SummaryMi-1.2 gene contributes to the resistance of tomato plants against some species of herbivores (i.e. nematodes, aphids) that are sap-feeders. In this study, two genotypes of tomato (Solanum lycopersicum L. syn. Lycopersicon esculentum Mill.) plants with dominant (Motelle cv) and recessive (Moneymaker cv) Mi-1.2 alleles were evaluated as a host-plant to the two-spotted spider mite (Tetranychus urticae Koch, Acari: Tetranychidae). Plants were grown under glasshouse conditions. The effect of tomato genotypes on T. urticae bionomy was estimated on cut leaflets in controlled photoperiod, temperature and humidity (L/D=16/8 h; D/N temp.=23/20°C; RH=70%). Results of laboratory evaluation showed that both the bionomy and population parameters of T. urticae reached a very similar or even higher value on plants with dominant Mi-1.2 allele than on plants with recessive one. A relatively high value of T. urticae parameters on plants resistant to root knot nematodes indicates that the mite has potential to develop rapidly. This allows the mite population to reach the density causing marked damage to plant in a short time. It is concluded that the presence of Mi-1.2 gene product in tomato plants does not significantly affect the reproductive potential of T. urticae. Therefore, Mi-1.2 gene cannot be a satisfying source of plant resistance to this mite-herbivore generalist.
Abstract:It is well known that the presence of the Mi-1.2 gene determines the resistance of tomato plants (Solanum lycopersicum L.) to 3 root-knot nematode species and some insect herbivores of the order Hemiptera. In this study, the density and dispersal of two-spotted spider mites (Tetranychus urticae) on tomato plants of 4 cultivars were evaluated under greenhouse conditions, to find out whether tomatoes differing in allelic combination of the Mi-1.2 gene exhibit similar or different resistance to the mite pest. The results show, for the first time, that the same initial number of mites develops into populations that vary in abundance and distribution depending on tomato allelic composition of the Mi-1.2 gene. The results indicate that the mite-pest develops more slowly on tomato plants of cultivar 'Motelle', carrying 2 dominant alleles for the Mi-1.2 gene, than on heterozygous 'Altess F1' tomatoes and both cultivars carrying only recessive alleles of this gene: 'Moneymaker' and 'Plaisence F1'. This suggests that the Mi-1.2 gene may be involved in tomato resistance against spider mites when this dominant gene is expressed homozygously, but this needs to be verified by further research.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.