Study of the three-genome hybridLycopersicon esculentum Mill. ?L. chilense Dun. ?L. peruvianum var ?humifusum? Mill. and its use as a source for resistance

Abstract

L. peruvianum var 'humifusum' is reproductively the most isolated of the species of the genusLycopersicon. It can be crossed with the cultivated tomato usingL. chilense as an intermediary. After a series of backcrosses of the three-genome hybrid F1 (L. esculentum ×L. chilense) ×L. peruvianum var 'humifusum' withL. esculentum, accompanied by selection for resistance to some economically important diseases, several lines were established. One of these lines, Cm 180, which showed resistance toClavibacter michiganensis subsp.michiganensis, was subjected to genetic analysis. This resistance was found to be controlled by a single dominant gene (Cm) that was not allelic to the gene originating fromL. hirsutum f.glabratum. ThisCm gene was genetically mapped on chromosome 4. The germ plasm ofL. peruvianum var 'humifusum' in combination withL. chilense was transferred intoL. esculentum. Different breeding lines possessing resistance to various diseases and pests could be developed from this material.

Development of an in vitro protocol to screen Clavibacter michiganensis subsp. michiganensis pathogenicity in different Solanum species

“…No commercial tomato varieties are known that prevent Cmm symptoms, even though related wild crossable relatives have been identified without symptoms after infection with Cmm. Examples are Solanum pimpinellifolium (Thyr, ; Sen et al ., ), Solanum habrochaites (Vulkova & Sotirova, ; Francis et al ., ), S. lycopersicum (Elenkov, ) and Solanum arcanum (Lindhout & Purimahua, ; Vulkova & Sotirova, ). To broaden the genetic variation of cultivated varieties, parts of the genome of wild tomatoes can be introgressed (Haggard et al ., ).…”

Different approaches of combating bacterial canker in tomato: in pursuit of resistance

“…Screening tomato wild relatives for enhancing Cmm resistance/ tolerance has been going on since the 1930's (Cardon 1934) and incorporating the wild relatives in tomato breeding has been tried (Elenkov 1965). Tolerance was found in lines after crossing with S. pimpinellifolium (Elenkov 1965;Thyr 1968;Jong and Honma 1976;Thyr 1976;Sen et al 2013), S. habrochaites (Hassan et al 1968;Vulkova and Sotirova 1993;Sotirova et al 1994;Francis et al 2001;Kabelka et al 2002), and S. arcanum (Lindhout and Purimahua 1987;Vulkova and Sotirova 1993;Sandbrink et al 1995;van Heusden et al 1999). Inheritance of tolerance in some of the wild relatives is complex and may be controlled by several genes as seen in the F2 population between the cultivated tomato and S. arcanum LA2157 (van Heusden et al 1999;Sen et al 2015).…”

“…Several studies have been done to understand the nature of tolerance in tomato against Cmm and different types of interactions were found: additive (van Heusden et al 1999;Coaker andFrancis 2004), polygenic (Thyr 1972), incomplete dominance (Thyr 1976) and dominant (Vulkova and Sotirova 1993). For our group, we aimed for resistance and in principle now that we found out that the bacterial density is still high in the symptomless plants, tolerance instead of resistance is a better term to use.…”

“…No commercial tomato varieties are known that prevent Cmm symptoms even though related wild crossable relatives have been identified without symptoms after infection with Cmm. Examples are S. pimpinellifolium (Thyr 1976;Sen et al 2013), S. habrochaites (Vulkova and Sotirova 1993;Francis et al 2001), S. lycopersicum (Elenkov 1965) and S. arcanum (Lindhout and Purimahua 1987;Vulkova and Sotirova 1993). To broaden the genetic variation of cultivated varieties parts of the genome of wild tomatoes can be introgressed (Haggard et al 2015).…”

“…Differences in tolerance were found between individual plants in offspring populations of several crosses between wild tomato species and cultivated tomato. Examples of these wild species are: S. pimpinellifolium (Elenkov 1965;Thyr 1968;Jong and Honma 1976;Thyr 1976;Sen et al 2013), S. habrochaites (Hassan et al 1968;Vulkova and Sotirova 1993;Sotirova et al 1994;Francis et al 2001;Kabelka et al 2002), and S. arcanum (Lindhout and Purimahua 1987;Vulkova and Sotirova 1993;Sandbrink et al 1995;van Heusden et al 1999). Resistance due to a substantially lower bacterial titre has not yet been found in the wild relatives.…”