A comprehensive, chromosome-scale reference genome has been successfully generated for ‘Kerman,’ the predominant pistachio cultivar, by investigators at the University of California, Davis.
Pistachio (Pistacia vera) is a sustainable nut crop with exceptional climate resilience and nutritional value. Image credit: NoName_13.
Pistacia vera, commonly referred to as pistachio, is classified within the Anacardiaceae family, which also encompasses cashew and mango. It stands as the sole species in the Pistacia genus cultivated for its edible fruit.
While colloquially known as nuts, pistachio fruits are, in botanical terms, dehiscent drupes. These fruits are composed of three primary structural components: an outer leathery hull (exo-mesocarp), a hard, stony shell (endocarp), and the edible kernel (seed).
Pistachios are a valuable source of monounsaturated and polyunsaturated fatty acids, as well as potent antioxidants and essential vitamins.
Considering the remarkable resilience of pistachio trees to environmental stressors, particularly drought and salinity, they are poised to become a pivotal source of sustainable nourishment in the context of escalating climate change over the coming century. Indeed, global pistachio output has more than doubled within the last two decades.
“Previous efforts involved sequencing pistachio DNA, but this new genetic map presents a significantly enhanced level of detail and precision,” stated Dr. J. Grey Monroe, a researcher affiliated with the University of California, Davis.
“The advancement in the accuracy of this novel reference genome represents a leap comparable to transitioning from a rudimentary hand-drawn map to a high-resolution satellite image from Google Earth.”
Furthermore, the research team delineated four critical phases of nut development, from the floral stage through to maturity at harvest, offering a comprehensive physiological characterization that includes the hardening of the shell and the development of the kernel.
“Understanding the developmental trajectory of the nut will empower agriculturalists to make more informed management decisions, such as optimizing irrigation schedules, thereby fostering more sustainable pistachio cultivation,” commented Dr. Bárbara Blanco-Ulate, also from the University of California, Davis.
“A more refined understanding of its developmental processes could also equip growers with superior strategies for harvesting and aid in mitigating issues like insect infestations and fungal diseases.
“It was imperative to meticulously document not only the macroscopic alterations in pistachios but also the underlying genetic and molecular mechanisms driving these characteristics.”
“The generated genomic sequence provides groundbreaking insights into the differential gene expression patterns observed in nuts throughout the growing season.”
The investigators further pinpointed specific genes and biological pathways that contribute to the nutritional profile of pistachios.
This includes elucidating the mechanisms governing the accumulation of proteins and unsaturated fatty acids, which are instrumental for both product longevity and their health-promoting attributes.
“We are acquiring critical information on how pistachios acquire these nutritional qualities and how we might enhance them through improved cultivation practices,” Dr. Blanco-Ulate remarked.
These groundbreaking findings have been disseminated in the esteemed journal New Phytologist.
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Jaclyn A. Adaskaveg et al. In a nutshell: pistachio genome and kernel development. New Phytologist, published online March 19, 2025; doi: 10.1111/nph.70060
