and colleagues admiring plants along roadside during a collecting expedition.Dr. Charles Rick
The domestication of the wild cherry types (L. esculentum var. cerasiforme) in Mexico eventually spread to Europe and by selection led to larger fruited varieties. It is believed that this selection also led to the progressive withdrawal of the stigma into the anther cone (probably by chance). This gave rise to the large-fruited self-compatible inbreeders most of us grow in our gardens today. For this reason it is relatively easy for one to maintain a "true-to-type-variety" (as long as the variety is not a F1 hybrid) by saving their own seed and not have to worry too much about outcrossing with other varieties of tomato.
Most, but certainly not all, L. esculentum are red fruited. Fruit color, shape and quality vary considerably as does growth habit and leaf morphology.
There are several other botanical varieties of tomato. These varieties can be easily intercrossed with each other to produce viable offspring. They are:
Interim Report of the Committee on Varietal Pedigrees 1995-60
Interim Report of the Committee on Varietal Pedigrees 1984
This species tends to readily cross with L. escuentum and is the only one to have exhibited a natural introgression with L. esculentum . In fact it is probable that both species evolved from a common ancestor.
There are thousands of PI's (Plant Introductions) of L. pimpinellifolium. Many of which have been incorporated into L. esculentum to provide useful resistance to several diseases.
Fruit storage life in Lycopersicon pimpinellifolium. (Lobo, M., Alvaran, I. and Cardona, M.P.)
An anomalous accession of L. pimpinellifolium from the Galapagos Islands. (Rick, C. M.)
This species is found exclusively in the Galapagos Islands. A subspecies exists , L.cheesmanii subspp. minor, which is generally found in the drier regions of the islands while L.cheesmanii is found closer to the coastal areas. The fruits are red to orange. All forms of L.cheesmanii are self-compatible and exclusively inbreeders. Both forms can be hybridized with the common tomato.
"L. cheesmanii f. minor
L.cheesmanii has provided several benifits to the common tomato. The first is the incorporation of a single recessive gene that codes for jointless pedicels. This is oftened used as a genetic marker. L.cheesmanii also can be used for its high vitamin C, pro vitamin A and higher soluble solids contents. The subspecies, L.cheesmanii subspp. minor, has the potential for salt and drought tolerance.
Potential of Lycopersicon cheesmanii accessions for improving provitamin A content in tomato. (Stommel, J.R.)
Transfer of 'High Solids' genes from Lycopersicon cheesmanii and L. chmielewskii to tomato. (Poysa, V.)
The use of Lycopersicon cheesmanii in breeding for salt-tolerant tomatoes. (Costa, J., Nuez, F., Anastasio, G. and Palomares, G.)
Sucrose accumulator (sucr), a gene controlling sugar composition in fruit of L. chmielewskii and L. hirsutum. (Chetelat, R.T., et.al.)
This species is native to Peru and southern parts of Ecuador and has very small, green, hairy fruit. The species is divided into to seperate subspecies, L. hirsutum f. typicum and L. hirsutum f. glabratum.
L. hirsutum f. glabratum
L. hirsutum f. typicum is often found in higher elevations river valleys (between 1,800 and 3,300m) from southern Ecuador to central Peru. It is a strong outbreeder with a very long exerted stigma. Most PI's are self-incompatible. Those that have permitted selfing produce weak progeny which suffer greatly from inbreeding depression. This subspecies does not readily cross with L. esculentum. The other subspecies, L. hirsutum f. glabratum, easily accomodates self-fertilization and progeny do not suffer from inbreeding depression. It is found in the southwestern parts of Ecuador at lower latitudes (0-6 degrees south). This subspecies is capable of crossing with L. esculentum.
L. hirsutum has been noted for several resistances to pests. One trait is that of resistance to two species of red spider mite. This is a physical rather than a biochemical mechanism. Mites become tangled in sticky substances which are secreted by the glandular hairs (trichomes). L. hirsutum also has a high concentration of a naturally occuring pesticide, 2-tridecacone, in the plant. This provides a high degree of protection against aphids and lepidopteran larvae (caterpillars).
L. hirsutum has also been a source of resistance to pathogens such as early blight (PI 126445), bacterial speck and root-knot nematodes. L. hirsutum f. typicum has also been investigated as a source of cold tolerance.
Late blight horizontal resistance in L. hirsutum. (Lobo, M. and R. Navarro.)
Resistance to potato virus Y and cucumber mosaic virus in Lycopersicon hirsutum. (Gebre-Selassie, K., et.al.)
syn. Solanum pennelliiThough not considered by some authorities to be a true Lycopersicon species, I will include this species as well. (It is considered to be Solanum pennellii). It is readily crossable to L.esculentum as well. Both self-compatible and self-incompatible types exist. This species evolved in hot, dry enviroments and may prove to be a source of drought resistance and insect tolerance. It is native to coastal areas of Peru and has small green fruit.
Acylsugars of L. pennellii deter feeding and oviposition of the leafminer L. trifolii. (Hawthorne, D.J., et.al.)
Resistance to race O of Pseudomonas syringae pv. tomato in wild Lycopersicon species. (Bogatsevska, N., Sotirova, V.)
Screening for salintiy tolerance in the genus Lycopersicon. (Hassan, A.A., Al-Afifi, M.A., Matsuda, K., Koto, A. and Itani, S.)
Sources of resistance to fusarium wilt race 3. (Scott, J.W. and Jones, J.P.)