[ca] L'enciam (Lactuca sativa L.) es una hortalissa que tant el seu consum com la seva produccio esta estesa per tot el mon. A Catalunya ocupa el quart lloc en el cultiu d'hortalisses. Te el seu origen a la zona mediterrania i des dels seus inicis ha experimentat una gran evolucio i expansio. El continu progres a traves de la seleccio ha donat com resultat una gran diversitat que es veu representada tant en les varietats tradicionals o autoctones com en les varietats millorades. Aquest treball te com a objectiu realitzar un estudi d'una col·leccio de 23 varietats d'enciams tradicionals i millorades durant un cicle de primavera. Per a aixo s'han avaluat caracters morfologics i agronomics. Finalment, s'ha realitzat l'estudi de la conservacio post-collita. Aquest estudi preten a mes veure en quina mesura aquests caracters difereixen en funcio del tipus varietal (fulla de roure, meravella, llarg i trocadero) i l'origen (tradicional o millorat). A partir dels caracters morfologics seleccionats es va realitzar un Hierarchical cluster mapping, que va permetre confirmar la classificacio dels genotips en els 4 tipus varietals. Per als caracters agronomics i morfologics els genotips que van mostrar valors superiors en tots els caracters van ser LAC_16 seguit de LAC_15, a la vegada, les varietats tradicionals van presentar valors superiors a les millorades. La incidencia de pugo es va poder observar en tots els genotips, amb l'excepcio del LAC_22. Les varietats millorades van presentar un major contingut en materia seca que les varietats tradicionals. Els tipus varietals amb una mitjana superior de materia seca van ser tipus fulla de roure. L'avaluacio del color mitjancant el colorimetre va permetre establir diferencies per a aquest caracter entre genotips, aixi com, confirmar que el color de les fulles no es homogeni. L'avaluacio de la conservacio post-collita va mostrar que els enciams millorats tenien una perdua de pes major que els tradicionals. Finalment, el control visual va determinar que els tipus varietals que es van deteriorar abans van ser trocadero i fulla de roure.

[en] Lettuce (Lactuca sativa L.) is a vegetable whose production and consumption is widespread throughout the world. In Catalonia occupies the fourth place in the cultivation of vegetables. It has its origin in the Mediterranean area and since its inception it has experienced a great evolution and expansion. The continuous progress through selection process has resulted in a great diversity that is represented both in the traditional or native varieties and in the improved varieties. This end of degree project aims to conduct a study of a collection of 23 varieties of traditional and improved lettuce during a spring cycle. In order to do this, morphological and agronomic characters have been evaluated. Finally, a study of postharvest conservation has been carried out. This project also aims to see to what extent these characters differ depending on the varietal type (oak leaf, batavian, long and butterhead lettuce) and the origin (traditional or modern). From the selected morphological characters, a Hierarchical cluster mapping was carried out, which confirmed the classification of the genotypes in the 4 varietal types. For the agronomic and morphological characters, the genotypes that showed higher values in all the characters were LAC_16 followed by LAC_15, in turn, the traditional varieties presented higher values than the modern varieties. All genotypes showed aphid incidence, except for LAC_22. The modern varieties had a higher dry matter content than traditional varieties. The varietal types with a higher mean of dry matter were oak leaf. The evaluation of the color by means of the colorimeter allowed to establish differences for this character between genotypes, as well as, to confirm that the color of the leaves is not homogeneous. The evaluation of postharvest conservation showed that the modern lettuces had greater weight loss than the traditional ones. And in the visual control the varietal types that deteriorated before were butterhead lettuce and oak leaf.