Solanum candolleanum

Description

Solanum candolleanum (candolleanum, in honor of Swiss botanist Agustin Pyramus de Candolle) is primarily a Peruvian species, but also found in Bolivia.  Plants large, as much as three feet tall, although this is quite a variable species.  Stolons reach almost five feet.  Large tubers, maybe the largest of any of the wild potatoes, reaching up to about five inches long or more under cultivation.  Flowers blue to purple.  Berries round to ovoid and similar in size to domesticated potato.  Grows in cool, moist environments up to about the 13,100 foot elevation.

S. candolleanum and S. brevicaule can probably be considered the core members of the Solanum brevicaule complex, which ranges from northern Peru through Bolivia.  S. candolleanum is the dominant species in the northern part of that range and S. brevicaule is in the southern part.  Both species are highly variable, but overall similar to one another.  Both share a lot of similarities with the domesticated potato and can cross relatively easily with it, at least at the diploid level.

Resistances

This species can survive frosts down to 24 degrees F (-4.5 C) (Li 1977, as S. canasense).  Vega (1995) found that this species is more frost tolerant than domesticated potato.

Condition	Type	Level of Resistance	Source
Drought	Abiotic	Somewhat resistant	Machida-Hirano 2015, Watanabe 2011 (as S. chillonanum)
Frost	Abiotic	Somewhat resistant	Machida-Hirano 2015
Globodera pallida (Pale Cyst Nematode)	Invertebrate	Somewhat resistant	Castelli 2003
Globodera pallida (Pale Cyst Nematode)	Invertebrate	Somewhat resistant	Bachmann-Pfabe 2019 (under various synonyms
Globodera rostochiensis (Potato Cyst/Golden Nematode)	Invertebrate	Resistant	Castelli 2003
Leptinotarsa decemlineata (Colorado Potato Beetle)	Invertebrate	Somewhat resistant	Machida-Hirano 2015
Meloidogyne spp. (Root Knot Nematode)	Invertebrate	Somewhat resistant	Machida-Hirano 2015
Myzus persicae (Green Peach Aphid)	Invertebrate	Somewhat resistant	Machida-Hirano 2015
Pectobacterium carotovorum (Blackleg/Soft Rot)	Bacteria	Somewhat resistant	Chung 2011 (as S. bukasovii)
Phytophthora infestans (Late Blight)	Fungus	Not resistant	Gonzales 2002
Phytophthora infestans (Late Blight)	Fungus	Somewhat resistant	Bachmann-Pfabe 2019 (under various synonyms)
Potato Leaf Roll Virus (PLRV)	Virus	Somewhat resistant	Machida-Hirano 2015 (as S. bukasovii)
Potato Virus Y (PVY)	Virus	Somewhat resistant	Chung 2011, Machida-Hirano 2015
Potato Virus Y (PVY), C Strain	Virus	Resistant	Takacs 1999 (as S. achacachense)
Streptomyces scabiei (Scab)	Bacterium	Somewhat resistant	Machida-Hirano 2015 (as S. bukasovii)
Synchytrium endobioticum (Wart)	Fungus	Somewhat resistant	Machida-Hirano 2015

Glykoalkaloid content

Johns (1990) found glycoalkaloid levels ranging from mostly from 25 to 78mg/100g in four accessions of S. candolleanum (as S. bukasovii and S. canasense).  They also noted an outlier at 9mg/100g (PI 473492).  Some have levels are just above the safety limit for S. tuberosum at 20mg/100g and those are probably safe to eat in small amounts.  Some varieties may even be as safe as S. tuberosum if the 9mg/100g outlier is any indication.  The primary glycoalkaloids found were solanine and chaconine.  Van Gelder (1988) found TGA levels ranging from 70 to 92 mg / 100 g (as S. bukasovii), 32 to 36 mg / 100 g (as S. canasense), and 36 mg / 100 g (as S. multidissectum).

Images

Cultivation

The USDA potato genebank has observed that some accessions of this species are dependent upon GA3 for germination (Bamberg 1999).  Bamberg (2018) found that alternating temperatures increased germination in this species.

Breeding

Crosses with S. tuberosum

Female	Male	Berry Set	Seed Set	Germ	Ploidy	Source
S. candolleanum (inlcuding many synonyms)	S. tuberosum 4x	Minimal	Minimal			Jackson (1999)
S. tuberosum 4x	S. candolleanum (including many synonyms)	Low	Minimal			Jackson (1999)

Crosses with other species

Jackson (1999) found 3-12% 2n pollen for varieties of this species.

Female	Male	Berry Set	Seed Set	Germ	Ploidy	Source
S. candolleanum	S. acaule	High	High			Ochoa 1990
S. candolleanum	S. berthaultii (as S. litusinum)	Moderate	Moderate			Ochoa 1990
S. candolleanum	S. brevicaule	Moderate	Moderate			Ochoa 1990
S. candolleanum	S. boliviense	Moderate	Moderate			Ochoa 1990
S. candolleanum	S. infundibuliforme	Moderate	Moderate			Ochoa 1990
S. candolleanum	S. lignicaule	No?	No			Ochoa 1990
S. candolleanum	S. microdontum	Yes?	No			Ochoa 1990
S. candolleanum	S. raphanifolium	High	High			Ochoa 1990
S. candolleanum	S. stipuloideum (as S. circaefolium)	No?	No			Ochoa 1990
S. boliviense (as S. megistacrolobum)	S. candolleanum	Yes?	No			Ochoa 1990

References

Solanum candolleanum at Solanaceae Source

Solanum candolleanum at GRIN Taxonomy

Solanum candolleanum at CIP