Project description:Pistachio is a sustainable nut crop with exceptional climate resilience and nutritional value. To advance pistachios as a future food source and establish a model system for hard-shelled fruits, we generated essential knowledge and resources for the scientific community. We include a new chromosome-scale reference genome assembly and annotation of the most widely grown pistachio cultivar (Pistacia vera ‘Kerman’) and a spatiotemporal developmental study of the hull, shell, and kernel. Our study defined four distinct stages of pistachio growth and maturation by integrating tissue-level physiological and molecular data from thousands of nuts across twenty-four time points over three growing seasons. Transcriptional and metabolic changes in the kernel elucidate nutritional quality, such as the accumulation of unsaturated fatty acids, vital for shelf life and dietary value. This work yields new knowledge that will inform other woody crops and facilitate further improvement of pistachio as a globally significant, sustainable, and nutritious crop.