Undulate Margins Research Articles

Prey size and ecological separation in spinosaurid theropods based on heterodonty and rostrum shape.

Members of the dinosaur clade Spinosauridae had numerous traits attributed to feeding in or around water, and their feeding apparatus has often been considered analogous to modern crocodylians. Here we quantify the craniodental morphology of Spinosauridae and compare it to modern Crocodylia. We measured from spinosaurid and crocodylian skeletal material the area of alveoli as a proxy for tooth size to determine size-heterodonty. Geometric morphometrics were also conducted on tooth crowns and tooth bearing regions of the skull. Spinosaurids overall had relatively large alveoli, and both they, and crocodylians, had isolated regions of enlarged alveoli. Spinosaurines also had enlarged alveoli along the caudal dentary that baryonychines lacked, which instead had numerous additional caudal tooth positions. Size-heterodonty was positively allometric, and spinosaurids overlapped with generalist/macro-generalist crocodylians of similar sizes. Spinosaurid crown shape morphologies overlapped with certain slender-longirostrine crocodylians, yet lacked molariform distal crowns typical of most crocodylians. Spinosaurid rostra and mandibles were relatively deep with undulating margins correlating with local tooth sizes, which may indicate a developmental constraint. Spinosaurines had a particularly long concavity caudal to their rosette of anterior cranial teeth, with a corresponding bulbous rostral dentary. The spinosaurid feeding apparatus was well suited for quickly striking and creating deep punctures, but not cutting flesh or durophagy. The jaws interlocked to secure prey and move it deeper into the mouth. The baryonychines probably did little oral processing, yet spinosaurines could have processed relatively large vertebrates. Overall, there is no indication that spinosaurids were restricted to fish or small aquatic prey.

Myrsine cirrhosa (Primulaceae), a distinctive new shrub species from Kaua‘i, Hawaiian Islands

Myrsine cirrhosa Lorence & K.R.Wood (Primulaceae), a new single-island endemic shrub species from Kaua‘i, Hawaiian Islands, is described and illustrated. Notes on its distribution, ecology and conservation status are included. The new species is known from an area with ca. 45 individuals, where it is restricted to the remote central windward region of Kaua‘i in open bogs and along open windy ridges. Suggested IUCN Red List status is CR (Critically Endangered). It differs from its Kaua‘i congeners by its longer petals and narrowly elliptic leaves with strongly undulate margins and tendril-like apex. Phylogenetic analysis using RADseq data supports the recognition of this new species.

First report of Boeremia exigua causing spot blight on cowpea in China.

Cowpea or black-eyed pea [Vigna unguiculata (L.) Walp.] is a dual-purpose leguminous crop grown for food and fodder. In September 2022, cowpea plants exhibiting symptoms of a leaf spot and blight were observed in Renda Town located in Jingning County of Gansu Province, China, with the disease incidence in individual cowpea fields as high as 100%. Diseased leaves showed variable-sized, nearly circular brown blotches, large blotches with dark brown margins, and the adaxial surfaces of blotches had small black dots and whorls (Fig. 1). Multiple isolates with consistent colony characteristics were obtained from cowpea leaves with typical symptoms. The isolates were transferred to fresh potato dextrose agar medium (PDA) and then purified by transferring hyphal tips to PDA. Three isolates, JNJD-1, JNJD-2, and JNJD-3, were selected for subsequent identification and pathogenicity determination. After eight days at 25℃ on PDA, the colonies appeared irregular, aerial mycelium dense, cottony, atrovirens to olive brown, with white hyphae on the undulate margin (Fig. 2A and B). The pycnidia were globose to sub-globose, brown to dark brown, with 70-110 μm diameters. Single celled hyaline conidia were ellipsoidal to oblong with obtuse ends, and measured 6.6-9.3 × 2.8-4.1 μm (x̄ = 7.8 × 3.5 μm, n = 50) (Fig. 2C). Morphological characteristics are similar to the description of the genus Boeremia (Aveskamp et al, 2010). Primer pairs ITS1/ITS4, LR0R/LR5, fRPB2-5F2/fRPB2-7cR, and TUB2FD/TUB4RD were used to amplify portions of the ITS, LSU, RPB2, and TUB genes, respectively (Chen et al, 2015). The obtained sequences (Accession numbers: PP033662 to PP033664 for ITS, PP033667 to PP033669 for LSU, PP035531 to PP035533 for RPB2, and PP035534 to PP035536 for TUB) were 97% identical to that of a B. exigua strain CBS 431.74 (accession no. FJ427001, EU754183, GU371780, and FJ427112) (Table 1). The constructed maximum likelihood tree indicated close relationships between three isolates and B. exigua, which clustered together (Fig. 3). Cowpea plants (cultivar Junlintianxia) at the three-leaf stage were inoculated by spraying a spore suspension (1×106 conidia/ml) of JNJD-1, JNJD-2, and JNJD-3 until run off and incubated at greenhouse conditions (25°C and 12 h light). Inoculations with sterile water were used as a control and each treatment was repeated 3 times with five plants per replicate. Small brown spots appeared on the infected leaves at 2 dpi, followed by the appearance of large blotches, with dark brown at the margin and grayish-white in the center at 5 dpi (Fig. 4A). These lesions gradually increase and coalesce, causing leaf chlorosis and finally defoliation in serious cases. Disease incidence in inoculated cowpea plants treated with the isolates JNJD-1, JNJD-2, and JNJD-3 reached almost 100%. In contrast, control plants developed no symptoms (Fig. 4B). The pathogens were re-isolated from the inoculated leaves and identified as B. exigua using morphological and molecular analysis, whereas no fungus was isolated from control leaves. The experiment was repeated once under the same conditions, yielding similar results. B. exigua has a broad host range, infecting 19 families and 31 genera of plant species, and causing leaf spots, leaf blight, and tuber rot (Lan and Duan 2022). To our knowledge, this is the first report of the pathogen B. exigua causing spot blight on cowpeas. It has been reported that B. exigua infects leguminous crops from multiple genera, such as field pea, soybean, white clover, and Dumasia villosa (Liu et al, 2023). This study further enriches the host range of this pathogen and the pathogen species of cowpea leaf diseases.

Glycomis quangtriensis (Rutaceae), a new species from Quang Tri province, central Vietnam

A new species of Glycosmis (Rutaceae), G. quangtriensis is described based on the specimens collected from the Limestone Razorback Hill and Rockpile Hill, in Huong Hiep Commune, Dakrong District and Cam Tuyen Commune, Cam Lo District, Quang Tri Province, central Vietnam. Morphological description, photographs, a distribution map, vernacular name, and preliminary conservation status are provided for G. quangtriensis. This species is characterized by shrubby habit 1.5 m tall, simple and subsessile leaves, elliptic-oblong lamina with undulate margin and auriculate base, by which combination it is clearly distinguished from all the previously known species in the genus.

First report of anthracnose caused by Colletotrichum grevilleae on apple in Korea.

In October 2022, typical symptoms of anthracnose were observed on apple (Malus ⅹ domestica cv. Fuji) fruits collected from Pocheon in Gyeonggi province, South Korea (N37.98074°, E127.33995°). In the surveyed orchard, the incidence rate of apple anthracnose was less than 1%. The initial symptoms were brown-to-dark brown lesions, and with disease progression, they enlarged and the pulp became soft, forming a brown band. In total 29 apple fruits were collected, and the causal agent was isolated by removing the peel, and the diseased tissues were directly transferred onto potato dextrose agar (PDA), followed by incubation for 7 days at 25°C. As the results, two isolates (GgPc22-1-11 and GgPc22-1-13) were obtained. For describing morphological and cultural characteristics, isolate GgPc22-1-11 was cultured on PDA and synthetic nutrient-poor agar (SNA) at 25°C under near-UV light with a 12-h photoperiod for 10 days. The colonies of GgPc22-1-11 on PDA were initially white and subsequently appeared light gray to olivaceous with white margins. The reverse side of the plates were dark brown and slate blue (Supplementary Fig. S1). Colonies on SNA were flat with an entire margin and short sparse white aerial mycelium. No setae were observed. Conidia on PDA were hyaline, straight, aseptate with a rounded apex, clavate to cylindrical, and measured 16.4 ± 2.4 (10.8-23.8) × 5.5 ± 0.7 (3.6-7.7) μm (n = 200). Appressoria were medium-to-dark brown, aseptate, solitary or in groups with irregular outlines, and lobate or having undulate margins (Supplementary Fig. S1). These morphological and cultural characteristics of GgPc22-1-11 were consistent with those of Colletotrichum grevilleae F. Liu, Damm, L. Cai & Crous, pathogens of Proteaceae and Punica granatum (Liu et al. 2013; Huang et al. 2023). DNA was extracted from GgPc22-1-11, PCR was performed and Phylogenetic analysis of concatenated partial sequences of the internal transcribed spacer (ITS) of rDNA, β-tubulin (TUB2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase 1 (CHS-1), and actin (ACT) genes was conducted (Weir et al. 2012). The resulting sequences were deposited in GenBank under the accession numbers LC773710-LC773714. A nucleotide BLAST search revealed that the ITS sequences of the isolates were 98.95% identical to those of C. grossum CAUG7 (KP890165.1). The TUB2, GAPDH, CHS-1, and ACT sequences of the isolates were 99.79%, 99.24%, 100%, and 100%, respectively, identical to those of C. grevilleae WP4. GgPc22-1-11 was clustered with C. grevilleae WP4 using neighbor joining analysis conducted with MEGA X software (Kumar et al. 2018) (Supplementary Fig. S2). Pathogenicity tests were conducted using GgPc22-1-11 and repeated three times. A total of 12 symptomless apples of each variety were selected, including Fuji, Hongro, Tsugaru, and RubyS. The apples were surface-sterilized with 70% ethanol and wounded using a sterile needle. Both wounded and unwounded apples were inoculated with mycelium plugs and paper disks containing a conidial suspension (1 × 106 conidia/ml) and placed in a plastic box with moist paper towels (>90% relative humidity) at 25°C in dark. At 5 days after inoculation, all artificially wounded fruits exhibited symptoms and 30% (4 out of 12) of unwounded inoculated fruits showed symptoms in each apple variety while control fruits were asymptomatic both the unwounded and wounded inoculations (Supplementary Fig. S1). To fulfill Koch's postulates, the fungi were reisolated from symptomatic tissues and were identical to GgPc22-1-11 confirmed by morphological and molecular analysis. To the best of our knowledge, C. grevilleae has been reported in Protea sp. and pomegranate (Liu et al. 2013; Huang et al. 2023) but not in apples to date, and this is the first report of C. grevilleae causing anthracnose in apple fruits. This research of the newly emerged unreported Colletotrichum species can offer valuable information for development of an effective fungicide spray program to control apple anthracnose.

Characterization of Indigenous Bacillus thuringiensis Isolates and Toxicity Analysis Against Brinjal Shoot and Fruit Borer, Leucinodes orbonalis (Guenee)

The toxins derived from Bacillus thuringiensis (Bt) exhibit significant promise in managing specific orders of harmful insects without the drawbacks in using of chemical insecticides. This study examines 20 indigenous Bt isolates, with a focus on their colony and crystal morphology, gene content, protein profiles, and toxicity against the larvae of Leucinodes orbonalis. The results revealed that all colonies were creamy white in colour with fried egg type appearance, flat surface, and undulated margin with spherical shaped crystals. PCR screening detected the existence of cry1, cry2, and vip3A genes with varying gene combinations among the isolates. Protein profiles exhibited the presence of multiple proteins with molecular weights ranging from 20 to 135 kDa, particularly ~135 and ~65 kDa represents Cry1 and Cry2 protein. In vitro bioassays against L. orbonalis revealed that four isolates T193, T339, T374, and T380 having substantial toxicity (93.33 to 100% mortality), suggesting the potential for their utilization in sustainable pest management strategies.

First report of bacterial leaf spot caused by Pseudomonas cichorii on Monstera adansonii in Hawai'i, USA.

Monstera adansonii is a popular ornamental house plant prized for its small size and unique leaf fenestrations. In Hawai'i, it is also sold as cut foliage (combined value ~$21K; USDA NASS 2019). In January 2022, yellow chlorotic lesions that progressed to greyish-black and, finally, to brown necrotic lesions were observed primarily along the margins of fenestrations on M. adansonii foliage at a plant nursery in Hilo, HI. All 100 variegated specimens in 4-inch pots were infected, exhibiting symptoms along the lighter yellowish-white margins. The green, unvariegated variety planted along a fence for cut foliage exhibited an infection rate of 10%. Symptomatic leaf tissue was disinfected for 1 minute in a 10% bleach solution. Tissue from the margins of leaf spots was subsequently dissected, soaked in sterile distilled water for 1 hour, and plated on Luria-Bertani (LB) agar. Plates contained nearly pure cream-colored bacterial colonies with undulate margins. Isolates were established from single colonies. One isolate (BCB001) was transferred to King's medium B (KMB) and culture fluorescence was observed under 365 nm UV light. Isolate BCB001, which was gram-negative, was identified as Pseudomonas cichorii based on the LOPAT scheme (Schaad et al. 2001). A partial 16S rRNA gene product (495 bp) using primers Y1/Y3 (Cruz et al. 2001) was sequenced and compared in GenBank (accession no. OQ875210) and was 100% identical to multiple accessions of P. cichorii in the NCBI database. Bacterial identity was further confirmed using the P. cichorii-specific primers Hrp1a/Hrp2a (Cottyn et al. 2011) to amplify and sequence a 790 bp fragment (accession no. OQ850761), which was identical to accession no. MH396007, a P. cichorii isolate recovered from Thai basil in Hawai'i. To prove pathogenicity, strain BCB001 was grown on LB agar for 48 h at 27°C and suspended in sterile water at 107-108 CFU/ml. Four healthy, 2-month-old unvariegated M. adansonii plants produced from cuttings were syringe inoculated following the protocol of Wang et al. (2022). Leaves were injected with sterile water using the same methods and acted as negative controls. Plants were placed in clear plastic bags and held at 24°C with 12 h light for 48 hours in a growth chamber, after which time the plants were removed from the bags and incubated under the same conditions for the remainder of the experiment. Leaf spots were not present on any of the control leaves or on noninjected leaves of the plants after five days of incubation. Grey to black, water-soaked leaf spots 0.84 - 15.24 mm in diameter were present on all injected leaves (96% of the injection sites) 2 days post-inoculation (DPI), which were identical to the original diseased samples. At 5 DPI, spots became dark brown to black with a yellow halo, and the affected tissue was completely collapsed. Bacterial colonies were consistently re-isolated from the lesion margins of inoculated plants and morphologically (LB and KMB) and molecularly (Hrp) identified as P. cichorii, thus fulfilling Koch's postulates. To the best of our knowledge, this is the first report of bacterial leaf spot caused by P. cichorii on M. adansonii in Hawai'i. Since M. adansonii is an ornamental plant that is prized for its leaves, leaf spots caused by P. cichorii can reduce the marketability of inventory. To avoid further spread, increasing plant spacing to improving airflow, decreasing the amount of watering, avoiding mist irrigation, and carefully removing and discarding diseased leaves are suggested.

Anatomical and macromorphological data support a new species of Phyllanthus (Phyllanthaceae) from Southeastern Brazil

Phyllanthus megastylus, a new species endemic from Southeastern Brazil, is described here based on anatomical and macromorphological data. It is known so far from the state of Espírito Santo and is morphologically similar to P. itamarajuensis, but differs by its densely papillose branches, pink pistillate flowers, disk pistillate with undulate margin and punctiform stigmas. We provide illustrations, preliminary conservation status, phenological data and images taken in habitat. In addition, the new species it is compared anatomically with similar species and its systematic positioning is discussed.

First Report of Pseudopestalotiopsis theae Causing Leaf Spot on Euonymus japonicus in China.

Euonymus japonicus Thunb., an evergreen shrub, is popular for landscaping in China. In 2021, leaf spot was observed on E. japonicus (about 150 trees) leaves with 40 to 50% disease incidence in Wanzhou urban forest (30°45'N; 108°27'E) of Chongqing, the infected plants were between 5 and 6 years old. The symptoms started to occur from June to July and approximately 30 to 40% of the leaves exhibited leaf spot symptoms from August to September. Initial symptoms appeared as yellow spots of 1.2 to 4.9 mm in diameter, and then expanded to become large and irregular lesions, having white center surrounded by a brown halo. Under humid conditions, black dots appeared in the central part of the spots. In later stage, split and fall of the tissues occurred from the infected spot. To identify the causal agent, infected tissues from 20 samples (from 5 trees) were cut into small pieces (5 mm2), surface-sterilized for 30 s in 75% ethanol and 3 minutes in 3% sodium hypochlorite, rinsed three times in sterile water, placed onto potato dextrose agar (PDA) amended with streptomycin sulfate (50 μg/ml) and incubated at 25°C in dark conditions. Purified eight fungal colonies were white with undulating margins and light cream on the reverse side, measuring 85 mm diameter after 7 days, dark brown to black conidiomata were irregularly scattered and Conidia were observed in 20 days old colonies. Conidia were spindle-shaped, 4.5 to 6.8 × 15.2 to 23.5 μm (n=50), with 4 diaphragms, the three median cells were light to dark brown and the two end cells were colorless. 1 to 3 accessory filaments (5.2 to 22.5 μm long) protrude from theapical cell while a short stalk (3.5 to 5.5 μm long) was attached to the basal cell, these morphological features suggested that the isolates were most likely Pestalotiopsis. sp. Eight colonies were confirmed to be identical based on morphological characteristics. For molecular identification, DNA was extracted from representative strains (YF-5, YF-13, YF-24). The internal transcribed spacer (ITS) region, β-tubulin (TUB2), the translation elongation factor-1 alpha gene (TEF1), genes were amplified using primers ITS5/ITS4, TUB2F/TUB2R, and EF-526F/EF-1567R, respectively (White et al.1990; Glass & Donaldson 1995; O'Donnell & Cigelnik 1997; Carbone &, Kohn.1999). The sequences were deposited in NCBI GenBank YF-24, [ITS; ON204233: TUB2; ON304156: TEF1; ON400075]: YF-5, [ITS; OP379570: TUB2; OP413495: TEF1; OP413496]: YF-13, [ITS; OP379589: TUB2; OP413494: TEF1; OP413497]. Which revealed a 95% similarity to the Ps. theae NTUCC 18-067 [ITS; MT322086: TUB2; MT321888: TEF1; MT321987] ex-type sequences. Based on morphology and multilocus phylogenetic analysis, representative strains were identified as Pseudopestalotiopsis theae. For Koch's postulates, wiped the leaves of six healthy plants of E. japonicus (two-year-old) grown in pots with sterile water, 10 μL of spore suspension (106 spores/ mL) was brushed on five leaves per plant (three plants in total) with a sterile brush, and the other three plants were treated with sterile water instead of spore suspension as control, the plants were placed in a greenhouse at 28°C and 95±1% relative humidity. Seven days after inoculation, brown lesions appeared, similar to those observed in infected plants. Black dots surrounded by a brown halo reappear on the lesions after 12 days, whereas control plants remained healthy. Ps. theae culture was re-isolated from the infected leaves and identified using morphological characteristics and DNA sequence analysis. To our knowledge, Ps. theae can cause diseases on tea plants and has been found in Japan, Thailand and China, this is the first report of leaf spot infection of E. japonicus caused by Ps. theae in China. This disease is reducing the ornamental value of E. japonicus. Our results will contribute to the prevention and cure of leaf spot disease in E. japonicus.

First Report of Neopestalotiopsis Disease in Ohio caused by an emerging and novel species of Neopestalotiopsis on Strawberry.

In October 2021, strawberry (Fragaria x ananassa) plants (cv. Ruby June) that had dark brown lesions with a diffuse black halo and light brown center and / or dark brown V-shaped necrotic areas often starting from the edge of the leaves were observed in a commercial planting in Washington County. The grower reported 50% incidence in the field when the sample was first submitted and two weeks later reported 80% incidence. The morphology of conidia present on symptomatic leaf tissue was consistent with species of Neopestalotiopsis (Maharachchikumbura et al. 2014). The conidia were ellipsoid to fusiform, five-celled, with three light brown colored median cells and one hyaline apical and basal cell. The apical cells had two to four flexuous appendages and the basal cell had one non-flexuous appendage. Average (N=30) conidia length, not including the appendages, and width was 24.1 ± 2.7 and 6.5 ± 1.4 µm respectively. Two isolates (MLI267-21 and MLI268-21) were purified on potato dextrose agar, producing a dense white mycelial mat with undulate margins. The underside color of the mycelial mat was pinkish-orange. Conidiomata formed randomly in the colonies and extruded black gelatinous spores. To confirm the identity of these isolates the genome of MLI267-21 was sequenced using the NextSeq 2000 Illumina platform and Nextera DNA CD indexes (OSU Applied Microbiology Service Laboratory, Columbus, OH). Partial internal transcribed spacer (ITS) region, β-tubulin (TUB), and translation elongation factor 1-alpha (TEF-1α) gene sequences (Accession numbers: OM649904, OM649905, and OM649906 respectively) were extracted from the MLI267-21 genome, concatenated, and aligned to published reference sequences. These same genes were amplified and sequenced from MLI268-21. Maximum likelihood phylogenetic analysis performed in IQ-TREE (Minh et al. 2020, Kalyaanamoorthy et al. 2017, Chernomor et al. 2016) with the aligned sequences revealed the clustering of MLI267-21 and MLI268-21 with seven other Neopestalotiopsis isolates, from strawberry (17-43L; Baggio et al. 2021) and pomegranate (GEV3426 to GEV3431; Xavier et al. 2021) leaves in Florida, which form a unique and emerging species group. The ITS, TUB, and TEF-1α sequences from both Ohio isolates were 100% similar to the same sequences from 17-43L and GEV3426 - GEV3431. Pathogenicity tests were performed using MLI267-21 by spray inoculating (~104 spore/ml) four-week-old 'Cabrillo' strawberry plants (n=4) and placing three drops (10µl each) of spore suspension (~104 spore/ml) on the calix area of detached fruit (n=4). Non-inoculated plants and fruit (n= 4 each) served as negative controls. The plants were covered with transparent plastic bags and maintained at 25 °C for 72 hours before the bags were removed (Baggio et al. 2021). Five days post-inoculation, dark brown circular spots on the leaves and petioles were observed on all four inoculated plants and acervuli were observed within the necrotic spots after an additional 72 hours in a moist chamber. Fruits were incubated in a moist chamber at 25 °C and after 72 hours orange-brown lesions formed on the fruit. After five days, fruit were mushy and covered with white mycelia, acervuli, and conidiomata. Neopestalotiopsis disease has been reported on strawberry in Florida (Baggio et al. 2021) and in several South American (Obregon et al. 2018, Hidrobo et al. 2021) and European (Chamorro et al. 2016, Gilardi et al. 2019) countries. The disease can cause rapid plant death when conditions are warm and wet. Research to investigate host susceptibility and to identify effective chemical and biological control has been initiated in Ohio to establish preventative management programs for commercial field operations.

Cultural and morphological characteristics of Colletotrichum sublineolum isolates infecting sorghum in eastern Ethiopia

Colletotrichum sublineolum is the most destructive pathogen causing sorghum anthracnose worldwide. The fungus is known to have highly variable pathotypes. A characteristic study of pathogen is important to document the change occurring in population as variability in morphology indicates the existence of different pathotypes. Controlled condition experiment was conducted to examine cultural and morphological characteristics of C. sublineolum isolates infecting sorghum in eastern Ethiopia. Sorghum leaves showing symptoms of anthracnose were collected from five districts through survey. To study the characteristics of C. sublineolum, single-spore isolates representing isolate collection districts were selected from the stock cultures and cultivated on potato dextrose agar. Culture growth, colony color, elevations, texture and margin, conidial diameter and shape were used to characterize isolates. The isolates were varied significantly in many aspects. Colony colors were differed from light-gray to gray, purple-gray to cottony-gray, white to salmon-whit, plum-pink to beige and rosy brown on upper side of the petri dishes. The mean culture growth of C. sublineolum isolates showed highly significant (P < 0.01) variations among each other and ranged from 15 to 44 mm eight-days after incubation. Most of the isolates were produced hyaline, smooth walled, falcate conidia but without septa. Conidial diameter of C. sublineolum isolates showed variations with width and length ranged from 2.97 to 6.01 μm and 10.01–27.75 μm, respectively. Most isolates had smooth colony margin and few had undulated margin. This finding revealed that substantial variations were observed among C. sublineolum isolates and the existence of variable characteristic showed the presence of several sub-species of the pathogen infecting sorghum in different agro-ecologies of eastern Ethiopia.

Morpho-Cultural Variability Characterization of Bipolaris oryzae Causing Brown Leaf Spot of Rice in Jammu Sub-Tropics

Extensive fortnightly surveys were undertaken in major rice growing districts of Jammu division to study cultural and morphological variability amongst the isolates of brown leaf spot disease causing fungus (Bipolaris oryzae). Based on disease severity 24 isolates (BO1 to BO24) were divided into three groups (I, II and III). Group ‘I’ comprised 11 isolates with disease severity values between 51.22-67.44% and categorized under highly virulent and group ‘II’ comprised disease severity values between 43.17-48.17% and were categorized under moderately virulent isolates. Group ‘III’ included eight isolates with disease severity value between 26.11-38.17% and categorized under less virulent isolates. On the basis of colony growth pattern, margin and colour, the isolates were categorized into 4 groups (A, B, C and D). Group A comprised of six isolates had entire margin, circular form, umbonate elevation with smooth surface and black to fluffy growth. Eleven isolates were categorised under group B developed colonies with undulated margin, irregular form, umbonate elevation with grey fluffy growth and greyish colour. Group C comprised three isolates had undulated margin, irregular form, umbonate elevation with smooth surface. Group D contained four isolates developed entire margin, circular form; raised elevation with wrinkled surface, mycelium was grey which turned to black and showed grey to black pigmentation. The largest conidial size was recorded in isolate BO1 (98.43-101×24.54-25.54 µm). The conidia developed mean septa of 4.5-7.4 with straight to curve shaped. The sporulation of different isolates of B. oryzae ranged between 6.1-7.6×106 spores/ml.

First Report of Brown Rot Caused by Monilinia polystroma on Quince in Italy

HomePlant DiseaseVol. 107, No. 1First Report of Brown Rot Caused by Monilinia polystroma on Quince in Italy PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Brown Rot Caused by Monilinia polystroma on Quince in ItalyU. Spitaler, S. Oettl, and E. DeltedescoU. Spitaler†Corresponding author: U. Spitaler; E-mail Address: urban.spitaler@laimburg.ithttps://orcid.org/0000-0003-0492-6129Institute for Plant Health, Laimburg Research Centre, Auer (Ora) 39040, South Tyrol, ItalySearch for more papers by this author, S. OettlInstitute for Plant Health, Laimburg Research Centre, Auer (Ora) 39040, South Tyrol, ItalySearch for more papers by this author, and E. Deltedescohttps://orcid.org/0000-0002-0697-3642Institute for Plant Health, Laimburg Research Centre, Auer (Ora) 39040, South Tyrol, ItalySearch for more papers by this authorAffiliationsAuthors and Affiliations U. Spitaler † S. Oettl E. Deltedesco Institute for Plant Health, Laimburg Research Centre, Auer (Ora) 39040, South Tyrol, Italy Published Online:24 Oct 2022https://doi.org/10.1094/PDIS-06-22-1442-PDNAboutSectionsPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Brown rot, caused by Monilinia spp., is an important disease of stone and pome fruits in Italy. The main pathogens are Monilinia laxa, M. fructigena, and M. fructicola. In 2009, a new species, Monilinia polystroma (G. Leeuwen) L. M. Kohn, was found in Europe (Petróczy and Palkovics 2009). The first reports of M. polystroma on pome fruit for Italy were on pear in 2013 (Martini et al. 2015) and on apple in 2021 (Rosati et al. 2021). During a survey in Italy, it was observed that quince (Cydonia oblonga Mill.), a plant of the Rosaceae family and a pome fruit, was frequently affected by brown rot. To determine the pathogen, single spore isolates were obtained from symptomatic fruits of a quince plant in Kaltern/Caldaro (South Tyrol, Italy) in September 2021. On the selected tree, one-third of the fruit showed brown rot symptoms. The isolates showed morphological characteristics compared to M. polystroma on potato dextrose agar (PDA) at 22°C and a photoperiod of 16 h (Vasić et al. 2016). The colonies were grayish brown with slightly undulate margins. The colony reverse developed black stromatal plates in concentric rings within 14 days post inoculation (dpi). DNA was extracted from mycelium and the internal transcribed spacer (ITS) region using ITS6/ITS4 primers (White et al. 1990) as well as a genomic sequence with unknown function using the primers UniMon_Forw/UniMon_Rev (Petróczy et al. 2012), were amplified and sequenced. MegaBLAST analysis revealed 100% identity with M. polystroma (accession nos. NR_154198 and JN128836, respectively). Sequences were deposited in NCBI GenBank under the accession numbers ON646524 and ON806527. To confirm pathogenicity, 10 mature pear quinces from organic production were surface sterilized with 75% ethanol. Mycelial plugs (2 mm) were dislodged from an 8-day-old colony and inserted into a 3 mm hole in the quince. Ten fruits inoculated with sterile PDA plugs were used as a control. Quinces were incubated in a plastic box at 22°C, 16 h photoperiod, and 100% relative humidity. Brown rot lesions developed within 1 day. Additionally, inoculation with spores was performed. One-celled, limoniform, hyaline conidia, measuring 11.7 to 19.4 × 8.8 to 13.1 μm, were obtained from mycelium-inoculated quinces 9 dpi. Ten quinces were wounded with a sterile needle and inoculated with 20 μl conidial suspension (1.1 × 104 spores/ml). Ten quinces inoculated with sterile water were used as a control. After 4 days, brown rot lesions developed on all spore-inoculated fruits. Mean lesion radius (±SD) was 2.5 (±0.8) mm 4 dpi, 25.4 (±1.5) mm 7 dpi, and 45.0 (±4.4) mm 11 dpi. One month after inoculation, all quinces were completely covered by the lesion, while all control fruits remained symptomless. To confirm identity, the fungus was isolated from four spore-inoculated fruit. The isolates showed the same morphological and molecular features as the original isolate. Sequences were deposited in GenBank under the accession numbers ON646525 to ON646528 and ON806528 to ON806531. Although the presence of M. polystroma has been documented for Italy, this is the first report of this species on Italian quinces. The high number of infected fruits found in this study suggests a broad impact of M. polystroma on Italian quince cultivation. Due to the widespread cultivation of quinces, additional knowledge of the occurring pathogens will help to assign brown rot symptoms to M. polystroma and to improve targeted control strategies.The author(s) declare no conflict of interest.

Frustulia hengduanensis sp. nov. a new diatom (Bacillariophyceae) from Hengduan Mountains, China

We describe Frustulia hengduanensis sp. nov., a new species of Frustulia from the Hengduan Mountains in China, based on morphological examinations using light and scanning electron microscopy. Frustulia hengduanensis is characterized by elliptico-lanceolate to rhomboid valves with slightly undulate margins, narrowly rounded and moderately protracted apices, slightly curved longitudinal ribs and raphe, wavy striae along the length of the valve, and an absence of striae within the central part of the valve, forming a dumbbell-shaped hyaline area, this is the main feature that distinguishes the new species from others in the genus. We compared F. hengduanensis sp. nov. with similar taxa and discussed its biogeographical distribution.

Characterization and Evaluation of Indigenous Bacillus thuringiensis Isolate T352 against Fall Armyworm, Spodoptera frugiperda (J.E. Smith)

Bacillus thuringiensis (Bt) Berliner is a ubiquitous soil bacterium with commercial bio pesticidal value and widely used for effective control of various important agricultural insect pests. Invasion of Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) into India caused potential yield loss in maize production, and also it threats the cultivation of other related crops. This study was aimed to characterize and evaluate the pathogenic activity of indigenous Bt isolate T352 against fall armyworm (FAW), S. frugiperda. The Bt isolate T352 was creamy white in colour and had irregular shaped flat colonies with undulated margin. Bipyramidal shape of parasporal inclusions was found in isolate T352. The isolate produced protein bands of ̴ 130 kDa and ̴ 65 kDa size in SDS PAGE analysis. PCR screening also confirmed the presence of cry1Ab, cry1Ac, cry2Aa, cry2Ab and vip3A genes. During probit analysis, isolate T352 exhibited the LC50 of 1.927 µg/ml as against 0.421µg/ml in positive standard strain HD- 1 based on mortality observed at 72 h after treatment in leaf disc bioassay with spore crystal mixtures.

Pinnularia dongzhenensis sp. nov., a new freshwater diatom species (Bacillariophyceae) from Dongzhen Reservoir, Fujian Province, China

A new species of the genus Pinnularia is described, Pinnularia dongzhenensis sp. nov., from the Dongzhen Reservoir, Putian City, Fujian Province, China. This new taxon is characterized by having narrowly linear-lanceolate valves, slightly undulate margins and a slightly constricted center, subcapitate apices, narrow axial area and a central area generally forming an asymmetric, rhomboid fascia. The species is compared to Pinnularia nodosa var. hankensis, P. stauroptera var. longa, P. lange-bertalotii, P. pulchra, P. beyensii and P. daerbinsis, all of which closely resemble Pinnularia dongzhenensis sp. nov. but differ from the new species in specific details of size, valve shape and stria density.

Characterization of indigenous Bacillus thuringiensis isolate RM11 toxic to the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

BackgroundBacillus thuringiensis (Bt) Berliner is an omnipresent soil bacterium used as world’s leading biopesticide to combat agriculturally important insect pests. This study was aimed at protein and gene profiling of an indigenous Bt isolate RM11, which was toxic to the larvae of diamondback moth, Plutella xylostella (L.) in laboratory bioassays.ResultsIndigenous Bt isolate RM11 was characterized along with the standard checks B. thuringiensis subsp. kurstaki (Btk) HD1 and 78/11, based on colony characters, protein profile and PCR screening. All three Bt colonies were fried egg type, white in color with flat elevation and undulated margin. PCR screening revealed the presence of cry1Ac and vip3A genes, which encode lepidopteran toxic proteins in RM11. SDS-PAGE results showed the presence of a prominent protein band of cry1Ac, vip3A with molecular weights 135 kDa, 88 kDa and other bands at 70, 50, 32 and 10 kDa. In leaf disk bioassay with spore crystal mixture, RM11 exhibited toxicity with LC50 of 4.51 µg/ml as against 0.07 µg/ml in positive standard HD1, based on mortality at 72 h after treatment. At LC50 of 4.51 µg/ml, solubilized and insolubilized protein of RM11 was found to produce 56 and 70% mortality.ConclusionsThe present study revealed that RM11 could be a viable alternative for consideration in developing a native Bt formulation and for inclusion in the integrated management of P. xylostella with other native isolates producing different toxins. Furthermore, these findings imply that RM11 could be a source of new cry toxin, which can be confirmed through whole-genome sequencing analysis.

Diversity of indigenous Bacillus thuringiensis isolates toxic to the diamondback moth, Plutella xylostella (L.) (Plutellidae: Lepidoptera)

BackgroundToxins from the Bacillus thuringiensis (Bt) bacterium are employed as an alternative to synthetic pesticides in pest management. The greatest threat to the long-term viability of Bt toxins is resistance evolution in the target pests. Genetic diversity and toxicity of Bt isolates were studied in this work in order to find Bt isolates with novel cry genes.ResultsIn terms of colony morphology, among a total of 60 isolates, 51 isolates had off-white colour colonies with typical fried egg appearance, irregular shape, flat and undulate margin. Different crystal shapes, viz. spherical (88.13%), bipyramidal (49.15%), cuboidal (42.37%), rectangular, and crystals attached to spores (3.38%) were observed among Bt isolates. SDS-PAGE analysis of spore crystal mixture showed the presence of proteins with various molecular weights ranging from 124 to 26 kDa. PCR screening with cry1, cry2, cry9 and vip3A1 primers showed isolates with varied insecticidal gene combinations. Bt isolates containing cry1 genes were found to be abundant (30), followed by cry2 (9) and vip3A1 (9). Cry9 was absent in all the 60 isolates tested. Insecticidal activity of spore crystal mixtures ranged from 0 to 100% mortality. Furthermore, 12 isolates were found to be highly toxic against the larvae of diamondback moth, Plutella xylostella (L.) (Plutellidae: Lepidoptera) with 100% mortality, at 25 µg/ml in leaf disc bioassay.ConclusionsThe present work established the diversity of Bt isolates and confirmed the importance of continuous exploration of new Bt isolates for novel genes. Further, research needs to be carried out to unveil the hidden potential of these toxic isolates.

First Report of Brown Rot Caused by Monilinia polystroma on Apple in Italy.

Brown rot is a common apple disease in Italy, caused by Monilinia fructicola, M. laxa and M. fructigena (Martini et al. 2013). In September 2020, in a 'Jeromine' apple orchard under integrated pest management located in Scarnafigi (44°39'N, 7°33'E, north-western of Italy), fruits (8.6%) showing brown to blackish firm lesions (6.0 to 8.0 cm diameter) were observed. In some fruits, rots were covered by yellowish stromata. Two isolates (MPI1; MPI2) were obtained from two symptomatic apples and cultured on potato dextrose agar (PDA) for 7 days at 25°C in 12-h light/12-h dark regime. A white-to-greyish mycelium with slightly undulate margins and irregular, black stromata developed on PDA after 12 days incubation. Conidia, observed in branched monilioid chains, (Suppl. Fig. 1) were one-celled, globose, limoniform, hyaline, 38 to 58 μm (mean: 48) × 20 to 44 μm (mean: 33). Based on morphology, the isolates were tentatively identified as Monilinia polystroma (G.C.M. Leeuwen) Kohn. A polymerase chain reaction with primers ITS1 and ITS4 was performed on internal transcribed spacer (ITS) region 1 and 2 and 5.8S gene. The sequenced amplicons (435 bp - 445 bp; GenBank Accession No. MW600854; MW600855) showed 100% identity to the reference isolate of M. polystroma (HQ846944) and to other isolates from apples (AM937114; JX315717) and plum (GU067539). The ITS region of M. polystroma had five nucleotides to distinguish it from the closest species M. fructigena (Zhu et al. 2016; MH862738) (Suppl. Fig. 2). The pathogenicity of both isolates was tested on mature 'Jeromine' apples (10.1% total soluble solids). Three replicates of six apples per isolate were surface disinfected with 1% NaClO. A mycelial plug (5 mm) from colony grown on PDA was inserted using a cork borer into a hole (6 mm) in each fruit (Vasić et al. 2016). Apples inoculated with sterile PDA plugs were used as control. Fruits were placed at 22 ± 1 °C, 85% relative humidity and 12 h light/12 h dark regime. Lesion size was measured after 3, 6 and 9 days of incubation. All inoculated fruits developed typical brown rot symptoms 6 days after inoculation and yellowish stromata appeared on the surface; control fruit remained healthy (Suppl. Fig. 3). The virulence of both isolates was statistically similar (Suppl. Table 1). M. polystroma was reisolated from all inoculated fruits and confirmed by molecular methods. This is the first report of M. polystroma on apple in Italy. M. polystroma was previously reported on apple in Hungary (Petróczy et al. 2009), on apricot in Switzerland (Hilber-Bodmer et al. 2012), on peach and pear in Italy (Martini et al. 2014; 2015), on plum in China (Zhu et al. 2016), and on apple in Serbia (Vasić et al. 2018). The emergence of this pathogen for pome and stone fruit production in Europe stimulates to study its biology and epidemiology, and its fitness and management, as compared to the other endemic Monilinia species.

Two New Species of Sciodaphyllum (Araliaceae) from the Andes of Northwestern Colombia

Sciodaphyllum montanum Idárraga, Jiménez-Mont. &amp; Lowry and S. undulatum Jiménez-Mont., Idárraga &amp; Lowry (Araliaceae) from the northern region of the Central and Western Cordilleras of the Andes in Colombia are described and illustrated. Sciodaphyllum montanum differs from other members of the genus mainly by a bulging disc up to 1.1 mm in height and a 3- to 4-carpellate ovary, and S. undulatum is distinguished by its undulate leaflet margin and the conspicuous scarlike amorphous lenticel 4.9–11 mm in diameter located abaxially on the base of the petiole. Notes are provided on possible taxonomic affinities of each species, as well as on their ecology and geographic distribution. Extinction risk assessments are given following the IUCN Red List categories and criteria, which indicate that both S. montanum and S. undulatum are Near Threatened (NT).