Elucidation of the biochemical pathways involved in two distinct cut-surface discolouration phenotypes of lettuce

To understand better the biochemistry and underlying genetic control of postharvest discolouration in lettuce, an F7 recombinant inbred population (Saladin x Iceberg) was grown field trials phenotyped. We identified two distinct phenotypes, pinking browning, which were negatively correlated at phenotypic level located six QTL associated with five browning plus total could not be attributed to either type, on improved map. Candidate genes investigated. Plants showing extremes also under controlled environment conditions. Lines extreme phenotypes from both environments used for transcriptome profiling differentially expressed transcripts identified. Involvement phenylpropanoid, flavonoid terpenoid biosynthesis pathways indicated development discolouration, point divergence different localised phenylpropanoid pathway. Other including amino acid metabolism implicated environmental factors temperature, water availability physical stress as potential contributory factors. Differential transcriptional may involved regulating potentially through stereochemical selection.