Hemp (Cannabis sativa L.) has recently become an important crop due to the growing market demands for products containing cannabinoids. Unintended cross-pollination of C. sativa crops is one of the most important threats to cannabinoid production and has been shown to reduce cannabinoid yield. Ploidy manipulation has been used in other crops to improve agronomic traits and reduce fertility; however, little is known about the performance of C. sativa polyploids. In this study, colchicine was applied to two proprietary, inbred diploid C. sativa inbred lines, ‘TS1-3’ and ‘P163’, to produce the tetraploids ‘TS1-3 (4x)’ and ‘P163 (4x)’. The diploid, triploid, and tetraploid F1 hybrids from ‘TS1-3’ × ‘P163’, ‘TS1-3 (4x)’ × ‘P163’, and ‘TS1-3 (4x)’ × ‘P163 (4x)’ were produced to test their fertilities, crossing compatibilities, and yields. The results indicated a reduction in fertility in the triploids and the tetraploids, relative to their diploid counterparts. When triploids were used as females, seed yields were less than 2% compared to when diploids were used as females; thus, triploids were determined to be female infertile. The triploids resulting from the crosses made herein displayed increases in biomass and inflorescence weight compared to the diploids created from the same parents in a field setting. Statistical increases in cannabinoid concentrations were not observed. Lastly, asymmetric crossing compatibility was observed between the diploids and the tetraploids of the genotypes tested. The results demonstrate the potential benefits of triploid C. sativa cultivars in commercial agriculture.

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The regulation of cannabinoid synthesis in Cannabis sativa is of increasing research interest as restrictions around the globe loosen to allow the plant’s legal cultivation. Of the major cannabinoids, the regulation of cannabigerolic acid (CBGA) production is the least understood. The purpose of this study was to elucidate the inheritance of CBGA dominance in C. sativa and describe a marker related to this chemotype. We produced two crossing populations, one between a CBGA dominant cultivar and a tetrahydrocannabinolic acid (THCA) dominant cultivar, and one between a CBGA dominant cultivar and a cannabidiolic acid (CBDA) cultivar. Chemical and genotyping analyses confirmed that CBGA dominance is inherited as a single recessive gene, potentially governed by a non-functioning allelic variant of the THCA synthase. The “null” THCAS synthase contains a single nucleotide polymorphism (SNP) that may render the synthase unable to convert CBGA to THCA leading to the accumulation of CBGA. This SNP can be reliably used as a molecular marker for CBGA dominance in the selection and breeding of C. sativa.

We describe the use of high-fidelity single molecule sequencing to assemble the genome of the psychoactive Psilocybe cubensis mushroom. The genome is 46.6Mb, 46% GC, and in 32 contigs with an N50 of 3.3Mb. The BUSCO completeness scores are 97.6% with 1.2% duplicates. The Psilocybin synthesis cluster exists in a single 3.2Mb contig. The dataset is available from NCBI BioProject with accessions PRJNA687911 and PRJNA700437.

Hemp (Cannabis sativaL.) is a primarily short-day crop grown for grain, fiber, and secondary metabolites. Although terminal flowering of most non-domesticated hemp is regarded as photoperiod sensitive, limited germplasm is available for the development of day-neutral hemp. Day-neutral plants experience flower maturation independently of the short-day photoperiod cue which is typically triggered by photoperiods of less than 14 hours. The day-neutral trait is the subject of increased commercial interest for the purpose of breeding varieties with accelerated flowering time or cultivars that do not require labor- and cost-intensive light deprivation production systems. Genetic markers for the photoperiodic response would help breeders make early selection in the design of suitable cultivars for specific environments and cultivation calendars. Limited refereed information has been produced regarding the genetic regulation of photoperiodism inC. sativa. A population of 318 F2 individuals segregating for day-neutral flowering was developed, phenotyped, and genotyped. Genome-wide association analysis identified markers associated with the day-neutral trait indicating that a single recessive gene controlling photoperiod sensitivity is located within a large region of Chromosome 1. Flanking region sequence data of linked SNP markers was used in the development and validation of a TaqMan-based qPCR assay for the day-neutral trait. A genetic linkage map was produced, and QTL mapping identified two additional markers on Chromosome 1. Candidate genes,TARGET OF EARLY ACTIVATION TAGGED (TOE)/APETALA2 (AP2), andPSEUDO-RESPONSE REGULATOR 3 (PRR3), may work together to impact phase transition and photoperiodic flowering respectively and have key domains that are disrupted in day-neutral plants.