Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 233

Tomato (Solanum lycopersicum) is very important vegetable both for the fresh market and for the processed food industry. Although cultivated as an annual, tomato grows as a perennial in its original habitat in Peru (Picken et al. 1985). The original site of domestication of tomato is likely in Mexico (Taylor 1986).

According the recent classification, tomato belongs to section Lycopersicon and has 12 wild relatives (Table B5.1). Of these 12 relatives, nine (no. 1 to 9 in Table B5.1) are previously defined in the genus of Lycopersicon (refer to as old Lycopersicon species). Accessions of nearly all these nine species have been successfully used to introduce valuable traits for crop improvement, especially monogenic sources conferring resistance to fungal, nematode, bacterial, and viral diseases. (Kiss, L. and Takamatsu, S. 2005). The phelogenic relation of these old Lycopersicon species with cultivated tomato has been extensively studied, based on comparative analysis of morphology, self‐compatibility, crossability, and molecular markers. The classical taxonomic characters which have been used to divide old Lycopersicon species are fruit color and self‐compatibility. In the phylogeny generated with molecular markers, different patterns of species relationships have been obtained, some of which are congruent with results of classical taxonomy and others add resolution to new divisions that are always in agreement. In general, we could conclude the following (i) species (S. lycopersicum, S. lycopersicum var cerasiforme, Solanum cheesmaniae, Solanum pimpinellifolium) with self‐compatibility and red fruits; (ii) Solanum peruvianum and Solanum chilense (green fruits and self‐incompatible) are closely related species; and (iii) species with green fruits, including Solanum chmielewskii, Solanum neorikii, Solanum habrochaites, and Solanum pennellii, have varied relationships with the rest depending on markers used for phylogeny.

Table B5.1 Old and new names of tomato and its wild relatives.

No.	New Solanum name	Lycopersicon equivalent	Fruit color	Self‐compatibility	Ability to be crossed with other Solanum species	Section name within Solanum
1	Solanum lycopersicum	Lycopersicon esculentum	Red	Self‐compatible	Old “esculentum” group, crossable among these species, although it is sometimes only possible in one direction to make crosses	Section Lycopersicon
2	S. pimpinellifolium	L. pimpinellifolium	Red
3	S. cheesmaniae	L. cheesmaniae	yellow
4	S. chmielewskii	L. chmeilewskii	Green
5	S. neorickii	L. parviflorum	Green
6	S. habrochaites	L. hirsutum	Green	Self‐incompatible
7	S. pennellii	L. pennellii	Green
8	S. chilense	L. chilense	Green	Old “peruvianum” group, crossable between these two species, but difficult to cross them with cultivated tomato and embryo rescue is often needed
9	S. peruvianum	L. peruvianum	Green
10	S. lycopersicoides	L. lycopersicoides	Green‐black	Most closely related to old Lycopersicon species and crossable to S. lycopersicum, S. cheesmaniae, S. pimpinellifolium, and S. pennellii
11	S. sitiens	L. sitiens	Green	Also known as S. rickii, Crossable with S. lycopersicoides
12	S. ochranthum	L. ochranthum	Green	Unknown crossability with other Solanum species	Section Juglandifolium
13	S. juglandifolium	L. juglandifolium	Green	Unknown crossability with other Solanum species