeds of this species stored for 12 years and 1 to 3 degrees C germinated at 100%.

Breeding

This species appears to be essentially cleistogamous, self-fertilizing as soon as the flowers open or possibly even earlier.  Under our conditions, every flower forms a berry.

Watanabe (1991) found that 100% (of only two plants) of varieties of this species produced 2n pollen.  On the other hand, Zlesak (2002) found that 0% of 12 plants produced 2n pollen.

Crosses with S. tuberosum

Gavrilenko (2017) was able to select male fertile varieties with a high degree of late blight resistance from a population of S. guerreroense x S. tuberosum subsp. andigenum hybrids.

Female Male Berry Set
Seed Set Germ Ploidy Source
S. guerreroense S. tuberosum Low Moderate Jackson (1999)
S. guerreroense S. tuberosum (cv. Superb) Yes Yes Carlson-Nilsson (2010)
S. guerreroense S. tuberosum subsp. andigenum Yes Yes Carlson-Nilsson (2010)
S. tuberosum S. guerreroense Minimal None Jackson (1999)

Crosses with other species

In crosses between the Mexican hexaploid species, Hawkes (1956) found that only the progeny of the S. guerreroense x S. iopetallum cross set seed successfully.

Female Male Berry Set
Seed Set Germ Ploidy Source
S. demissum S. guerreroense Yes Yes Hawkes (1956)
S. guerreroense S. demissum Yes Yes Hawkes (1956)
S. guerreroense S. hougasii (as S. spectabile) Yes Yes High Hexaploid Hawkes (1956)
S. guerreroense S. iopetalum (as S. brachycarpum) Low Low High Hexaploid Hawkes (1956)

References

Solanum guerreroense at Solanaceae Source

Solanum guerreroense at GRIN Taxonomy

Solanum guerreroense at CIP