Breeding for resistance to tomato mosaic virus (ToMV) in pepino (Solanum muricatum Aiton)

Pepino is an Andean crop grown by its fruits and in the last decades it has started to be known outside its origin region. Its success as exotic dessert is of interest in European and Eastern markets, however, it is necessary to obtain varieties adapted to the crop area and use the most suitable techniques to produce quality fruits that satisfy the current demanding consumer.; One of the most worrying problems of pepino in our area are the diseases caused by virus, due mainly that pepino is vegetatively propagated. These diseases reduce yield and damage fruits, making them unmarketable. Tomato mosaic virus (ToMV) is one of the most dangerous diseases in this crop. Cultural practices are not effective and it is important to get resistant varieties. In this work a screening among cultivated species and related species has been done and the utility of resistant clones found in previous works is checked.; Resistant accessions are characterized at different temperature range and with different type of inoculum and it is observed the movement pattern at long and short distance. Resistant clones limit the movement of the virus at low and medium temperatures, meanwhile at high temperatures they behave as sensible accessions. These clones can be used in a breeding program, but previously it is necessary to know the genetic base of the resistance. Crosses between susceptible and resistant clones were made, and also between resistant clones, and they have been characterized against ToMV infection. Results show a possible monogenic resistance and different one between the resistant clones tested, which would be easier to add in the same material and make the resistance more durable. Another point of view to obtain resistant varieties is through transgenic plants resistant to ToMV. An in vitro regeneration protocol is needed, and it could be useful to micropropagate and maintain a great number of varieties and material in good and healthy conditions. An efficient protocol of regeneration of two varieties has been developed.