Biology subjects

Henry, P.

Publications and source records attributed to Henry, P..

4 recordsLinked to original sources

bioRxiv2022

Sporodochia formed by Fusarium oxysporum f. sp. fragariae produce airborne conidia and are ubiquitous on diseased strawberry plants in California

Sporodochia are dense masses of fungal hyphae bearing asexual conidia. For Fusarium oxysporum, sporodochia are known to produce airborne conidia and enhance the dissemination of this otherwise soilborne pathogen. Sporodochia are small and transient, and they are documented for only a few formae speciales of Fusarium oxysporum. This study reports airborne conidia and sporodochia produced by F. oxysporum f. sp. fragariae, the cause of Fusarium wilt of strawberry, in the Monterey Bay region of California. Sporodochia were consistently present in Fusarium wilt-afflicted strawberry fields and were discovered in 21 of 24 Fusarium wilt-diseased fields. Only necrotic tissues were observed bearing sporodochia, and they were most frequently observed on petioles and peduncles. Sporodochia grew significantly longer up peduncles than petioles, extending further away from the base of the plant and toward parts of the canopy more exposed to wind. A stolon hosted the longest stretch of sporodochial growth, found covering the stolons entire 35 cm length and also the base of the daughter plant. Macroconidia were produced by all sporodochia samples, and we did not find microconidia on any samples. An initial series of experiments confirmed the potential for conidia produced by sporodochia to disperse with wind over short distances. The prevalence of sporodochia producing airborne spores of F. oxysporum f. sp. fragariae has great importance for disease management and biosecurity.

microbiology↗

bioRxiv2022

Host use does not drive genetic structure of mountain pine beetles in western North America

The mountain pine beetle (MPB) is one component of an intensively studied co-evolved host-pest system. We investigated the spatial genetic structure of MPB within its historic and recent geographic range expansion as it relates to host use in western North America using 13 pre-selected microsatellite loci. AMOVA shows that genetic structure is not correlated with the host tree species, arguing against the formation of host-race within this species. STRUCTURE analysis shows 4 main clusters in western North America: Northern - Northern British Columbia/Alberta; Central - Southern British Columbia/Alberta/Washington/Idaho/Montana; Southwest - Oregon/California/Nevada and; Southeast - Utah/Wyoming/Arizona/Colorado/South Dakota. Heterozygosity, allelic richness, and number of private alleles is greatest in the Southwest cluster. This cluster correlates with one of the three refugia hypothesized from a recent analysis of neo-Y haplotypes by Dowle and colleagues and represents an important reservoir of MPB genetic diversity.

genetics↗

bioRxiv2020

A Single Nucleotide Polymorphism assay sheds light on the extent and distribution of genetic diversity, population structure and functional basis of key traits in cultivated North American Cannabis

BackgroundThe taxonomic classification of the Cannabis genus has been delineated through three main types: sativa (long and less branched plant with long and narrow leaves), indica (short but highly branched plant with broader leaves) and ruderalis (wild type with short stature, less branching and small thick leaves). While still under discussion, particularly whether the genus is polytypic or monotypic, this broad classification reflects putative geographical origin of each group and putative chemotypic and pharmacology. MethodsHere we describe a thorough investigation of cannabis accessions using a set of 22 highly informative and polymorphic SNP markers associated with important traits such as cannabinoid and terpenoid expression as well as fibre and resin production. The assay offers insight into cannabis population structure, phylogenetic relationship, population genetics and correlation to secondary metabolite concentrations and demonstrate the utility of this assay for rapid, repeatable and cost-efficient genotyping of commercial and industrial cannabis accessions for use in product traceability, breeding programs, regulatory compliance and consumer education. ResultsThe main outcomes are the identification of 5 clusters in the sample set available, including industrial hemp, resin hemp which likely underwent a bottleneck to stabilize CBDA accumulation (Type II & III). THC resin (type I) make up the other three clusters with terpinolene (colloquial "sativa" or "NLD"), myrcene/pinene and myrcene/limonene (colloquial "indica", "BLD"), which also putatively harbour an active CBCAS. ConclusionThe functional basis of key traits is also discussed as recently enabled by the NCBI Cannabis sativa Annotation Release 100, allowing for hypothesis testing with regards to secondary metabolite production as well as other key traits of importance for adaptable and compliant large-scale seed production under the new US Domestic Hemp Production Program.

plant biology↗

bioRxiv2018

The genetic basis of the human-cannabis relationship

Cannabis can elicit various reactions in different consumers. In order to shed light on the mechanisms underlying the human-cannabis relationship, we begin to investigate the genetic basis of this differential response. The web-based platform OpenSNP was used to collect selfreported genetic and phenotypic data. Participants either reported a positively or negative affinity to cannabis. A total of 26 individuals were retained, 10 of which indicated several negative responses and the remaining 16 indicating strong affinity for Cannabis. A total of 325895 single nucleotide polymorphisms (SNPs) were retained. The software TASSEL 5 was used to run a genome-wide association study (GWAS), with a generalized liner model (GLM) and1000 permutations. The analysis yielded a set of 45 SNPs that were significantly associated with the reported affinity to cannabis, including one strong outlier found in the MYO16 gene. A diagnostic process is proposed by which individuals can be assessed for their affinity to cannabis. We believe this type of tool may be helpful in alleviating some of the stigma associated with cannabis use in individuals sensitive to THC and other cannabis constituents such as myrcene, which may potentiate negative responses.

animal behavior and cognition↗