Plant-Associated Neoscytalidium dimidiatum-Taxonomy, Host Range, Epidemiology, Virulence, and Management Strategies: A Comprehensive Review.

Neoscytalidium dimidiatum, a plant- and human-associated fungus, has emerged as a substantial global ecological and agricultural threat aggravated by global warming. It inflicts various diseases, including canker, blight, dieback, leaf spot, root rot, and fruit rot, across a wide spectrum of fruit trees, field crops, shrubs, and arboreal species, with a host range spanning 46 plant families, 84 genera, and 126 species, primarily affecting eudicot angiosperms. Six genera are asymptomatic hosts. Neoscytalidium dimidiatum exhibits worldwide distribution, with the highest prevalence observed in Asia and North America, notably in Iran, Turkey, and California. Rising disease prevalence and severity, aggravated by climate change, particularly impact tropical arid places across 37 countries spanning all 7 continents. This comprehensive review encapsulates recent advancements in the understanding of N. dimidiatum, encompassing alterations in its taxonomic classification, host range, symptoms, geographic distribution, epidemiology, virulence, and strategies for effective management. This study also concentrates on comprehending the taxonomic relationships and intraspecific variations within N. dimidiatum, with a particular emphasis on N. oculus and N. hylocereum, proposing to consider these two species as synonymous with N. dimidiatum. Furthermore, this review identifies prospective research directions aimed at augmenting our fundamental understanding of host-N. dimidiatum interaction.

Genome-Wide Identification and Expression Analysis of MTP (Metal Ion Transport Proteins) Genes in the Common Bean.

MTP/CDF carriers, called metal ion transport proteins, act as substrates for the transmission of micronutrients such as iron (Fe), zinc (Zn), and manganese (Mn) to membrane carriers in plants. In this study, genome-wide analysis of the MTP gene family in the common bean genome, expression analysis of the PvMTP4, PvMTP5, and PvMTP12 genes after Fe and Zn treatments, and the effects of Fe and Zn applications on iron and zinc content were investigated. This study used common bean genotypes assumed to have high or low Fe and Zn accumulation ability. PvMTP genes were defined as containing conserved catalytic domains with molecular weights and protein lengths ranging from 41.35 to 91.05 kDa and from 369 to 813 amino acids (aa), respectively. As a result of the phylogenetic analysis, three main clusters containing seven subgroups were formed. In this study, the first characterization of the MTP gene family of beans was performed, and the responses of three different PvMTP genes in the Zn-CDF group to Fe and Zn applications were revealed. The obtained findings are thought to constitute pioneering resources for future research on common bean biofortification studies, plant breeding related to Fe and Zn, and the functional characterization of the MTP gene family.

Molecular phylogeny of plant pathogenic fungi based on start codon targeted (SCoT) polymorphism.

BACKGROUND: A number of molecular marker systems have been developed to assess genetic diversity, carry out phylogenetic analysis, and diagnose and discriminate plant pathogenic fungi. The start codon targeted (SCoT) markers system is a novel approach used here to investigate intra and interspecific polymorphisms of phytopathogenic fungi. MATERIALS AND METHODS: This study assessed genetic variability between and within 96 isolates of ten fungal species associated with a variety of plant species using 36 SCoT primers. RESULTS: The six primers generated 331 distinct and reproducible banding patterns, of which 322 were polymorphic (97.28%), resulting in 53.67 polymorphic bands per primer. All primers produced informative amplification profiles that distinguished all fungal species. With a resolving power of 10.65, SCoT primer 12 showed the highest polymorphism among species, followed by primer 33 and primer 29. Polymorphic loci (PPL), Nei's diversity index (h), and Shannon index (I) percentages were 6.25, 0.018, and 0.028, respectively. UPGMA analysis separated all isolates based on morphological classification and revealed significant genetic variation among fungal isolates at the intraspecific level. PCoA analysis strongly supported fungal species discrimination and genetic variation. The other parameters of evaluation proved that SCoT markers are at least as effective as other DNA markers. CONCLUSIONS: SCoT markers were effective in identifying plant pathogenic fungi and were a powerful tool for estimating genetic variation and population structure of different fungi species.

A novel study on bean common mosaic virus accumulation shows disease resistance at the initial stage of infection in Phaseolus vulgaris.

Accurate and early diagnosis of bean common mosaic virus (BCMV) in Phaseolus vulgaris tissues is critical since the pathogen can spread easily and have long-term detrimental effects on bean production. The use of resistant varieties is a key factor in the management activities of BCMV. The study reported here describes the development and application of a novel SYBR Green-based quantitative real-time PCR (qRT-PCR) assay targeting the coat protein gene to determine the host sensitivity to the specific NL-4 strain of BCMV. The technique showed high specificity, validated by melting curve analysis, without cross-reaction. Further, the symptoms development of twenty advanced common bean genotypes after mechanical BCMV-NL-4 infection was evaluated and compared. The results showed that common bean genotypes exhibit varying levels of host susceptibility to this BCMV strain. The YLV-14 and BRS-22 genotypes were determined as the most resistant and susceptible genotypes, respectively, in terms of aggressiveness of symptoms. The accumulation of BCMV was analyzed in the resistant and susceptible genotypes 3, 6, and 9 days following the inoculation by the newly developed qRT-PCR. The mean cycle threshold (Ct) values showed that the viral titer was significantly lower in YLV-14, which was evident in both root and leaf 3 days after the inoculation. The qRT-PCR thus facilitated an accurate, specific, and feasible assessment of BCMV accumulation in bean tissues even in low virus titers, allowing novel clues in selecting resistant genotypes in the early stages of infection, which is critical for disease management. To the best of our knowledge, this is the first study of a successfully performed qRT-PCR to estimate BCMV quantification.

Fungal Pathogens Associated with Crown and Root Rot in Wheat-Growing Areas of Northern Kyrgyzstan.

Fungal species associated with crown and root rot diseases in wheat have been extensively studied in many parts of the world. However, no reports on the relative importance and distribution of pathogens associated with wheat crown and root rot in Kyrgyzstan have been published. Hence, fungal species associated with wheat crown/root rot were surveyed in three main wheat production regions in northern Kyrgyzstan. Fungal species were isolated on 1/5 strength potato-dextrose agar amended with streptomycin (0.1 g/L) and chloramphenicol (0.05 g/L). A total of 598 fungal isolates from symptomatic tissues were identified using morphological features of the cultures and conidia, as well as sequence analysis of the nuclear ribosomal internal transcribed spacer (ITS) region, the translation elongation factor 1α (TEF1), and the RNA polymerase II beta subunit (RPB2) genes. The percentage of fields from which each fungus was isolated and their relative percentage isolation levels were determined. Bipolaris sorokiniana, the causal agent of common root rot, was the most prevalent pathogenic species isolated, being isolated from 86.67% of the fields surveyed at a frequency of isolation of 40.64%. Fusarium spp. accounted for 53.01% of all isolates and consisted of 12 different species. The most common Fusarium species identified was Fusarium acuminatum, which was isolated from 70% of the sites surveyed with an isolation frequency of 21.57%, followed by Fusarium culmorum, Fusarium nygamai, Fusarium oxysporum, and Fusarium equiseti, all of which had a field incidence of more than 23%. Inoculation tests with 44 isolates representing 17 species on the susceptible Triticum aestivum cv. Seri 82 revealed that Fusarium pseudograminearum and F. culmorum isolates were equally the most virulent pathogens. The widespread distribution of moderately virulent B. sorokiniana appears to be a serious threat to wheat culture, limiting yield and quality. With the exception of F. culmorum, the remaining Fusarium species did not pose a significant threat to wheat production in the surveyed areas because common species, such as F. acuminatum, F. nygamai, F. oxysporum, and F. equiseti, were non-pathogenic but infrequent species, such as Fusarium redolens, Fusarium algeriense, and F. pseudograminearum, were highly or moderately virulent. Curvularia inaequalis, which was found in three different fields, was mildly virulent. The remaining Fusarium species, Fusarium solani, Fusarium proliferatum, Fusarium burgessii, and Fusarium tricinctum, as well as Microdochium bolleyi, Microdochium nivale, and Macrophomina phaseolina, were non-pathogenic and considered to be secondary colonizers. The implications of these findings are discussed.

Multilocus molecular phylogenetic-led discovery and formal recognition of four novel root-colonizing Fusarium species from northern Kazakhstan and the phylogenetically divergent Fusarium steppicola lineage.

In this study, DNA sequence data were used to characterize 290 Fusarium strains isolated during a survey of root-colonizing endophytic fungi of agricultural and nonagricultural plants in northern Kazakhstan. The Fusarium collection was screened for species identity using partial translation elongation factor 1-α (TEF1) gene sequences. Altogether, 16 different Fusarium species were identified, including eight known and four novel species, as well as the discovery of the phylogenetically divergent F. steppicola lineage. Isolates of the four putatively novel fusaria were further analyzed phylogenetically with a multilocus data set comprising partial sequences of TEF1, RNA polymerase II largest (RPB1) and second-largest (RPB2) subunits, and calmodulin (CaM) to assess their genealogical exclusivity. Based on the molecular phylogenetic and comprehensive morphological analyses, four new species are formally described herein: F. campestre, F. kazakhstanicum, F. rhizicola, and F. steppicola.

Clonostachys rosea Strain ST1140: An Endophytic Plant-Growth-Promoting Fungus, and Its Potential Use in Seedbeds with Wheat-Grain Substrate.

In this study, Clonostachys rosea strain ST1140, a naturally occurring endophyte in healthy roots of a pistachio tree, was identified morphologically and molecularly through DNA sequencing, and its endophytic ability and growth effect in/on three solanaceous plant species were tested. Three different organic substrates (bread wheat-grain, sawdust, and leonardite) were also investigated for their utility in cultivating and multiplying the strain. In-tray and pot experiments, the rates of seed germination and vegetative development of pepper, tomato, and eggplant inoculated with C. rosea at planting were compared to those of non-inoculated controls. In pot experiments, inoculating seedbeds with increasing doses of C. rosea strain ST1140 with wheat-grain substrate resulted in higher plant height values for all plant species, and the strain endophytically colonized the roots of all plant species. In-tray experiments revealed that ST1140 inoculation resulted in 2-4 days earlier and 10% higher germination rates for all plant species, as well as more vigorous and accelerated seedling growth (10-13 days earlier for seedlings at the 4-5 true leaf stage) on all inoculated plant species. Among three different organic substrates, wheat-grain was found to be the most effective for long-term cultivation and multiplication of the fungus, which could be of interest for its development as a commercial product. These results promised the strain ST1140's use as a biofertilizer in seedbeds with a wheat-grain substrate.

Identification and Biocontrol Potential of Entomopathogenic Nematodes and Their Endosymbiotic Bacteria in Apple Orchards against the Codling Moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae).

The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is one of the major pests in pome fruit production worldwide. Heavy treatment of the larvae of C. pomonella with insecticides triggered the development of resistance to many groups of insecticides. In addition, the increasing concern about the adverse effects of synthetic insecticides on human health and the environment has led to the development of sustainable and eco-friendly control practices for C. pomonella. The entomopathogenic nematodes (EPNs) (Steinernema and Heterorhabditis spp.) and their endosymbionts (Xenorhabdus and Photorhabdus spp.) represent a newly emerging approach to controlling a wide range of insect pests. In the present study, field surveys were conducted in apple orchards to isolate and identify EPNs and their endosymbionts and evaluate their insecticidal efficacy on the larvae of C. pomonella. EPNs were isolated from 12 of 100 soil samples (12%). Seven samples were identified as Steinernema feltiae (Filipjev, 1934) (Rhabditida: Steinernematidae), whereas five samples were assigned to Heterorhabditis bacteriophora (Poinar, 1976) (Rhabditida: Heterorhabditidae). The pathogenicity of the EPN species/isolates was screened on the last instar larvae of G. mellonella. The two most pathogenic isolates from each EPN species were tested against fifth instar larvae of C. pomonella under controlled conditions. The maximum mortality (100%) was achieved by all EPN species/isolates at a concentration of 100 IJs/larva 96 h after treatment. The endosymbionts of selected H. bacteriophora and S. feltiae species were identified as Photorhabdus luminescens subsp. kayaii and Xenorhabdus bovienii, respectively. The mortality rates ranged between 25 and 62% when the fifth larval instar larvae of C. pomonella were exposed to the treatment of cell-free supernatants of symbiotic bacteria. In essence, the present survey indicated that EPNs and their symbiotic bacteria have good potential for biological control of C. pomonella.

Genetic diversity and population structure of Saccharomyces cerevisiae isolated from Turkish sourdough by iPBS-retrotransposons markers.

Molecular DNA markers are valuable tools for analyzing genetic variation among yeast from different populations to reveal the genetically different autochthonous strains. In this study, we employed inter-primer binding site (iPBS) retrotransposon polymorphism to assess the genetic variation and population structure of 96 Saccharomyces cerevisiae isolates from four different regions in Turkey. The nine selected iPBS primers amplified 102 reproducible and scorable bands, of which 95.10% were polymorphic with an average of 10.78 polymorphic fragments per primer. The average polymorphism information content and the resolving power were 0.26-3.58, respectively. Analysis of molecular variance (AMOVA) revealed significant (P < 0.001) genetic differences within populations (88%) and between populations (12%). The unweighted pair group mean with arithmetic (UPGMA) dendrogram grouped 96 S. cerevisiae strains into two main clusters, where the highest probability of the data elucidating the population structure was obtained at ΔK = 2. There was not an obvious genetic discrimination of the populations according to geographical regions on UPGMA, supported by principal coordinate analysis. However, the individuals of the closer provinces in each population were more likely to group together or closely. The results indicate that iPBS polymorphism is a useful tool to reveal the genetically diverse autochthonous S. cerevisiae strains that may be important for the production of sourdough or baked goods.

Occurrence of Spot Blotch in Spring Barley Caused by Bipolaris sorokiniana Shoem. in South-Eastern Kazakhstan.

In Kazakhstan, barley (Hordeum vulgare L.) is the second most important cereal crop after wheat, with an annual production of approximately 1.9 million tons. The study aimed to characterize Bipolaris sorokiniana isolates obtained from barley fields surveyed. A total of 21 diseased leaves showing spot blotch symptoms were collected from experimental plots located close to the Kazakh Research Institute of Agriculture and Crop Production, where the spring barley Arna cultivar was planted in June 2020. The overall strategy for control of spring barley blotch in the Almaty region of Kazakhstan should include the determination of the aggressiveness of the pathogen isolates to better understand the biology of the diseases and ultimately proper control strategy. Pathogenicity of B. sorokiniana isolates was made on barley seedlings in vitro. Inoculated seedlings showed clear symptoms of B. sorokiniana, and therefore, Koch's postulates were fulfilled by reisolating the pathogen from artificially inoculated seedlings and identifying it based on standard morphology criteria. Further investigation is needed to understand the impact of B. sorokiniana on barley production in Kazakhstan.

Molecular Characterization of Native Entomopathogenic Fungi from Ambrosia Beetles in Hazelnut Orchards of Turkey and Evaluation of Their In Vitro Efficacy.

Ambrosia beetles, Anisandrus dispar Fabricius, Xylosandrus germanus Blandford, and Xyleborinus saxesenii Ratzeburg (Coleoptera: Curculionidae: Scolytinae) are among the most significant hazelnut pests in Turkey. The control of these pests is difficult and expensive due to their biology. The present study aimed to isolate entomopathogenic fungi (EPF) from A. dispar, X. germanus, and X. saxesenii individuals that were obtained from the main hazelnut production areas of Turkey, characterize the EPF isolates using internal transcribed spacer (ITS)-DNA sequencing and iPBS profiling, and determine the efficacy of the isolates against A. dispar, X. germanus, and X. saxesenii under laboratory conditions. Phylogenetic analyses based on ITS revealed that the 47 native isolates were Beauveria bassiana (11), B. pseudobassiana (8), Cordyceps fumosorosea (6), Cordyceps farinosa (1), Akanthomyces lecanii (13), Purpureocillium lilacinum (3), Clonostachys rosea (2) and Metarhizium anisopliae (3). For the first time, the primer binding site (PBS) marker system, based on retrotransposons, was used to discriminate successfully among the EPF species. Some isolates of B. bassiana, B. pseudobassiana, C. fumosorosea, A. lecanii, and M. anisopliae caused 100% mortality of the beetle species within 7 to 9 days. The findings of this study indicated that some isolated entomopathogenic fungi provide an essential basis for the development of bioproducts, as well as a promising alternative method for controlling these ambrosia beetles.

Start Codon Targeted (SCoT) markers for the assessment of genetic diversity in yeast isolated from Turkish sourdough.

Molecular markers are valuable tools for assessing the genetic variation in yeast. Here, we investigated the utility of SCoT markers for the genetic characterization of yeast strains at inter and intraspecies levels. A total of 345 endogenous yeast strains were isolated from 65 Type I sourdough samples collected from six different regions of Turkey. The seven SCoT primers produced 221 bands, of which 95.47% were polymorphic. Each primer could successfully differentiate species, supported by PIC and RP values. The ITS sequencing of isolates selected from the UPGMA dendrogram revealed that Saccharomyces cerevisiae predominated the microflora, followed by Kazachstania servazzii, K. humilis, Wickerhamomyces anomalus, Torulaspora delbrueckii, and Pichia kudriavzevii, respectively. The AMOVA revealed a high genetic variation between (49%) and within populations (51%) for S. cerevisiae. The high gene flow observed among S. cerevisiae populations suggests that it may have contributed to the geographical evolution of S. cerevisiae via the transportation of the sourdough samples. The different geographical origins were most likely to group separately on the UPGMA and PCoA. Saccharomyces cerevisiae strains from more distant populations generally displayed more significant genetic variation. SCoT markers can successfully be used alone or with the other existing DNA markers for DNA fingerprinting and analyzing the genetic variation between and within species.

Diversity and Identification of Plant-Parasitic Nematodes in Wheat-Growing Ecosystems.

Several nematode species can be found in different densities in almost any soil ecosystem, and their diversity in those ecosystems depends on numerous reasons, such as climatic conditions and host presence. Cereals are one of the main hosts of plant-parasitic nematodes (PPN), chiefly root-lesion nematodes (RLN, Pratylenchus spp.) and cereal cyst nematodes (CCN, Heterodera spp.). These nematodes are known as major parasites of the cereal crops; however, agricultural areas accommodate various nematodes showing biological variation. The diversity of parasitic nematodes on cereals in the Sakarya provinces of Türkiye, where cereals are intensively grown and located in the middle of two climatic zones, has not been well studied. Therefore, in this study, we aimed to determine the diversity, identification, and molecular phylogeny of PPNs in wheat-growing ecosystems in the Hendek, Pamukova, Geyve, Akyazi, and Central districts of Sakarya. The diversity of PPNs was calculated using the Shannon diversity index. Thirteen PPN genera were detected in 92% of soil samples. Heterodera filipjevi was identified in 24% of the soil samples using morphological, morphometrical, and molecular tools. In the morphological and molecular analyses, intraspecific polymorphism was observed in H. filipjevi populations. The result indicated that the high infestation rate of H. filipjevi was recorded from Geyve and Pamukova, followed by Hendek and Akyazi; however, a low infestation rate was detected in the Central district. The moderate value of the Shannon index of migratory nematode species was obtained in wheat fields as 2.31, whereas the value of evenness was 0.93, implying moderate diversity and high evenness of nematodes. This study is the first comprehensive report on H. filipjevi from wheat cropping areas in the Sakarya province. Intensified cereal cropping systems with/without non-cereal rotations increased the risk of plant-parasitic nematodes, especially RLNs and H. filipjevi infection of wheat production areas in the province.

Fungal Pathogens Associated with Crown and Root Rot of Wheat in Central, Eastern, and Southeastern Kazakhstan.

Kazakhstan is the fourteenth largest wheat producer in the world. Despite this fact, there has not been a comprehensive survey of wheat root and crown rot. A quantitative survey was conducted for the purpose of establishing the distribution of fungi associated with root and crown rot on wheat (Triticum spp.). During the 2019 growing season, samples were taken from the affected plants' roots and stem bases. A total of 1221 fungal isolates were acquired from 65 sites across the central (Karagandy region), eastern (East Kazakhstan region), and southeastern (Almaty region) parts of the country and identified using morphological and molecular tools. The internal transcribed spacer (ITS), translation elongation factor 1-alpha (EF1-α), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) sequences were successfully used to identify the species of fungal isolates. It was found that Bipolaris sorokiniana (44.80%) and Fusarium acuminatum (20.39%) were the most predominant fungal species isolated, which were present in 86.15 and 66.15% of the fields surveyed, respectively, followed by F. equiseti (10.16%), Curvularia spicifera (7.62%), F. culmorum (4.75%), F. oxysporum (4.10%), F. redolens (2.38%), Rhizoctonia solani AG2-1 (1.06%), Nigrospora oryzae (0.98%), C. inaequalis (0.90%), F. pseudograminearum (0.74%), F. flocciferum (0.74%), Macrophomina phaseolina (0.66%), F. cf. incarnatum (0.33%), Fusarium sp. (0.25%), and F. torulosum (0.16%). A total of 74 isolates representing 16 species were tested via inoculation tests on the susceptible Triticum aestivum cv. Seri 82 and the results revealed that F. culmorum and F. pseudograminearum, B. sorokiniana, Fusarium sp., R. solani, F. redolens, C. spicifera, C. inaequalis, and N. oryzae were virulent, whereas others were non-pathogenic. The findings of this investigation demonstrate the presence of a diverse spectrum of pathogenic fungal species relevant to wheat crown and root rot in Kazakhstan. To the best of our knowledge, this is the first report of F. pseudograminearum, Fusarium sp., C. spicifera, and C. inaequalis as pathogens on wheat in Kazakhstan.

Analysis of genetic diversity among common bean germplasm by start codon targeted (SCoT) markers.

BACKGROUND: Breeding strategies to improve modern varieties having high yield, high nutritional value and resistance to biotic and abiotic stress, etc. is very important to make up for the food deficiencies. Molecular studies as a tool in breeding programs for the characterization of germplasm have been performed with several DNA marker systems. MATERIALS AND METHODS: In the present study, the genetic diversity of 53 common bean landraces and 22 registered varieties from Turkey, and 12 genotypes from USDA was investigated using start codon targeted (SCoT) markers for the first time worldwide. The 8 primers having stronger and more polymorphic bands were used for PCR amplification. RESULTS: The mean polymorphic band of all primers was found as 13.13. The average of polymorphic information content and resolving power values was 0.34 and 7.55, respectively. Analysis of molecular variance (AMOVA) explored the existence of higher genetic diversity within populations accounting for 92% compared to among populations variations. According to cluster analysis (UPGMA) and genetic structure based on SCoT data, accessions were separated into Andean (PopA) and Mesoamerican PopB) gene pools. Moreover, accessions were mostly placed in the same groups/subgroups according to their geographical origin. CONCLUSIONS: A high level of genetic diversity was observed between the investigated accessions in this work. The findings will help to plant breeders to characterize common bean accessions.

Monitoring of Host Suitability and Defense-Related Genes in Wheat to Bipolaris sorokiniana.

Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat worldwide. This study investigated the aggressiveness of B. sorokiniana isolates from different wheat-growing areas of Bolu province in Turkey on the cultivar Seri-82. Host susceptibility of 55 wheat cultivars was evaluated against the most aggressive isolate. Our results indicated that the cultivars Anafarta and Koç-2015 were the most resistant. A specific and sensitive qPCR assay was developed for detecting the pathogen in plant tissues and evaluating wheat plants with different resistance levels. Three primer sets, BsGAPDHF/BsGAPDHR, BsITSF/BsITSR, and BsSSUF/BsSSUR, were designed based on glyceraldehyde-3-phosphate dehydrogenase, internal transcribed spacers, and 18S rRNA loci of B. sorokiniana with detection limits of 1, 0.1, and 0.1 pg of pathogen DNA, respectively. The qPCR assay was highly sensitive and did not amplify DNA from the other closely related fungal species and host plants. The protocol differentiated wheat plants with varying degrees of resistance. The assay developed a useful tool for the quantification of the pathogen in the early stages of infection and may provide a significant contribution to a more efficient selection of wheat genotypes in breeding studies. In the present study, expression levels of PR proteins, phenylalanine ammonia-lyase, catalase, ascorbate peroxidase, and superoxide dismutase enzymes were upregulated in Anafarta (resistant) and Nenehatun (susceptible) cultivars at different post-infection time points, but more induced in the susceptible cultivar. The results showed considerable variation in the expression levels and timing of defense genes in both cultivars.

First Report of Crown Rot Caused by Fusarium algeriense on Wheat in Kyrgyzstan.

Fusarium crown rot of wheat is an economically important disease that leads to significant yield and quality losses, especially in many arid and semi-arid wheat-growing areas worldwide. In June 2020, winter wheat (Triticum aestivum L.) plants exhibiting crown rot symptoms were identified in a commercial field located in the Tokbay location (43.033719°N, 74.325623°E), Chuy Province, Kyrgyzstan. The diseased plants were stunted and had brown discoloration on internodes of the stem bases and roots. Disease incidence was about 3%. A total of 10 plants were sampled at the ripening stage from the field to identify the causal agent. Symptomatic tissues were excised, surface disinfected with 1% NaOCl, rinsed three times with distilled water, and placed on one-fifth strength potato dextrose agar (PDA) followed by incubation at 23°C in the dark for 5 days. A total of 8 Fusarium isolates were recovered from tissues and purified by the hyphal tips method onto fresh PDA and Spezieller-Nährstoffarmer agar (SNA) plates (Leslie and Summerell 2006). Sequence analysis of the translation elongation factor 1α (TEF1) and the RNA polymerase II beta subunit (RPB2) genes were performed with primers EF1 and EF2 (O'Donnell et al. 1998), and 5f2 (Reeb et al. 2004) and 7cr (Liu et al. 1999), respectively. The sequences of three isolates showed 100% identities with the corresponding sequences of the strain NRRL 66652 of Fusarium algeriense Laraba & O'Donnell (TEF1: MF120515 and RPB2: MF120504), and the sequences of a representative isolate (KyrFa01) were deposited in GenBank (TEF1: OM135603 and RPB2: OM135604). On PDA, fungal colonies were initially yellowish-white but gradually turned yellowish-brown. Ellipsoidal microconidia produced in false heads on monophialides were usually aseptate (8.30 ± 1.17 µm, n = 50) and occasionally one-septate (21.89 ± 2.01 µm, n = 50). Sporodochial macroconidia were mostly 3-4 septate measuring 43.41 ± 2.83 µm (n = 50), slightly curved and formed generally on monophialides on SNA. No chlamydospores formation was detected after 15 days on SNA or PDA. Morphological characteristics described above were consistent with the morphology of F. algeriense, as reported by Laraba et al. (2017). To confirm pathogenicity, seeds of wheat cultivar Seri 82, Fusarium crown rot susceptible, were treated in 1% NaOCl for 2 min, rinsed twice, and placed in plates containing a piece of sterile filter paper saturated with water to induce germination for 3 days. Five pregerminated seeds were placed on the soil surface for each 9-cm-diameter pot, which was filled with a sterile potting mix containing peat, vermiculite, and soil (1:1:1 by v/v/v). A 1-cm-diameter mycelial plug taken from the margin of actively growing colonies (PDA) of the representative isolate KyrFa01 was contacted with each seed, and then seeds were covered with the same potting mix. The seeds in control pots were treated with sterile PDA plugs. The experiment was conducted in a growth chamber in a completely randomized design with five replicated pots at 23°C with a 12-h photoperiod. Disease assessment was made after 4 weeks of fungal inoculation. The isolate KyrFa01 induced discoloration on the crown and root tissues of inoculated plants similar to those observed in the field-grown plants, whereas no symptoms were observed on plants grown in the control pots. The pathogen was successfully reisolated from the symptomatic tissues, confirming Koch's postulates. To the best of our knowledge, this is the first report of crown rot caused by F. algeriense on wheat in Kyrgyzstan. Fusarium algeriense was firstly described within the Fusarium burgessii species complex by Laraba et al. (2017) as a crown rot pathogen of wheat in Algeria. The pathogen was secondly reported from wheat-growing areas in Azerbaijan (Özer et al. 2020a) and thirdly from Kyrgyzstan in this report. Özer et al. (2020b) confirmed the coexistence of this pathogen with other Fusarium species. The result warrants the need to further investigate the potential of this species in the Fusarium crown rot complex of wheat.

Characterization and Pathogenicity of Pythium-Like Species Associated with Root and Collar Rot of Kiwifruit in Turkey.

During the period of June to October in 2018, a widespread decline was observed on kiwifruit vines in the vineyards located in the Altinordu, Fatsa, and Persembe districts of Ordu province in Turkey. The symptoms were associated with reddish-brown rots expanding from the root to the collar with sparse off-color foliage. Based on the percentage of the total infected samples across 18 vineyards, the most common oomycete species were Globisporangium intermedium (37.1%), Phytopythium vexans (34.3%), Globisporangium sylvaticum (14.3%), Globisporangium heterothallicum (11.4%), and Pythium dissotocum (2.9%). The morphological identification of isolates was confirmed based on partial DNA sequences containing the nuclear rDNA internal transcribed spacer region gene and the mitochondrial cytochrome c oxidase subunit II gene. The optimum growth temperature and the optimum pH values of the five species ranged from 22.98 to 28.25°C and 5.67 to 8.51, respectively. Pathogenicity tests on the seedlings of kiwifruit cv. Hayward revealed significant differences in virulence among isolates. Phytopythium vexans and Globisporangium sylvaticum isolates caused severe root and collar rot resulting in seedling death, while Globisporangium heterothallicum and Globisporangium intermedium isolates had relatively lower virulence. All Globisporangium spp. and Phytopythium vexans isolates significantly decreased plant growth parameters (plant height, shoot and root dry weights, and root length); however, Pythium dissotocum caused very mild symptoms and did not affect these parameters of growth. To our knowledge, this is the first study reporting Globisporangium sylvaticum, Globisporangium heterothallicum, and Globisporangium intermedium causing root and collar rot on kiwifruit not only in Turkey but also in the world.

First Report of Rhizoctonia solani AG2-1 on roots of wheat in Kazakhstan.

In June 2019, approximately 20 tillers of wheat (Triticum aestivum L.) were sampled at the ripening stage (Feekes scale 11) from four different fields in Almaty, Kazakhstan. Brown lesions (3-5 mm in length) were present on the roots of sampled plants, with 20% incidence. To determine the causal agent, diseased roots were surface disinfected in sodium hypochlorite solution (1%) for 3 min, rinsed triple with sterile distilled water, air-dried in a laminar flow hood, and plated onto one-fifth strength potato dextrose agar (PDA) supplemented with 50 ppm chloramphenicol. After three days, the hyphal fragments that developed from the sections were transferred to fresh PDA and incubated at 23°C with 12-h photoperiod for 7 days to obtain pure cultures. Brown pigmented fungal colonies with a constriction at the base of hyphal branches, septa near the branching point, and right-angled branching resembling Rhizoctonia solani were observed. The identification anastomosis group (AG) of a representative isolate for each field was conducted by sequencing the internal transcribed spacer (ITS) region of rDNA with the universal primers ITS4 and ITS5 (White et al. 1990). The resulting sequences of 693 bp length were deposited in GenBank (accession nos. MW898143:MW898146). These sequences were 100% identical to the isolate 8Rs of R. solani AG2-1 (accession no. AF354063). To confirm the pathogenicity of the four isolates, the colonized wheat kernels method described by Demirci (1998) was used to inoculate a sterile potting mix containing peat, vermiculite, and soil (1:1:1 by v/v/v) into which wheat (cv. Seri) was planted. Control pots were inoculated with sterile wheat kernels using the same procedure. Wheat plants were left to grow for four weeks under controlled environmental conditions with a 23°C temperature regime. During the period that the plants remained in the glasshouse, the typical light regime was 16 h. Brown lesions were observed on the roots of plants in the inoculated pots whereas no symptoms were observed on plants grown in the control pots. R. solani was consistently reisolated from symptomatic plants, thereby confirming Koch's postulates. To our knowledge, this is the first report of R. solani AG2-1 on roots of wheat in Kazakhstan. R. solani AG2-1 isolates have been previously reported to be a weak pathogen to wheat (Roberts and Sivasithamparam 1986; Sturrock et al. 2015; Jaaffar et al. 2016; Özer et al. 2019). We suggest further studies are required to characterize the impact of R. solani AG2-1 in wheat. Considering crop rotation, the selection of non-host crops to this AG group is important to pathogen management, by reducing the amount of inoculum in the soil.