scholarly journals First Report of ‘Candidatus Phytoplasma trifolii’ Related Strain Associated with Yellowing and Witches’-Broom of Industrial Hemp (Cannabis sativa) in Arizona

Plant Disease ◽  
2021 ◽  
Author(s):  
Jiahuai Hu
Keyword(s):  
Cannabis Sativa ◽  
Disease Incidence ◽  
Taqman Probe ◽  
Rrna Gene ◽  
Related Strain ◽  
Health Food ◽  
Taxonomic Assignment ◽  
First Report ◽  
Wide Range ◽  
Industrial Hemp

In Arizona, industrial hemp (Cannabis sativa) is a newly cultivated crop for fiber, oil, cosmetic products, and health food. During July to September 2020, two fields of industrial hemp crops were identified in southern Arizona with 10 to 30% incidence of plants showing witches’ broom. Disease incidence was assessed by counting symptomatic plants in 4 randomly selected rows of 25 plants in each field. Symptoms ranged from leaf mottling and yellowing on mildly affected plants to leaf curling and shortened internode length of stem on severely affected plants (Fig. 1). Shoots were randomly collected from eight symptomatic plants and three asymptomatic plants in the same area. Genomic DNA was extracted from 200 mg of each sample using DNeasy Plant Pro Kit (Qiagen Inc., Valencia, CA) according to the manufacturer’s instructions. Phytoplasma was tested by a real-time PCR assay and TaqMan probe targeting the 23S ribosomal RNA gene that detects a wide range of known Phytoplasmas (Hodgetts et al., 2009). Beet curly top virus (BCTV) was targeted using BCTV-specific primers BCTV1 and BCTV2 following a method by Rondon (Rondon et al., 2016). BCTV was not detected in the plants, but Phytoplasmas were detected in all eight symptomatic plants, but not in the three control plants. The positive DNA samples were used to identify the phytoplasma by nested PCR using universal phytoplasma-specific primer pairs P1/P6 (Deng, S. et al. 1991) and R16F2n/R16R2 (Gundersen et al., 1996) targeting the 16S rRNA gene and the resulting 1.25 kb fragment in 4 positive samples was subjected to Sanger sequencing (Eton Bioscience, San Diego). All 4 sequences were identical and deposited in GenBank under accession MW981356. BLASTn results indicated 100% identity with that of several ‘Candidatus Phytoplasma trifolii’ strains on potato (KR072666, KF178706) in Washington and chile peppers (HQ436488) in New Mexico. It also shared 99.84% identity with the sequence of the reference strain of Candidatus Phytoplasma trifolii’ (AY390261) that caused clover proliferation. The phytoplasma AZH1 was classified as a member of subgroup A within group16SrVI using iPhyClassifier, an interactive online tool for phytoplasma classification and taxonomic assignment (Zhao et al., 2013). Phylogenetic analysis revealed that the phytoplasma AZH1 clustered with other isolates of 'Candidatus Phytoplasma trifolii' (Fig. 2), including the strain NV1 associated with witches’ broom on C. sativa in Nevada (Feng et al. 2019). This is the first report of ‘Candidatus Phytoplasma trifolii’ related strain associated with yellowing and witches’ broom on hemp in Arizona. This finding is significant as the observation of symptoms at 30% incidence in one field suggested that the identified pathogen may pose a significant threat to the production of industrial hemp production in Arizona.

scholarly journals First Report of Beet Curly Top Virus Infecting Industrial Hemp (Cannabis sativa) in Arizona

Plant Disease ◽  
2020 ◽  
Author(s):  
Jiahuai Hu ◽  
Robert Masson ◽  
Laura Dickey
Keyword(s):  
Cannabis Sativa ◽  
Chili Pepper ◽  
First Report ◽  
Beet Curly Top Virus ◽  
Wide Range ◽  
Western Colorado ◽  
Dna Fragment ◽  
Chili Peppers ◽  
Industrial Hemp ◽  
Light Green

Industrial hemp (Cannabis sativa) is an emerging crop in Arizona, with many uses, including fiber, cosmetic products, and health food. In 2020, severe curly top disease outbreaks were observed in several hemp fields in Yuma and Graham Counties, Arizona, where disease incidence and severity were considerably high, up to 100% crop loss occurring in some fields. A wide range of symptoms have been observed at different infection stages and plant growth stages at the time of infection. Early stage symptoms manifest as light green-to-yellowing of new growth, similar to sulfur or micronutrient deficiency, usually combined with older leaves with dark green “blotchy” mosaic mottling overlaying light green chlorosis. Mosaic mottling of older leaves continues into mid-growth stage, and is coupled with more severe yellowing and witch’s broom (stunted leaves and shortened internode length of stem) of apical meristematic tissue. Curling and twisting of new leaves has also been observed. Symptoms often appear to be isolated to individual branches, with other branches showing no visual symptoms, often outgrowing and covering affected branches until harvest. Late stage symptoms include severe leaf curling with or without twisting, continued stunting, and necrosis of yellow leaves, resulting in significant yield reduction. Severely affected plants dwarfed by the virus experienced high mortality rates later into the season, most likely attributed to reduced ability to overcome abiotic stress conditions. These symptoms indicated the likelihood of curly top caused by Beet curly top virus (BCTV), which has been recently reported in Colorado (Giladi et al., 2020). Shoots were collected from thirty-eight symptomatic and nine asymptomatic hemp plants from July to August, 2020. Leaves were also collected as positive control from four chili pepper plants with or without curly top symptoms in Cochise County. Genomic DNA was extracted using DNeasy Plant Pro Kit (Qiagen Inc., Valencia, CA) according to the manufacturer’s instructions. BCTV-specific primers BCTV1 and BCTV2 were used to detect BCTV following a method by Rondon (Rondon et al., 2016). A 500 bp DNA fragment, indicative of BCTV, was amplified from all symptomatic hemp and chili pepper samples, but not from asymptomatic samples. Sequence analysis of this 500 bp DNA fragment revealed 98.99 % identity with GenBank accession MK803280, which is Beet curly top virus isolate from hemp identified in Western Colorado (Giladi et al., 2020). The full-length genomes of BCTV isolates from hemp and chili peppers were generated with additional primers 328F/945R (620bp), 455F/ 945R (490bp), OutR/ 2213F (1,190bp), 2609R/ 1278R (1,340bp), BCTV2/ 2609R (1,890bp) (Rondon et al., 2016, Strausbaugh et al., 2008). The complete nucleotide sequence (MW182244) from hemp was 2,929 bp and had 99.35% sequence identity with GenBank accession KX867055, which was a Worland strain of Beet curly top virus isolated from an Idaho sugar beet plant (Strausbaugh et al., 2017). Our hemp BCTV genome sequences shared 96.08% identity with the hemp strain of BCTV from Colorado (MK803280) and 99.50% identity with the BCTV isolate (MW188519) from chili pepper identified in this study. BCTV was reported on outdoor hemp in Western Colorado, in 2020 (Giladi et al., 2020). This is the first report of BCTV in Arizona causing curly top of industrial hemp in the field. In Arizona, BCTV is widespread on many agronomic crops including chili peppers and spread primarily by the phloem-feeding beet leafhoppers: Circulifer tenellus (Hemiptera: Cicadellidae) (Bennett, 1967). Due to the wide distribution of beet leafhoppers and abundant range of host plants for the virus, BCTV may become one of the most yield-limiting factors affecting the emerging industrial hemp production systems in Arizona.

scholarly journals First Report in Mali of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica

Plant Disease ◽  
2012 ◽  
Vol 96 (4) ◽  
pp. 581-581 ◽  
Author(s):  
O. Pruvost ◽  
C. Boyer ◽  
K. Vital ◽  
C. Verniere ◽  
L. Gagnevin ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Mangifera Indica ◽  
Negative Control ◽  
Tris Buffer ◽  
Control Treatment ◽  
Bacterial Canker ◽  
Xanthomonas Citri ◽  
First Report ◽  
Infection Pattern ◽  
Wide Range

Bacterial canker (or black spot) of mango caused by Xanthomonas citri pv. mangiferaeindicae is an important disease in tropical and subtropical areas (1). X. citri pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Severe leaf infection may result in abscission. Fruit symptoms appear as small, water-soaked spots on the lenticels that later become star shaped, erumpent, and exude an infectious gum. Often, a “tear stain” infection pattern is observed on the fruit. Severe fruit infections cause premature drop. Twig cankers are potential sources of inoculum and weaken branch resistance to winds. Yield loss up to 85% has been reported at grove scale for susceptible cultivars (1). Suspected leaf lesions of bacterial canker were collected in July 2010 from mango trees in four, six, and three localities of the Koulikoro, Sikasso, and Bougouni provinces of Mali, respectively (i.e., the major mango-growing areas in this country). Nonpigmented Xanthomonas-like colonies were isolated on KC semiselective medium (3). Twenty-two strains from Mali were identified as X. citri pv. mangiferaeindicae based on IS1595-ligation-mediated PCR (4) and they produced fingerprints fully identical to that of strains isolated from Ghana and Burkina Faso. Five Malian strains (LH409, LH410, LH414, LH415-3, and LH418) were compared by multilocus sequence analysis (MLSA) to the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae. This assay targeted the atpD, dnaK, efp, and gyrB genes, as described previously (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae whatever the gene assayed, but differed from any other assayed X. citri pathovar. Leaves of mango cv. Maison Rouge from the youngest vegetative flush were infiltrated (10 inoculation sites per leaf for three replicate leaves on different plants per bacterial strain) with the same five strains from Mali. Bacterial suspensions (~1 × 105 CFU/ml) were prepared in 10 mM Tris buffer (pH 7.2) from 16-h-old cultures on YPGA (7 g of yeast, 7 g of peptone, 7 g of glucose, and 18 g of agar/liter, pH 7.2). The negative control treatment consisted of three leaves infiltrated with sterile Tris buffer (10 sites per leaf). Plants were incubated in a growth chamber at 30 ± 1°C by day and 26 ± 1°C by night (12-h/12-h day/night cycle) at 80 ± 5% relative humidity. All leaves inoculated with the Malian strains showed typical symptoms of bacterial canker a week after inoculation. No lesions were recorded from the negative controls. One month after inoculation, mean X. citri pv. mangiferaeindicae population sizes ranging from 5 × 106 to 1 × 107 CFU/lesion were recovered from leaf lesions, typical of a compatible interaction (1). To our knowledge, this is the first report of the disease in Mali. Investigations from local growers suggest that the disease may have been present for some years in Mali but likely less than a decade. A high disease incidence and severity were observed, suggesting the suitability of environmental conditions in this region for the development of mango bacterial canker. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (4) O. Pruvost et al. Phytopathology 101:887, 2011.

scholarly journals First Report of New Bacterial Leaf Blight of Rice Caused by Pantoea ananatis in Southeast China

Plant Disease ◽  
2021 ◽  
Author(s):  
Lin Yu ◽  
Changdeng Yang ◽  
Zhijuan Ji ◽  
Yuxiang Zeng ◽  
Yan Liang ◽  
...  
Keyword(s):  
Oryza Sativa L ◽  
Sequence Similarity ◽  
Disease Incidence ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Bacterial Suspension ◽  
Rrna Gene ◽  
Pantoea Ananatis ◽  
Southeast China ◽  
First Report

In autumn 2020, leaf blight was observed on rice (Oryza sativa L., variety Zhongzao39, Yongyou9, Yongyou12, Yongyou15, Yongyou18, Yongyou1540, Zhongzheyou8, Jiafengyou2, Xiangliangyou900 and Jiyou351) in the fields of 17 towns in Zhejiang and Jiangxi Provinces, China. The disease incidence was 45%-60%. Initially, water-soaked, linear, light brown lesions emerged in the upper blades of the leaves, and then spread down to leaf margins, which ultimately caused leaf curling and blight during the booting-harvest stage (Fig. S1). The disease symptoms were assumed to be caused by Xanthomonas oryzae pv. oryzae (Xoo), the pathogen of rice bacterial blight. 63 isolates were obtained from the collected diseased leaves as previously described (Hou et al. 2020). All isolates showed circular, smooth-margined, yellow colonies when cultured on peptone sugar agar (PSA) medium for 24h at 28℃. The cells were all gram-negative and rod-shaped with three to six peritrichous flagella; positive for catalase, indole, glucose fermentation and citrate utilization, while negative for oxidase, alkaline, phenylalanine deaminase, urease, and nitrate reductase reactions. 16S rRNA gene sequence analysis from the 6 isolates (FY43, JH31, JH99, TZ20, TZ39 and TZ68) revealed that the amplified fragments shared 98% similarity with Pantoea ananatis type strain LMG 2665T (GenBank JFZU01) (Table S3). To further verify P. ananatis identity of these isolates, fragments of three housekeeping genes including gyrB, leuS and rpoB from the 6 isolates were amplified and sequenced, which showed highest homology to LMG 2665T with a sequence similarity of 95%-100% (Table S3). Primers (Brady et al. 2008) and GenBank accession numbers of gene sequences from the 6 isolates are listed in Table S1 and Table S2. Phylogenetic analysis of gyrB, leuS and rpoB concatenated sequences indicated that the 6 isolates were clustered in a stable branch with P. ananatis (Fig. S2). Based on the above morphological, physiological, biochemical and molecular data, the isolates are identified as P. ananatis. For pathogenicity tests, bacterial suspension at 108 CFU/mL was inoculated into flag leaves of rice (cv. Zhongzao39) at the late booting stage using clipping method. Water was used as a negative control. The clipped leaves displayed water-soaked lesions at 3 to 5 days after inoculation (DAI); then the lesion spread downward and turned light brown. At about 14 DAI, blight was shown with similar symptoms to those samples collected from the rice field of Zhejiang and Jiangxi provinces (Fig. S1). In contrast, the control plants remained healthy and symptomless. The same P. ananatis was re-isolated in the inoculated rice plants, fulfilling Koch’s postulates. In the past decade, P. ananatis has been reported to cause grain discoloration in Hangzhou, China (Yan et al. 2010) and induce leaf blight as a companion of Enterobacter asburiae in Sichuan province, China (Xue et al. 2020). Nevertheless, to the best of our knowledge, this is the first report of P. ananatis as the causative agent of rice leaf blight in southeast China. This study raises the alarm that the emerging rice bacterial leaf blight in southeast China might be caused by a new pathogen P. ananatis, instead of Xoo as traditionally assumed. Further, the differences of occurrence, spread and control between two rice bacterial leaf blight diseases caused by P. ananatis and Xoo, respectively need to be determined in the future.

scholarly journals First Report of Aster Yellow Phytoplasmas (‘Candidatus Phytoplasma asteris’) in Canadian Grapevines

Plant Disease ◽  
2009 ◽  
Vol 93 (6) ◽  
pp. 669-669 ◽  
Author(s):  
C. Y. Olivier ◽  
D. T. Lowery ◽  
L. W. Stobbs ◽  
C. Vincent ◽  
B. Galka ◽  
...  
Keyword(s):  
Prince Edward Island ◽  
Taqman Probe ◽  
First Report ◽  
Sequence Identity ◽  
Flower Abortion ◽  
Freeze Dried ◽  
Wide Range ◽  
Canadian Food Inspection Agency ◽  
Pcr Technology ◽  
Elm Yellows

In North America, elm yellows, aster yellows (AY), and X-disease phytoplasmas have been detected in American grapevines (1), and recently, Bois noir was detected in Canadian vineyards from British Columbia (BC) and Ontario (ON) (2). Typical symptoms of grapevine yellows (GY) include leaf rolling and chlorosis, uneven or total lack of lignification of canes, flower abortion or berry withering, and stunting. In 2006 and 2007, independent surveys were conducted by the Canadian Food Inspection Agency (CFIA) and Agriculture and Agri-Food Canada (AAFC) to detect phytoplasmas in Canadian vineyards containing different cultivars in BC, ON, Québec (QC), Nova Scotia, New Brunswick, and Prince Edward Island. The CFIA collected and tested 651 fresh leaf samples from recently imported grapevines and older grapevines in the same or neighboring blocks displaying symptoms typical of those associated with disease caused by phytoplasmas. Many vineyards were surveyed only once. AAFC collected and tested 3,485 samples from symptomatic and asymptomatic grapevines from established vineyards in ON, BC, and QC. The same vineyards were sampled in ON and BC both years; QC vineyards were only sampled in 2007. AAFC-collected leaf samples were freeze dried and stored at –20°C before processing. CFIA samples were tested by a modified real-time PCR assay and TaqMan probe targeting the 16S ribosomal RNA gene that detects a wide range of known phytoplasmas (2). Positive samples were confirmed by conventional PCR using the phytoplasma-specific primers P1/P7 (3) and the resulting ~1,800-bp fragment was cloned and sequenced as previously described (2). DNA extracted by AAFC was amplified by nested PCR technology with universal phytoplasma specific primer pairs P1/P6 and R16R2/R16F2 (3) and the resulting 1,200-bp fragment was cloned and sequenced. Two plants, one located in ON in 2006 and the other in BC in 2007, were found to be infected with an AY-like phytoplasma by the CFIA. The phytoplasmas detected in both infected plants had a 99.9% nt sequence identity with AY phytoplasma sequences from GenBank (Accession Nos. AF222063 and AY665676, respectively), with the BC isolate also showing 100% identity to a strain of AY, ash witches'-broom phytoplasma (GenBank Accession No. AY566302). AAFC detected phytoplasma DNA in both years in a total of 17 symptomatic plants and 21 asymptomatic plants from different vine varieties in ON, BC, and QC. Positive samples were found to have a 99.0% nt sequence identity to AY subgroup 16SrI-A (GenBank Accession No. AY180956). Sequences were exchanged for confirmation of phytoplasma identity and were deposited in Genbank under Accession Nos. FJ659844 and FJ824597. Phytoplasma strains were identified for all plants in which phytoplasmas were detected. Results show that AY is present in vineyards in the provinces of ON, BC, and QC. To our knowledge, this is the first report of AY being detected in grapevines in Canada. References: (1) E. Boudon-Padieu. Bull. O I V, 79:299, 2003. (2) M. Rott et al. Plant Dis. 91:1682, 2007. (3) E. Tanne et al. Phytopathology 91:741, 2001.

scholarly journals First Report of Fusarium falciforme (FSSC 3+4) Causing Rot of Industrial Hemp (Cannabis sativa) in California

Plant Disease ◽  
2021 ◽  
Author(s):  
Kelley Rose Paugh ◽  
Johanna Del Castillo Múnera ◽  
Cassandra L Swett
Keyword(s):  
Root Rot ◽  
Cannabis Sativa ◽  
Negative Control ◽  
Stem Rot ◽  
Tween 20 ◽  
Post Inoculation ◽  
First Report ◽  
Fusarium Falciforme ◽  
Stem Lesions ◽  
Industrial Hemp

Industrial hemp (Cannabis sativa) is a newly legal crop in California that is grown for cannabidiol oil, fiber and seed. In August 2019, whole plant decline and root rot were observed affecting <5% of plants in two industrial fields in Fresno County, CA. Symptoms included chlorotic, collapsed foliage, stem vascular discoloration, and root rot with abundant mycelial growth. Stem and root segments (1-2 cm) from three to five diseased plants were agitated in 0.1% tween-20 and soaked in 70% ethanol for 30 s and 1% NaOCl for 2 min. After incubating for 5 to 7 days on 1:10 potato dextrose agar (PDA) amended with tetracycline, Fusarium selective medium (FSM), and PARP (pimaricin + ampicillin + rifampicin + pentachloronitrobenzene [PCNB] agar) medium, white to pale cream aerial mycelium emerged from tissue of all plants on PDA and FSM but not PARP. Isolates cultured on 0.1% potassium chloride agar formed heads of microconidia on long monophialides consistent with the Fusarium solani species complex (FSSC) (Leslie and Summerell 2008). To obtain pure cultures of two isolates (CS529 and CS530), a single-hyphal tip was excised and grown on PDA. DNA was extracted from actively growing mycelium (PrepMan Ultra kit). The translation elongation factor gene (EF-1α) was amplified via PCR using EF1/EF2 primers (O’Donnell et al. 1998). Sequences of the two isolates were identical and deposited under accession number MW892973 in GenBank. The 599 bp sequence was 99.33% identical to FSSC 3 + 4 (Fusarium falciforme) accessions FD_01443_EF-1a based on FUSARIUM-ID BLAST analysis. To evaluate pathogenicity, stems of hemp plants (cv. ‘Berry Blossom’; n=8 plants per isolate) were wounded by penetrating the epidermis in an area about 0.5-cm square by 1-mm deep and 8-inches above the soil line. A 0.5 cm-diameter plug of 7-day old F. falciforme-colonized PDA was placed against the wound. Inoculation sites were loosely wrapped with parafilm for 2 days. A negative control consisted of a sterile PDA plug (n=3). Treatments were arranged in a completely randomized design in a greenhouse. The experiment was conducted once, due to regulatory restrictions at campus facilities. At 61 days post-inoculation, external stem lesions were significantly larger in diameter (P < 0.05; Tukey’s HSD) in plants inoculated with CS529 (8 ± 1 mm) compared to the control (2 ± 0 mm), and larger but not significant for CS530 (6 ± 1 mm). Internal stem lesions (i.e., rot in stele) were observed in plants inoculated with CS529 (9 ± 3 mm); stem rot was very minor in plants treated with CS530 (1 ± 1 mm) and nonexistent for control plants. No other disease symptoms were observed. F. falciforme was isolated from stems of CS529- and C530-inoculated plants. Sequences of re-isolates matched 100% with accession MW892973. These results suggest that F. falciforme causes rot in hemp in California. These studies specifically confirm stem rot abilities; field observations of root rot indicate root rotting abilities, but further tests are needed for confirmation. This is the first report of F. falciforme causing disease in industrial hemp. FSSC was described as causing foot rot in hemp in Italy (Sorrentino et al. 2019), but these isolates belonged to phylogenetic species 5 (F. solani) not F. falciforme. In addition, F. falciforme was reported as causing root rot in hydroponically grown cannabis (Punja and Rodriguez 2018). These studies provide the foundation for development of management tools for hemp disease.

scholarly journals First Report of Leek yellow stripe virus in Garlic in Ohio

Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 574-574 ◽  
Author(s):  
A. L. Testen ◽  
D. P. Mamiro ◽  
T. Meulia ◽  
N. Subedi ◽  
M. Islam ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Detection Methods ◽  
Small Scale ◽  
Rt Pcr ◽  
Asexual Propagation ◽  
First Report ◽  
Leek Yellow Stripe Virus ◽  
Wide Range ◽  
Virus Complex ◽  
Yellow Stripe

Leek yellow stripe virus (LYSV), genus Potyvirus, family Potyviridae, infects a wide range of Allium species worldwide. LYSV is one of several viruses that chronically infect garlic, Allium sativum L. The garlic virus complex, which includes LYSV, Onion yellow dwarf virus, and Garlic common latent virus, is perpetuated by asexual propagation (4) and is transmitted to clean planting material by aphids (3). This virus complex can reduce garlic bulb weight by nearly three quarters (2), and LYSV-only infections can result in approximately a one-quarter reduction in bulb weight (2). Garlic is grown as a small-scale, specialty crop in Ohio. During late May and early June 2013, garlic plants with virus-like symptoms were collected from Medina, Holmes, and Wayne counties, Ohio. Plants exhibited chlorotic streaking, foliar dieback, dwarfing, small bulbs, and cylindrical bulbs that failed to differentiate into cloves. Incidence of affected plants in the fields was up to 5% and all fields had early season aphid infestations. Flexuous rods were observed in TEM micrographs of plant sap from symptomatic leaves. Five symptomatic plants and six asymptomatic plants (from fields with symptomatic plants) were evaluated for LYSV by DAS-ELISA (Agdia, Inc., Elkhart, IN). Reverse transcriptase (RT)-PCR with LYSV-specific primers LYSV-WA and LYSV-WAR (3) was performed with cDNA generated by the High Capacity cDNA Reverse Transcription Kit (Applied Biosystems, Foster City, CA). Both foliar and bulb tissues were tested using both detection methods. Forty percent of symptomatic plants and 67% of asymptomatic plants tested positive for LYSV with both ELISA and RT-PCR. LYSV was detected in both foliar and bulb tissues, including both tissues from asymptomatic plants. Five PCR amplicons generated from both foliar and bulb tissue were sequenced and shown to share 96 to 98% maximum identity with an LYSV polyprotein gene accession in GenBank (AY842136). This provided additional support that the detected virus was LYSV. LYSV was initially difficult to detect in Ohio fields due to low disease incidence and subtle symptom development. Use of virus-tested garlic bulbs can improve yield for several years, even following viral reinfection by aphids, compared to growing garlic from chronically infected bulbs (1). However, many growers routinely save bulbs from year to year and lack access to or knowledge of virus-tested sources of garlic bulbs. Conducive conditions, chronic infections, or co-infections with other viruses enhance the severity of symptoms and yield loss (2). LYSV has previously been reported in garlic producing regions of the northwestern United States (3), and to our knowledge, this is the first report of LYSV in garlic in Ohio. References: (1) V. Conci et al. Plant Dis. 87:1411, 2003. (2) P. Lunello et al. Plant Dis. 91:153, 2008. (3) H. Pappu et al. Plant Health Progress 10, 2008. (4) L. Parrano et al. Phytopathol. Mediterr. 51:549, 2012.

First Report of Powdery Mildew Caused by Golovinomyces spadiceus on Industrial Hemp (Cannabis sativa) in Kentucky

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1773-1773 ◽  
Author(s):  
D. Szarka ◽  
L. Tymon ◽  
B. Amsden ◽  
E. Dixon ◽  
J. Judy ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Cannabis Sativa ◽  
First Report ◽  
Industrial Hemp

scholarly journals First Report of Leaf Spot on Industrial Hemp (Cannabis sativa L.) Caused by Alternaria alternata in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Lili Tang ◽  
Xixia Song ◽  
Liguo Zhang ◽  
Jing Wang ◽  
Shuquan Zhang
Keyword(s):  
Leaf Spot ◽  
Cannabis Sativa ◽  
Leaf Spot Disease ◽  
Molecular Characteristics ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Sterile Water ◽  
First Report ◽  
Leaf Spots ◽  
Industrial Hemp

Industrial hemp is an economically important plant with traditional uses for textiles, paper, building materials, food and medicine (Li 1974; Russo et al. 2008; Zlas et al. 1993). In August 2020, an estimated 80% of the industrial hemp plants with leaf spots were observed in greenhouse in Minzhu town, Harbin City, Heilongjiang Province, China (45.8554°N, 126.8167°E), resulting in yield losses of 20%. Leaf symptoms began as small spots on the upper surface of leaves and gradually developed into brown spots with light yellow halos. These irregular spots expanded gradually and eventually covered the entire leaf; the center of the spots was easily perforated. To identify the pathogen, 20 diseased leaves were collected, and small sections of (3 to 5 mm) were taken from the margins of lesions of infected leaves. The pieces were sterilized with 75% alcohol for 30 s, a 0.1% mercuric chloride solution for 1 min, and then rinsed three times with sterile water. Samples were then cultured on potato dextrose agar at 28℃ in darkness for 4 days. A single-spore culture was obtained by monosporic isolation. Conidiophores were simple or branched, straight or flexuous, brown, and measured 22 to 61 μm long × 4 to 5 μm wide (n = 50). Conidia were solitary or in chains, brown or dark brown, obclavate, obpyriform or ellipsoid. Conidia ranged from 23 to 55 μm long × 10 to 15 μm wide (n = 50) with one to eight transverse and several longitudinal septa. For molecular identification (Jayawardena et al. 2019), genomic DNA of pathogenic isolate (MZ1287) was extracted by a cetyltrimethylammonium bromide protocol. Four gene regions including the rDNA internal transcribed spacer (ITS), glyceraldehyde-3-phosplate dehydrogenase (GAPDH), translation elongation factor 1-alpha (TEF1) and RNA polymerase II beta subunit (RPB2) were amplified with primers ITS1/ITS4, GDF1/GDR1, EF1-728F/EF1-986R and RPB2-5F/RPB2-7cR, respectively (White et al. 1990). Resulting sequences were deposited in GenBank with accession numbers of MW272539.1, MW303956.1, MW415414.1 and MW415413.1, respectively. A BLASTn analysis showed 100% homology with A. alternata (GenBank accession nos. MN615420.1, MH926018.1, MN615423.1 and KP124770.1), respectively. A neighbor-joining phylogenetic tree was constructed by combining all sequenced loci in MEGA7. The isolate MZ1287 clustered in the A. alternata clade with 100% bootstrap support. Thus, based on morphological (Simmons 2007) and molecular characteristics, the pathogen was identified as A. alternata. To test pathogenicity, leaves of ten healthy, 2-month-old potted industrial hemp plants were sprayed using a conidial suspension (1×106 spores/ml). Control plants were sprayed with sterile water. All plants were incubated in a greenhouse at 25℃ for a 16 h light and 8 h dark period at 90% relative humidity. The experiment was repeated three times. After two weeks, leaf spots of industrial hemp developed on the inoculated leaves while the control plants remained asymptomatic. The A. alternata pathogen was re-isolated from the diseased leaves on inoculated plants, fulfilling Koch's postulates. Based on morphology, sequencing, and pathogenicity test, the pathogen was identified as A. alternata. To our knowledge, this is the first report of A. alternata causing leaf spot disease of industrial hemp (Cannabis sativa L.) in China and is worthy of our attention for the harm it may cause to industrial hemp production.

scholarly journals Microbiota of Wild Fruits from the Amazon Region of Ecuador: Linking Diversity and Functional Potential of Lactic Acid Bacteria with Their Origin

2020 ◽  
Author(s):  
Gabriela N. Tenea ◽  
Pablo Jarrin-V ◽  
Lucia Yepez
Keyword(s):  
Genetic Resources ◽  
Amazon Region ◽  
Rrna Gene ◽  
Taxonomic Assignment ◽  
Functional Perspective ◽  
Fruit Species ◽  
Wild Fruits ◽  
Assignment Algorithm ◽  
Wide Range ◽  
The Relationship

Subtropical wild fruits are a reservoir of microbial diversity and represent a potential source of beneficial microorganisms. Wild fruits provide essential nutrients, minerals, and antioxidants that contribute to human health. Many of these wild fruits are used by indigenous peoples for medicine and food, but there is yet an unexplored potential in the study of their properties and benefits. Wild fruits from the Amazon region and their associated active substances or bacterial communities can prevent disease, provide appropriate nutrition, contribute to new sources of income, and improve lives. Despite its condition as a megabiodiverse country, Ecuador suffers from limited access to its genetic resources, and particularly for research. A total of 41 isolates were obtained from six wild Amazonian fruit species and were molecularly classified into the genera Lactiplantibacillus (31 isolates), Lactococcus (3 isolates), Weissella (3 isolates), and Enterococcus (1 isolate). Three isolates showed large divergence in sequence variability and were not identified by the taxonomic assignment algorithm. Inferred phylogenies on the 16S rRNA gene explained the relationship between lineages and their origin. Carbohydrate metabolism and antimicrobial profiles were evaluated, and the isolates were classified from a functional perspective. Antimicrobial profiles showed a wide-range spectrum against several Gram-positive and Gram-negative bacteria. To our knowledge, this is the first study assessing the diversity of LAB in native tropical fruits from the Amazon region of Ecuador and their promising functional properties. The obtained isolates and their assessed properties are valuable genetic resources to be further investigated for industrial and pharmaceutical applications.

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