DNA barcoding and scanning electron microscopy reveals Erysiphe ahmadii sp. nov. and a new record Erysiphe populicola (Erysiphaceae, Helotiales) on salicaceous hosts from Pakistan.

A new species of powdery mildew fungus Erysiphe ahmadii and a new record, Erysiphe populicola, on Salicaceae are described from Pakistan. In addition to light microscopy, scanning electron microscopy is also done to clearly demonstrate the surface characters of chasmothecia. E. ahmadii sp. nov. is characterized by large conidia ((-26)29-35(-37) × (-16)17-21(-23) µm), long chasmothecial appendages (198-286 µm) and small conidiophores. The novelty is confirmed by analyzing the genetic variation of internal transcribed spacer region (ITS1-5.8S-ITS2) of the ribosomal DNA gene, a universal fungal marker. E. populicola is characterized for the first time using molecular phylogenetic markers. Detailed descriptions along with scanning electron microscopy (SEM) photographs are provided in this paper. RESEARCH HIGHLIGHTS: Powdery mildews are obligate biotrophic pathogens of plants. Erysiphe ahmadii, a new powdery mildew fungus on willow trees, is described. First reference sequence of Erysiphe populicola is also generated. Both taxa are discussed in detail using macro- and micro-morphological and DNA barcoding techniques.

New species and new records of genus Buellia (lichenized Ascomycota, Caliciaceae) from Pakistan using electron microscopy and DNA barcoding techniques.

Three new species Buellia darelensis, B. densitheca, B. kashmirensis and two new records B. elegans and B. taishanensis are added to the lichen biota of Pakistan. Buellia darelensis and B. kashmirensis share the same habitats found on the rock while B. densitheca colonized on bark of Pinus hardwoods in the Himalayan forest, Pakistan. Morphological, chemical, and phylogenetic analyses were carried out to elucidate the placement of these species and to support the delimitation of the new taxa. Detailed descriptions and figures for the species are given, and a key to all known buellioid species from Pakistan is provided. RESEARCH HIGHLIGHTS: During recent explorations of lichens from different regions of Pakistan, we observed specimens that could not be readily assigned to any known species. A phylogenetic analysis of the internal transcribed spacer nrDNA region confirms their position within the genus Buellia, and morphological data showed distinctiveness of three species from other known species of the genus. We therefore describe these specimens as new species to science, and two species are as new records for the country. Pakistan exhibits a large altitudinal variation, with climatic conditions and a diverse vegetation that supports a diverse and conspicuous lichen biota. The nature reserves have abundant biological resources, and it is expected that more new species of lichen may be discovered in the future.

First Report of Leaf Spot Caused by Corynespora cassiicola on Jasminum sambac in Pakistan.

Jasminum sambac L. is a species of jasmine native to a small region in the eastern Himalayas and is cultivated worldwide as an ornamental plant (USDA-ARS 2016). In Pakistan, it is cultivated for ornamental purposes throughout the country. The flowers of this plant are traditionally used in the preparation of essential oils and for making jasmine tea. The flowers and leaves also have been used in folk medicine to treat breast cancer, epilepsy, ulcers and promote wound healing (Al-Snafi 2018). In December, 2017, almost 10 leaves of 3 plants of J. sambac growing plant nursery of Gehlan, Pattoki, Punjab a province of Pakistan were observed with leaf spot disease. Infected leaves exhibited circular to sub-circular spots with indistinct margins and grey papery centers delimited by dark brown rims. For further microscopic study, the infected leaves were examined under a stereomicroscope. For the isolation and cultural studies of infecting fungus, infected parts of leaves were surface sterilized in 1% NaOCl for about 10 seconds, washed twice in sterilized distilled water, plated on potato dextrose agar (PDA) medium and incubated at 25°C for 4 days. Pure cultures were obtained having colonies of light to dark brown color. Conidia (n=20) were light brown to pale olivaceous brown, smooth, obclavate to cylindrical in shape, 99.5-118.5 µm in length and 12.5-15.0 µm in width, with mostly 3 to 14 pseudosepta. Conidiophores (n=20) were straight to slightly curved, unbranched, and pale to light brown in color. Based on the morphological characteristics of the colonies and conidiophores and conidia, the pathogen was identified as Corynespora cassiicola (Berk and M.A. Curtis) C.T. Wei. (Berkeley & Curtis 1968; Lu et al. 2021; Wei 1950). Genomic DNA was extracted following using modified CTAB method (Gardes and Bruns 1993) and internal transcribed spacer (ITS) region was amplified with ITS1 and ITS4 primers (White et al. 1990). The ITS sequence generated of about 553 bp and deposited in GenBank (accession no. MN954556), was found more than 99% similar to previously deposited sequences of C. cassiicola (GenBank accession nos. MN339671, EU364535, FJ852574, MK139711, EU131374) as verified through BLASTn and phylogenetic tree construction. A pathogenicity test was performed for fulfilling Koch'spostulates. Conidial suspension (105 conidia/ml) of the recovered isolate was sprayed on the 5 healthy leaves of 2-month-old seedling of J. sambac. Mock inoculated plants sprayed sterile distilled water were used as a control. The seedlings were covered with plastic bags to maintain high humidity at 24 to 28°C for a week. Identical disease symptoms to those observed in nursery plants were observed on the leaves of the inoculated plants in 7 days but not mock inoculated plants and results were reconfirmed. The reoccurred fungus was isolated from the diseased spots of the inoculated leaves to complete Koch's postulates and identified microscopically. A representative sample of leaves with lesions was deposited in the LAH herbarium, Department of Botany University of the Punjab, Pakistan (LAH35691). Previously, C. cassicola has been found infecting Jasminum mesnyi in China and Jasminum sp. in Florida (Alfieri et al. 1984; Zhang et al. 2018). The best of our knowledge, this is the first report of leaf spot caused by C. cassiicola on J. sambac in Pakistan. It will establish a foundation for future studies of management strategies for this plant disease caused by C. cassiicola.

Tulostoma loonbanglaense: A new species from Azad Jammu and Kashmir using light and scanning electron microscopy and DNA barcoding technique.

Tulostoma loonbanglaense sp. nov. is described from Azad Jammu and Kashmir, Pakistan. ITS sequences confirm its position within the genus Tulostoma, and suggest that it is separate from other identified species of this genus. The species has globose to subglobose, with wide, solitary and appressed spines basidiospores, the basidiospores are relatively small, 4.39 × 4.23 µm, that make it distinguished from the related species. Sequences of nr ITS region of the newly described species nested as a distinct taxon in both phylogenetic analyses of the current study.

First Report of the Rust Disease Caused by Puccinia crepidis-japonicae on New Host Sonchus arvensis from Pakistan.

Sonchus arvensis (Asteraceae) is a traditional medicinal herb. The aerial parts are a rich source of vitamins, essential amino acids, and minerals, which may help in treatment of fever, inflammation, detoxication, and blood circulation (Li et al. 2018). In October 2018, typical rust symptoms were observed on S. arvensis leaves and stems in Buner district, Malakand division, Khyber PakhtunKhwa Province, Pakistan (34.39°N; 72.61°E). Almost 40% of leaves and stems of five S. arvensis plants displayed severe rust. The specimens were examined microscopically and compared with type specimen description in published literature (Dietel 1908; Hiratsuka et al. 1992). The fungus was identified as Puccinia crepidis-japonicae based on the characteristic of spore morphology and phylogenetic study based on the internal transcribed spacer (ITS) and large subunit (LSU) sequence data. Uredinia were amphigenous, rounded, or somewhat elliptical, naked, small patches, equally spread, brown. Urediniospores (n=30) were globose to ellipsoid, brownish yellow and measured 22.4-24.7 × 20.2-22.1 µm. Urediniospore walls were brownish orange and finely echinulate and 1.7 to 2.1 µm thick with 2 to 3 germ pores. Telia were amphigenous, rounded or elliptic, scattered, dark brown to blackish. Teliospores (n=30) were ellipsoid, subglobose or long ellipsoid, rounded at both ends, not thickened at apex, warted, reddish brown, and measured 31.3-39 × 24.6-26.8 µm. Teliospore walls were reddish-black and about 1.5-2.5 µm thick, and the pedicles were short, hyaline, fragile, become tapered toward apex, and measured 14.4-18.7 × 4.7-9 µm. DNA was extracted from urediniospores, and the combined region of ITS and LSU (28S) were amplified using Rust2Inv (forward primer) and LR6 (Reverse primer) according to the protocol outlined by Aime (2006). A BLASTn search (http://www.ncbi.nlm.nih.gov) showed that the combined ITS and LSU region shared 99% identity (792/804 bp) to the P. crepidis-japonicae accessions (KY798395 from Hawaii, USA) with 100% query cover. The resulting sequence was deposited in GenBank (Accession No. MN093335). Both morphological and molecular characteristics indicatethat this species was P. crepidis-japonicae. To test pathogenicity and fulfill the Koch's postulates, a urediniospore suspension (1 × 104 spores/ml) was sprayed on three 6-week-old plants of S. arvensis, and one as negative control, incubated at 22-24°C. Uredinia were observed on the leaves after 10 days of inoculation, whereas the control plants remained symptomless. Microscopic examination confirmed that the symptoms on plants obtained from the field and greenhouse inoculations were morphologically identical. This fungus has been observed previously on Crepis japonica in China, Hong Kong, Japan, Korea, and Taiwan, on Prenanthes spp. in China and on Youngia tenuifolia and Y. fusca in China (Farr and Rossman 2021). Pereira et al. (2002) suggested that P. crepidis-japonicae may play a significant role as a biocontrol agent against its weed host. To the best of our knowledge, there are no other reports of this fungus on any other hosts in Pakistan. The specimen has been vouchered in LAH Herbarium, Department of Botany, University of the Punjab, Lahore, Pakistan (LAH36343). This is the first report of P. crepidis-japonicae on S. arvensis as a new host from Pakistan.

The genus Coprinellus (Basidiomycota; Agaricales) in Pakistan with the description of four new species.

Mushrooms with a thin-fleshed pileus that becomes plicate on opening, deliquescent lamellae and dark brown to blackish basidiospores are commonly called coprinoid mushrooms. The genus Coprinellus is one of the important lineages of coprinoid mushroom in the family Psathyrellaceae. Species-level taxonomy in Coprinellus is based mainly on the presence or absence and the structure of veil and cystidia on the pileus, of cystidia on the lamellae and on basidiospore morphology. In this study, four new species of Coprinellus (Co.campanulatus, Co.disseminatus-similis, Co.pakistanicus and Co.tenuis) are described from Pakistan. Species descriptions are based on morphological and molecular data. Phylogenetic analyses based on nuc rDNA ITS region show that the new species Co.campanulatus and Co.disseminatus-similis are clustered in a clade including members of section Micacei; Co.tenuis falls in a clade with members of section Domestici; and Co.pakistanicus recovered in a separate clade adjacent to other recently described clades of genus Coprinellus. Morpho-anatomical descriptions of the new species and comparison with closely allied taxa are provided. With this study, the number of known species of Coprinellus in Pakistan has reached eight.

The genus Parasola in Pakistan with the description of two new species.

Parasola is a genus of small, veil-less coprinoid mushrooms in the family Psathyrellaceae (Agaricales). The genus is not well documented in Asia, specifically in Pakistan. In this study we describe two new species Parasola glabra and P. pseudolactea from Pakistan, based on morphological and molecular data. Phylogeny based on three DNA regions: nuc rDNA region encompassing the internal transcribed spacers 1 and 2 along with the 5.8S rDNA (ITS), nuc 28S rDNA D1-D2 domains (28S) and translation elongation factor 1α gene (TEF1α) show that the new taxa are clustered in a clade formed by the members of section Parasola of genus Parasola. Parasola glabra with grayish pileus, slightly depressed pileal disc, lamellae separated from the stipe by pseudocollarium, basidiospores 14.5-16.5 × 9.5-11.5 × 8.0-10.5 µm, in front view broadly ovoid to oblong, some with rhomboidal outline, in side view ellipsoid, with eccentric germ-pore of 1.5 µm diameter. Parasola pseudolactea with yellowish brown to dull brown pileus, disc indistinctly umbonate, lamellae free, pseudocollarium absent, basidiospores 13.5-14.5 × 10.5-12.0 × 9.5-10.5 µm, in face view rounded triangular to heart shaped, rarely ovoid to subglobose, in side view ellipsoid to oblong, with eccentric germ-pore of 1.5 µm diam. In addition to these new species, P. auricoma and P. lilatincta were also studied. Morphological descriptions for the new species and comparison with known Parasola species are provided. Our observations highlight the diversity of Parasola in northern Pakistan and further document the need for additional systematic focus on the region's fungi.