Solanum violaceimarmoratum

Description

Solanum violaceimarmoratum distribution map
Solanum violaceimarmoratum distribution map

Solanum violaceimarmoratum is native to the eastern slopes of the Bolivian Andes, at elevations of roughly 6500 to 11200 feet.  An unusual species, thought not to be closely related to other wild potatoes.  Very tall plants, reaching nine feet in height.  Stolons three feet or more.  Tubers reaching two to three inches in length, more in cultivation.  Some sources report that the tubers are moniliform, but I haven’t observed this.  Tuber skin ranges from white to purple and flesh color white to light yellow.  Tubers become dark purple with exposure to light.  Purple flowers.  Berries conical.

The specific epithet, violaceimarmoratum, means “purple mottled” and probably refers to the stems.  It is formed from the Latin words “violaceus,” for “violet,” and “immarmoratus,” for “marbled.”  While there is no completely standardized pronunciation for scientific names, the most common way to pronounce this species is probably so-LAY-num vie-oh-lay-see-mar-moh-RAH-tum.

This species can survive frosts down to 27 degrees F (-3 C) (Li 1977), about the same as the domesticated potato.  Even though it grows at relatively high elevations, It has poor frost resistance compared to most wild potatoes, most likely because the eastern slopes of the Andes to which it is native are warmed by updrafts from the Amazon basin (Smillie 1983).  It grows in sandy clay soils, developing best in loose, moist soils with high organic matter (Patiño 2008).

Subramanian (2017) found that at least some accessions of this species have unusually high potassium content.

This species has been tentatively classified as vulnerable on the IUCN Red List (Cadima 2014).

Condition Type Level of Resistance Source
Alfalfa Mosaic Virus (AMV) Virus Resistant Horvath 1989
Cucumber Mosaic Virus (CMV) Virus Resistant Horvath 1989
Frost Abiotic Not resistant Li 1977, Smillie 1983
Globodera pallida (Pale Cyst Nematode) Invertebrate Not resistant Castelli 2003
Globodera rostochiensis (Potato Cyst/Golden Nematode) Invertebrate Resistant Nagaich 1980
Globodera rostochiensis (Potato Cyst/Golden Nematode) Invertebrate Not resistant Castelli 2003
Pectobacterium carotovorum (Blackleg/Soft Rot) Bacteria Somewhat resistant Chung 2011
Phytophthora infestans (Late Blight) Fungus Resistant Gonzales 2002
Potato Virus X (PVX) Virus Resistant Horvath 1989
Potato Virus Y (PVY) Virus Not resistant Cai 2011
Sclerotinia sclerotiorum (White Mold) Fungus Resistant Jansky 2006

Glykoalkaloid content

I have found no published information about glycoalkaloids in this species.  I have tasted the tubers of some seedlings and found most of them palatable, while some produce a slight sour sensation at the back of the mouth.

Images

Solanum violaceimarmoratum plant
Solanum violaceimarmoratum plant
Solanum violaceimarmoratum plant
Solanum violaceimarmoratum plant
Solanum violaceimarmoratum flower buds
Solanum violaceimarmoratum flower buds
Solanum violaceimarmoratum flower
Solanum violaceimarmoratum flower
Solanum violaceimarmoratum inflorescence
Solanum violaceimarmoratum inflorescence
Solanum violaceimarmoratum plant
Solanum violaceimarmoratum plant
Solanum violaceimarmoratum inflorescence
Solanum violaceimarmoratum inflorescence
Above ground plant of the wild potato species Solanum violaceimarmoratum
Solanum violaceimarmoratum plant
Berries of the wild potato species Solanum violaceimarmoratum
Solanum violaceimarmoratum berries
Berries of the wild potato species Solanum violaceimarmoratum
Solanum violaceimarmoratum berries
Tubers of the wild potato species Solanum violaceimarmoratum
Solanum violaceimarmoratum tubers
Tubers of the wild potato species Solanum violaceimarmoratum
Solanum violaceimarmoratum tubers

Cultivation

I have found seeds of this species slow and difficult to germinate using the standard conditions for S. tuberosum.  Overall, I was surprised by how happy and healthy this species seems to be in our climate.  Plants grow very large and persist late into the year in excellent condition.  In 2018, a plant that was surrounded by other potato species that were infected with late blight showed no symptoms at all.  I kept that clone for further investigation and plan to attempt crosses with domesticated diploids.

Towill (1983) found that seeds of this species stored at 1 to 3 degrees C germinated at 70% after 10 years.

Tubers have at least four months of dormancy.

Trapero-Mozos (2018) determined that this species will tolerate a temperature of 40 C after acclimation for a period of time at 25 C.

Breeding

Crosses with S. tuberosum

I have found that S. violaceimarmoratum crosses easily with diploid S. tuberosum.

Watanabe (1991) found that 2.8% of varieties of this species produced 2n pollen, which would be effectively tetraploid and 4EBN.

Female Male Berry Set
Seed Set Ploidy Germ Source
S. violaceimarmoratum S. tuberosum None None Jackson (1999)

Crosses with other species

Female Male Berry Set
Seed Set Ploidy Germ Source
S. violaceimarmoratum S. stipuloideum (as S. circaefolium and var. capsibaccatum and var circaefolium)  Low Very Low  Yes Ochoa 2004
S. stipuloideum (as S. circaefolium and var. capsibaccatum and var circaefolium) S. violaceimarmoratum Low  None Ochoa 2004
S. violaceimarmoratum S. commersonii  No No Ochoa 2004
S. commersonii S. violaceimarmoratum  No  No Ochoa 2004
S. violaceaimarmoratum S. laxissimum High High  Yes Ochoa 2004
S. laxissimum S. violaceaimarmoratum High High Ochoa 2004
S. violaceaimarmoratum S. limbaniense  High High  Yes Ochoa 2004
S. limbaniense S. violaceaimarmoratum  High  High Ochoa 2004
S. violaceaimarmoratum S. rhomboideilanceolatum  High  High  Yes Ochoa 2004
S. rhomboideilanceolatum S. violaceaimarmoratum High High Ochoa 2004
S. violaceaimarmoratum S. chomatophilum No No Ochoa 2004
S. chomatophilum S. violaceaimarmoratum No No Ochoa 2004
S. violaceaimarmoratum S. humectophilum None None Ochoa 2004
S. humectophilum S. violaceaimarmoratum Low Low Ochoa 2004

References

Solanum violaceimarmoratum at Solanaceae Source

Solanum violaceimarmoratum at GRIN Taxonomy