Gina Rodriguez

Bio: Gina Rodriguez is an academic researcher from Simon Fraser University. The author has contributed to research in topics: Ripening & Botrytis cinerea. The author has an hindex of 5, co-authored 5 publications receiving 71 citations.

Fusarium and Pythium species infecting roots of hydroponically grown marijuana (Cannabis sativa L.) plants

Abstract: An increase in the cultivation of Cannabis sativa (cannabis or marijuana) plants in Canada is becoming associated with increased incidence and severity of various diseases, many of which have not b...

Assessing Genetic Diversity in Cannabis sativa Using Molecular Approaches

Abstract: Cannabis sativa L represents plants cultivated for their psychoactive and medicinal properties (marijuana) or as a source of fibre, seed and oil (hemp) Breeding and selection efforts have produced marijuana genotypes (strains) with a range of levels of the cannabinoid Δ9-tetrahydrocannabinolic acid (THCA) and other non-psychoactive cannabinoids, eg cannabidiolic acid (CBDA) Hemp lines have been bred for high fibre content and seed production and have low/no THCA There are currently hundreds of marijuana strains which differ in THCA:CBDA ratios, growth characteristics, morphological features, THCA and CBDA contents, disease resistance, as well as overall medicinal value The extent of genetic diversity among these marijuana strains, as well as between marijuana and hemp, has been studied using a range of molecular approaches The results from these studies have demonstrated that considerable genetic diversity exists among marijuana as well as hemp strains Using ISSR markers, we have shown that distinct DNA banding patterns can allow for the initial discrimination between many of the strains tested, and provide an insight into the possible genetic relationships among strains Some strains, eg ‘Jack’, ‘Super Sour Skunk’, ‘Jilly Bean’, exhibited unique patterns that can be used to develop strain-specific DNA fingerprints In addition, a number of “landraces” and strains originating from remote geographic locations, showed unique and distinct ISSR patterns and morphologies A very high degree of genetic diversity was exhibited among the strains studied Additional molecular studies, including DNA sequencing approaches, should provide more insight into the genetic relationships that exist within strains of a complex plant species and could augment future breeding efforts for genetic improvement of C sativa

Root infection of wasabi (Wasabia japonica) by Pythium species

Abstract: Wasabi (Wasabia japonica) is cultivated under cool, humid conditions in many regions of the world for its rhizome, which is used as a culinary ingredient. In British Columbia, there is some wasabi production under semihydroponic conditions in polyethylene greenhouses. In January 2004, wasabi plants with browning and root loss, with no apparent foliar symptoms, were obtained. Pythium dissotocum and Pythium intermedium were consistently isolated from the affected roots. Wasabi plants produced from meristem-tip tissue culture were grown hydroponically in Gamborg's B5 nutrient solution at 18 °C for 6 months, inoculated with mycelial plugs of each Pythium sp., and incubated at 20 °C. After 2 months, the inoculated plants had significant root browning and loss, and the root dry mass of inoculated plants was reduced to 16% of that in the noninoculated controls. Both Pythium spp. were observed colonizing the roots and were recovered from inoculated plants. Pythium dissotocum and P. intermedium appear to be preval...

Role of fruit surface mycoflora, wounding and storage conditions on post-harvest disease development on greenhouse tomatoes

Abstract: Fungi causing post-harvest decay of greenhouse-grown tomato fruits in British Columbia were recovered from diseased samples collected during 2010 and 2011. The most frequently isolated fungi were Penicillium olsonii, Botrytis cinerea, Rhizopus stolonifer and Alternaria alternata, and to a lesser extent Galactomyces geotrichum. Pathogenicity tests showed that R. stolonifer caused the greatest fruit decay, followed by P. olsonii. The remaining fungi also caused some fruit rot, and lesion development by all fungi was enhanced by wounding of the fruits. A post-inoculation incubation temperature of 21°C promoted much greater disease development compared with 13°C. To assess the composition of the mycoflora on the surface of ripening tomato fruits, swab samples were collected weekly over a 6–18 week period from two commercial greenhouses during 2011 and 2012 and streaked onto potato dextrose agar. The most commonly recovered fungi from the fruit surfaces were species of Penicillium, Cladosporium, Asperg...

Disease management of tomato through PGPB: current trends and future perspective

Abstract: Tomato is the world's second most cultivated vegetable. During cultivation or post-harvest storage, it is susceptible to more than 200 diseases caused by an array of pathogenic fungi, nematodes, bacteria, and viruses. Although wide range of chemical pesticides are currently available to manage plant diseases, continuous application of pesticides not only affect the nutritional contents of tomato but also the texture or productivity of soil. In this context, plant growth promoting bacteria (PGPB) are one of the nature friendly, safe, and effective alternatives for the management of diseases and pathogens of tomato. Currently, numbers of microbes have been used as soil or plant inoculants in different plants including tomato as biocontrol. Besides disease inhibition, these inoculants also act as growth modulators. The present article describes the biocontrol potential of PGPB strains and mechanisms for the diseases management in tomato.

Gene Networks Underlying Cannabinoid and Terpenoid Accumulation in Cannabis

Abstract: Glandular trichomes are specialized anatomical structures that accumulate secretions with important biological roles in plant-environment interactions. These secretions also have commercial uses in the flavor, fragrance, and pharmaceutical industries. The capitate-stalked glandular trichomes of Cannabis sativa (cannabis), situated on the surfaces of the bracts of the female flowers, are the primary site for the biosynthesis and storage of resins rich in cannabinoids and terpenoids. In this study, we profiled nine commercial cannabis strains with purportedly different attributes, such as taste, color, smell, and genetic origin. Glandular trichomes were isolated from each of these strains, and cell type-specific transcriptome data sets were acquired. Cannabinoids and terpenoids were quantified in flower buds. Statistical analyses indicated that these data sets enable the high-resolution differentiation of strains by providing complementary information. Integrative analyses revealed a coexpression network of genes involved in the biosynthesis of both cannabinoids and terpenoids from imported precursors. Terpene synthase genes involved in the biosynthesis of the major monoterpenes and sesquiterpenes routinely assayed by cannabis testing laboratories were identified and functionally evaluated. In addition to cloning variants of previously characterized genes, specifically CsTPS14CT [(−)-limonene synthase] and CsTPS15CT (β-myrcene synthase), we functionally evaluated genes that encode enzymes with activities not previously described in cannabis, namely CsTPS18VF and CsTPS19BL (nerolidol/linalool synthases), CsTPS16CC (germacrene B synthase), and CsTPS20CT (hedycaryol synthase). This study lays the groundwork for developing a better understanding of the complex chemistry and biochemistry underlying resin accumulation across commercial cannabis strains.

Bacillus Spp.: Efficient Biotic Strategy to Control Postharvest Diseases of Fruits and Vegetables

Abstract: Postharvest diseases significantly reduce the shelf-life of harvested fruits/vegetables worldwide. Bacillus spp. are considered to be an eco-friendly and bio-safe alternative to traditional chemical fungicides/bactericides due to their intrinsic ability to induce native anti-stress pathways in plants. This review compiles information from multiple scientific databases (Scopus, ScienceDirect, GoogleScholar, ResearchGate, etc.) using the keywords “postharvest diseases”, “Bacillus”, “Bacillus subtilis”, “biocontrol”, “storage”, “losses”, and “fruits/vegetables”. To date, numerous examples of successful Bacillus spp. application in controlling various postharvest-emerged pathogens of different fruits/vegetables during handling, transportation, and storage have been described in the literature. The mechanism/s of such action is/are still largely unknown; however, it is suggested that they include: i) competition for space/nutrients with pathogens; ii) production of various bio-active substances with antibiotic activity and cell wall-degrading compounds; and iii) induction of systemic resistance. With that, Bacillus efficiency may depend on various factors including strain characteristics (epiphytes or endophytes), application methods (before or after harvest/storage), type of pathogens/hosts, etc. Endophytic B. subtilis-based products can be more effective because they colonize internal plant tissues and are less dependent on external environmental factors while protecting cells inside. Nevertheless, the mechanism/s of Bacillus action on harvested fruits/vegetables is largely unknown and requires further detailed investigations to fully realize their potential in agricultural/food industries.

Pathogens and Molds Affecting Production and Quality of Cannabis sativa L.

Abstract: Plant pathogens infecting marijuana (Cannabis sativa L.) plants reduce growth of the crop by affecting the roots, crown and foliage. In addition, fungi (molds) that colonize the inflorescences (buds) during development or after harvest, and which colonize internal tissues as endophytes, can reduce product quality. The pathogens and molds that affect C. sativa grown hydroponically indoors (in environmentally controlled growth rooms and greenhouses) and field-grown plants were studied over multiple years of sampling. A PCR-based assay using primers for the internal transcribed spacer region (ITS) of ribosomal DNA confirmed identity of the cultures. Root-infecting pathogens included Fusarium oxysporum, F. solani, F. brachygibbosum, Pythium dissotocum, P. myriotylum and P. aphanidermatum, which caused root browning, discoloration of the crown and pith tissues, stunting and yellowing of plants, and in some instances, plant death. On the foliage, powdery mildew, caused by Golovinomyces cichoracearum, was the major pathogen observed. On inflorescences, penicillium bud rot (caused by P. olsonii and P. copticola), botrytis bud rot (B. cinerea) and fusarium bud rot (F. solani, F. oxysporum) were present to varying extents. Endophytic fungi present in crown, stem and petiole tissues included soil-colonizing and cellulolytic fungi, such as species of Chaetomium, Trametes, Trichoderma, Penicillium and Fusarium. Analysis of air samples in indoor growing environments revealed that species of Penicillium, Cladosporium, Aspergillus, Fusarium, Beauvaria, and Trichoderma were present. The latter two species were the result of the application of biocontrol products for control of insects and diseases, respectively. Fungal communities present in unpasteurized coconut fibre (coco) growing medium are potential sources of mold contamination on cannabis plants. Swabs taken from greenhouse-grown and indoor buds pre- and post-harvest revealed the presence of Cladosporium and up to five species of Penicillium, as well as low levels of Alternaria species. Mechanical trimming of buds caused an increase in the frequency of Penicilllium species, presumably by providing entry points through wounds or spreading endophytes from pith tissues. Aerial distribution of pathogen inoculum and mold spores and dissemination through vegetative propagation, are important methods of spread, and entry through wound sites on roots, stems and bud tissues facilitates pathogen establishment on cannabis plants.