|Tuberization Photoperiod||Short Day|
|Citation||Ochoa: Agronomía (Lima) 26(4): 314. 1959.|
Solanum cajamarquense is an unusual speces, with a small distribution in northern Peru. It grows at mid-elevations of the Andes from about 6500 to 8500 feet. Plants roughly 16 to 20 inches tall. Stolons long, exceeding two feet. Tubers small and moniliform, like beads on a string. Flowers white. Berries small, less than 1/2 inch, round, striped. The specific epithet, cajamarquense, refers to Cajamarca Department, Peru.
Li (2018) placed this species in Clade 3, a group of Andean diploids, but closely neighboring Clade 1+2, North American 1EBN diploid species.
Some plants of this species produce very heavy trichomes, which presumably acts as an insect deterrent.
|Condition||Type||Level of Resistance||Source|
|Phytophthora infestans (Late Blight)||Fungus||Resistant||Gonzales 2002, Perez 2007|
I have found germination of this species to be very slow, taking between one and three months. I haven’t had much luck getting tubers bigger than pinheads from this species, even when the plants are left to grow into November or December.
The pesticide carbofuran has been observed to reduce flowering in this species (Centeno-diaz 2007).
The following accessions were examined to prepare this profile. I have evaluated 2/2 accessions currently available from the US Potato Genebank.
Poor germination and relatively slow seedling growth. Dark colored seedlings. Leaves with purple undersides. Some with purple veins as well. Some with lots of very pretty blue flowers. The GRIN page for this accession lists it as S. cajamarquense, but also indicates that it is hybrid seed with PI 275149, which is an accession of S. boliviense. I inquired with the genebank and they confirmed that it is a hybrid and also provided data showing that most attempts at seed increases have failed. They also confirmed that this accession has counted out as diploid in root tip counts. This cross would presumably produce triploid (2/3 CJM and 1/3 BOL) progeny and the plants did not produce berries here when pollinated by true S. cajamarquense, which is consistent with that. A diploid result from this cross does not make sense to me, due to the differences in EBN. My best guess is that the original hybrids were triploid and 2EBN. Perhaps those were bulked together for seed, giving aneuploids between diploid and triploid and stabilizing toward diploid. This often seems to be the case with interspecies odd-ploidy hybrids.
I also noticed that Binquan (2019) reported that this accession grouped in such a way that it suggested introgression from clade 4, which is consistent with its hybrid nature.
Good germination and relatively strong seedling growth. Light colored, pubescent seedlings. Leaves with green undersides.
Crosses with S. tuberosum
Crosses with other species