Yield and Quality Characteristics of Lettuce Lines Developed by Mutation Breeding

In this study, we aimed to create genetic variation through physical mutagen application to lettuce (Lactuca sativa var. longifolia), a vegetable species whose leaves are consumed fresh, to obtain new varieties rich in nutritional content that can create market demand from this gene pool. Cervantes and Escule lettuce seeds were irradiated with effective mutation doses determined specific to the variety using a Cobalt-60 gamma ray source. Selection and inbreeding studies were performed for 4 generations, and 36 mutant lines were selected from the lines at the M4 stage to be used in subsequent experiments. Height, diameter, weight, leaf color, water-soluble dry matter (WSDM), chlorophyll, total carotenoid, vitamin C, lutein and total phenolic content of lettuce heads were examined in 36 mutant lines selected and in 4 commercial control varieties. The differences between the data obtained were statistically significant. Mutant lines numbered 62, 66, 71, 72, 74, 77, 84, and 100 which were found to be superior in terms of both morphological characteristics and nutritional content, were selected for inclusion in yield trials as a variety of candidates. These findings represent a significant step in increasing genetic diversity in agricultural production and developing lettuce varieties with higher yield and nutritional value.