Sources of high soluble solid and vitamin C content from Lycopersicon pimpinellifolium are interesting in breeding for internal quality of fresh   market tomato Roselló, S . , Galiana - Balaguer, L . and Nuez, F . Biotechnology Dept . Universidad Politécnica de Valencia (UPV) . Cno . Vera, 14;   46022 Valencia . Spain Currently, improvement for internal quality (nutritive and organoleptic) is one of the main breeding objectives for fresh market tomato . Flavour and nutritive value are complex characteristics because they are conditioned by the content of many chemical compounds of tomato fruits . The precise analytical determination of each of these compounds could become a very laborious task . However, a preliminary screening trial can be performed to determine, by quick analyses, the main groups of compounds responsible for internal quality in tomato . It would permit the preselection interesting accessions and it would greatly reduce the number of detailed subsequent characterizations with more precise techniques . Screening L . pimpinellifolium germplasm for soluble solids content (SSC), titratable acidity and vitamin C content is the objective of this work . Twenty accessions of L . pimpinellifolium collected in Ecuador and Peru by the Vegetable Genetics Breeding Group (Politechnic University of Valencia) were tested (Table 1) . Three experimental breeding lines of tomato (FLA7060, NEMA - R and NE - 1), two Spanish varieties of processing tomato (GEVORA and GUADAJIRA) and one commercial hybrid (CAMBRIA, Seminis Vegetable Seeds, Almería, Spain) were used as controls . Plants were cultivated in the greenhouse during spring . Fruits were collected at the completely mature stage . SSC was determined with a refractometer (ATAGO - N1 Tokyo, Japan) and the results are reported as ºBrix at 20 ºC . Vitamin C content and titratable acidity were determined immediately after blending and made from aliquots of the homogenized sample . Vitamin C content was titrated with 2,6 dichloroindo - phenol . Total acidity was titrated with 0 . 1 N NaOH and phenoftalein (AOAC, 1990) . Screened accessions have shown a wide range of variation for SSC and vitamin C (Table 1) . The range of variation for titratable acidity was smaller . The most interesting accessions were UPV - 17039, UPV - 16978, UPV - 16984, UPV - 16982 and UPV - 16985 because their SSC was twice the value of the controls and sometimes more . The ratio SSC/Titratable acidity seems to suggest that the taste of UPV - 17039, UPV - 16984 and UPV - 16985 is slightly sweeter than that of the controls, while UPV - 16978 and UPV - 16982 have approximately the same taste as the