Antagonistic properties against Fusarium sporotrichioides and glycosylation of HT-2 and T-2 toxins by selected Trichoderma strains.

The present study assessed the ability of Trichoderma to combat F. sporotrichioides, focusing on their antagonistic properties. Tests showed that Trichoderma effectively inhibited F. sporotrichioides mycelial growth, particularly with T. atroviride strains. In co-cultures on rice grains, Trichoderma almost completely reduced the biosynthesis of T-2 and HT-2 toxins by Fusarium. T-2 toxin-α-glucoside (T-2-3α-G), HT-2 toxin-α-glucoside (HT-2-3α-G), and HT-2 toxin-ß-glucoside (HT-2-3ß-G) were observed in the common culture medium, while these substances were not present in the control medium. The study also revealed unique metabolites and varying metabolomic profiles in joint cultures of Trichoderma and Fusarium, suggesting complex interactions. This research offers insights into the processes of biocontrol by Trichoderma, highlighting its potential as a sustainable solution for managing cereal plant pathogens and ensuring food safety.

A Comparison of the Prevalence of Gastrointestinal Parasites in Wild Boar (Sus scrofa L.) Foraging in Urban and Suburban Areas.

The aim of this study was to compare the species composition of gastrointestinal parasites in wild boar feeding in the city of Szczecin with those in its suburban area, as well as to determine the prevalence and intensity of this parasite infection. The intestines and stomachs of 57 wild boars were supplied by a municipal hunter from the city of Szczecin. Both analysed groups of animals were infected with the following parasites: Eimeria debliecki, E. suis, E. polita, E. scabra, Isospora suis, Ascaris suum and Oesophagostomum dentatum. Wild boar from the city were characterised as having a significantly higher prevalence of total Eimeria (p = 0.04) and a lower prevalence of noted species of nematodes (p = 0.15) compared to those from the suburban area. Since the wild boars were mainly infected with Eimeria, it should be assumed that they may pose a real health threat to farm pigs and other farm animals for which Eimeria is a pathogenic parasite. The occurrence of coccidiosis leads to serious health problems and economic losses for breeders. Although the prevalence of A. suum was low, it should be taken into account that this nematode is able to both infect and complete their life cycle in humans.

Constellation of the endophytic mycobiome in spring and winter wheat cultivars grown under various conditions.

The mycobiome is an integral component of every living organism. Among other fungi associated with plants, endophytes are an interesting and favorable group of microorganisms, but information regarding them is still largely unknown. Wheat is the most economically significant and essential crop for global food security, which is exposed to a range of abiotic and biotic stresses. Profiling plants' mycobiomes can help in sustainable, chemical-reducing wheat production. The main objective of this work is to understand the structure of endogenous fungal communities in winter and spring wheat cultivars growing under different growth conditions. Further, the study attempted to investigate the effect of host genotype, host organs and plant growth conditions on the composition and distribution of fungi in wheat plant tissues. Comprehensive, high throughput analyzes of the diversity and community structure of the wheat mycobiome were performed, complemented by the simultaneous isolation of endophytic fungi, resulting in candidate strains for future research. The findings of the study revealed that the type of plant organs and growth conditions influence the wheat mycobiome. It was also assessed that fungi representing the genera Cladosporium, Penicillium, and Sarocladium form the core mycobiome of Polish spring and winter wheat cultivars. The coexistence of both symbiotic and pathogenic species in the internal tissues of wheat was also observed. Those commonly considered beneficial for plants can be used in further research as a valuable source of potential biological control factors and/or biostimulators of wheat plant growth.

Containment of Fusarium culmorum and Its Mycotoxins in Various Biological Systems by Antagonistic Trichoderma and Clonostachys Strains.

Prevention of fungal diseases caused by Fusarium species, including F. culmorum, and thus the accumulation of mycotoxins in wheat ears, is a constant challenge focused on the development of new, effective crop management solutions. One of the currently most ecologically attractive approaches is biological control using natural antagonistic microorganisms. With this in mind, the antagonistic potential of thirty-three Clonostachys and Trichoderma strains was assessed in this work. Screening tests were carried out in in vitro cultures, and the observed potential of selected Trichoderma and Clonostachys strains was verified in field and semi-field experiments with two forms of wheat: winter cv. Legenda and spring cv. Bombona. Three strains, namely C. rosea AN291, T. atroviride AN240 and T. viride AN430 were reported to be most effective in inhibiting the growth of F. culmorum KF846 and the synthesis of DON, 3AcDON and ZEN under both laboratory and semi-controlled field conditions. Observations of the contact zones of the tested fungi in dual cultures exposed their mycoparasitic abilities against KF846. In addition, studies on liquid cultures have demonstrated the ability of these strains to eliminate F. culmorum toxins. Meanwhile, the strains of T. atroviride AN35 and T. cremeum AN392 used as soil inoculants in the field experiment showed a different effect on the content of toxins in ears (grains and chaffs), while improved wheat yield parameters, mainly grain health in both wheat cultivars. It is concluded that the selected Trichoderma and Clonostachys strains have a high potential to reduce the adverse effects of F. culmorum ear infection; therefore, they can be further considered in the context of potential biocontrol factors and as wheat crop improvers.

Trichoderma versus Fusarium-Inhibition of Pathogen Growth and Mycotoxin Biosynthesis.

This study evaluated the ability of selected strains of Trichoderma viride, T. viridescens, and T. atroviride to inhibit mycelium growth and the biosynthesis of mycotoxins deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEN), α-(α-ZOL) and ß-zearalenol (ß-ZOL) by selected strains of Fusarium culmorum and F. cerealis. For this purpose, an in vitro experiment was carried out on solid substrates (PDA and rice). After 5 days of co-culture, it was found that all Trichoderma strains used in the experiment significantly inhibited the growth of Fusarium mycelium. Qualitative assessment of pathogen-antagonist interactions showed that Trichoderma colonized 75% to 100% of the medium surface (depending on the species and strain of the antagonist and the pathogen) and was also able to grow over the mycelium of the pathogen and sporulate. The rate of inhibition of Fusarium mycelium growth by Trichoderma ranged from approximately 24% to 66%. When Fusarium and Trichoderma were co-cultured on rice, Trichoderma strains were found to inhibit DON biosynthesis by about 73% to 98%, NIV by about 87% to 100%, and ZEN by about 12% to 100%, depending on the pathogen and antagonist strain. A glycosylated form of DON was detected in the co-culture of F. culmorum and Trichoderma, whereas it was absent in cultures of the pathogen alone, thus suggesting that Trichoderma is able to glycosylate DON. The results also suggest that a strain of T. viride is able to convert ZEN into its hydroxylated derivative, ß-ZOL.

Expression Patterns of miR398, miR167, and miR159 in the Interaction between Bread Wheat (Triticum aestivum L.) and Pathogenic Fusarium culmorum and Beneficial Trichoderma Fungi.

Bread wheat (Triticum aestivum L.) is an agronomically significant cereal cultivated worldwide. Wheat breeding is limited by numerous abiotic and biotic stresses. One of the most deleterious factors is biotic stress provoked by the Fusarium culmorum fungus. This pathogen is a causative agent of Fusarium root rot and Fusarium head blight. Beneficial fungi Trichoderma atroviride and T. cremeum are strong antagonists of mycotoxigenic Fusarium spp. These fungi promote plant growth and enhance their tolerance of negative environmental conditions. The aim of the study was to determine and compare the spatial (in above- and underground organs) and temporal (early: 6 and 22 hpi; and late: 5 and 7 dpi reactions) expression profiles of three mature miRNAs (miR398, miR167, and miR159) in wheat plants inoculated with two strains of F. culmorum (KF846 and EW49). Moreover, the spatial expression patterns in wheat response between plants inoculated with beneficial T. atroviride (AN35) and T. cremeum (AN392) were assessed. Understanding the sophisticated role of miRNAs in wheat-fungal interactions may initiate a discussion concerning the use of this knowledge to protect wheat plants from the harmful effects of fungal pathogens. With the use of droplet digital PCR (ddPCR), the absolute quantification of the selected miRNAs in the tested material was carried out. The differential accumulation of miR398, miR167, and miR159 in the studied groups was observed. The abundance of all analyzed miRNAs in the roots demonstrated an increase in the early and reduction in late wheat response to F. culmorum inoculation, suggesting the role of these particles in the initial wheat reaction to the studied fungal pathogen. The diverse expression patterns of the studied miRNAs between Trichoderma-inoculated or F. culmorum-inoculated plants and control wheat, as well as between Trichoderma-inoculated and F. culmorum-inoculated plants, were noticed, indicating the need for further analysis.

Fungi Inhabiting the Wheat Endosphere.

Wheat production is influenced by changing environmental conditions, including climatic conditions, which results in the changing composition of microorganisms interacting with this cereal. The group of these microorganisms includes not only endophytic fungi associated with the wheat endosphere, both pathogenic and symbiotic, but also those with yet unrecognized functions and consequences for wheat. This paper reviews the literature in the context of the general characteristics of endophytic fungi inhabiting the internal tissues of wheat. In addition, the importance of epigenetic regulation in wheat-fungus interactions is recognized and the current state of knowledge is demonstrated. The possibilities of using symbiotic endophytic fungi in modern agronomy and wheat cultivation are also proposed. The fact that the current understanding of fungal endophytes in wheat is based on a rather small set of experimental conditions, including wheat genotypes, plant organs, plant tissues, plant development stage, or environmental conditions, is recognized. In addition, most of the research to date has been based on culture-dependent methods that exclude biotrophic and slow-growing species and favor the detection of fast-growing fungi. Additionally, only a few reports of studies on the entire wheat microbiome using high-throughput sequencing techniques exist. Conducting comprehensive research on the mycobiome of the endosphere of wheat, mainly in the context of the possibility of using this knowledge to improve the methods of wheat management, mainly the productivity and health of this cereal, is needed.

Sarocladium and Lecanicillium Associated with Maize Seeds and Their Potential to Form Selected Secondary Metabolites.

The occurrence and diversity of Lecanicillium and Sarocladium in maize seeds and their role in this cereal are poorly understood. Therefore, the present study aimed to investigate Sarocladium and Lecanicillium communities found in endosphere of maize seeds collected from fields in Poland and their potential to form selected bioactive substances. The sequencing of the internally transcribed spacer regions 1 (ITS 1) and 2 (ITS2) and the large-subunit (LSU, 28S) of the rRNA gene cluster resulted in the identification of 17 Sarocladium zeae strains, three Sarocladium strictum and five Lecanicillium lecanii isolates. The assay on solid substrate showed that S. zeae and S. strictum can synthesize bassianolide, vertilecanin A, vertilecanin A methyl ester, 2-decenedioic acid and 10-hydroxy-8-decenoic acid. This is also the first study revealing the ability of these two species to produce beauvericin and enniatin B1, respectively. Moreover, for the first time in the present investigation, pyrrocidine A and/or B have been annotated as metabolites of S. strictum and L. lecanii. The production of toxic, insecticidal and antibacterial compounds in cultures of S. strictum, S. zeae and L. lecanii suggests the requirement to revise the approach to study the biological role of fungi inhabiting maize seeds.

Divergence of Beauvericin Synthase Gene among Fusarium and Trichoderma Species.

Beauvericin (BEA) is a cyclodepsipeptide mycotoxin, showing insecticidal, antibiotic and antimicrobial activities, as well as inducing apoptosis of cancer cell lines. BEA can be produced by multiple fungal species, including saprotrophs, plant, insect and human pathogens, particularly belonging to Fusarium, Beauveria and Isaria genera. The ability of Trichoderma species to produce BEA was until now uncertain. Biosynthesis of BEA is governed by a non-ribosomal peptide synthase (NRPS), known as beauvericin synthase (BEAS), which appears to present considerable divergence among different fungal species. In the present study we compared the production of beauvericin among Fusarium and Trichoderma strains using UPLC methods. BEAS fragments were sequenced and analyzed to examine the level of the gene's divergence between these two genera and confirm the presence of active BEAS copy in Trichoderma. Seventeen strains of twelve species were studied and phylogenetic analysis showed distinctive grouping of Fusarium and Trichoderma strains. The highest producers of beauvericin were F. proliferatum and F. nygamai. Trichoderma strains of three species (T. atroviride, T. viride, T. koningiopsis) were minor BEA producers. The study showed beauvericin production by Fusarium and Trichoderma species and high variance of the non-ribosomal peptide synthase gene among fungal species from the Hypocreales order.

Changes in root-associated fungal communities in Triticum aestivum ssp. spelta L. and Triticum aestivum ssp. vulgare L. under drought stress and in various soil processing.

Plant roots are inhabited by an enormous variety of microorganisms, including fungi, which can control the growth as well as regulate the health of the host plants. The mycobiome composition of the roots of wheat plants, especially spelt, under drought stress has been rarely investigated. Therefore, the aim of the present study was to examine the composition of fungal communities in the root endosphere and rhizosphere of three Triticum aestivum ssp. spelta L. cultivars and one Triticum aestivum ssp. vulgare L. cultivar, grown under drought and controlled conditions in different soil preparations. Culture-dependent fungal community profiling was performed to examine the impact of rhizocompartments (endosphere, rhizosphere), host genotype, watering status and different soil preparation on roots mycobiome structure. A total of 117 fungal strains, belonging to 22 genera, were found to colonize the internal and external parts of roots in T. aestivum ssp. spelta L. and T. aestivum ssp. vulgare L. cultivars. The results showed that the part of root and soil preparation type significantly determined the mycobiome composition of wheat roots.

Plant Cell Wall Changes in Common Wheat Roots as a Result of Their Interaction with Beneficial Fungi of Trichoderma.

Plant cell walls play an important role in shaping the defense strategies of plants. This research demonstrates the influence of two differentiators: the lifestyle and properties of the Trichoderma species on cell wall changes in common wheat seedlings. The methodologies used in this investigation include microscopy observations and immunodetection. In this study was shown that the plant cell wall was altered due to its interaction with Trichoderma. The accumulation of lignins and reorganization of pectin were observed. The immunocytochemistry indicated that low methyl-esterified pectins appeared in intercellular spaces. Moreover, it was found that the arabinogalactan protein epitope JIM14 can play a role in the interaction of wheat roots with both the tested Trichoderma strains. Nevertheless, we postulate that modifications, such as the appearance of lignins, rearrangement of low methyl-esterified pectins, and arabinogalactan proteins due to the interaction with Trichoderma show that tested strains can be potentially used in wheat seedlings protection to pathogens.

Growth and Photosynthetic Activity of Selected Spelt Varieties (Triticum aestivum ssp. spelta L.) Cultivated under Drought Conditions with Different Endophytic Core Microbiomes.

The role of the microbiome in the root zone is critically important for plants. However, the mechanism by which plants can adapt to environmental constraints, especially water deficit, has not been fully investigated to date, while the endophytic core microbiome of the roots of spelt (Triticum aestivum ssp. spelta L.) grown under drought conditions has received little attention. In this study, we hypothesize that differences in the endophytic core of spelt and common wheat root microbiomes can explain the variations in the growth and photosynthetic activity of those plants, especially under drought conditions. Our greenhouse experimental design was completely randomized in a 2 × 4 × 3 factorial scheme: two water regime levels (well-watered and drought), three spelt varieties (T. aestivum ssp. spelta L.: 'Badenstern', 'Badenkrone' and 'Zollernspelz' and one wheat variety: T. aestivum ssp. vulgare L: 'Dakotana') and three mycorrhizal levels (autoclaved soil inoculation with Rhizophagus irregularis, control (autoclaved soil) and natural inoculation (non-autoclaved soil-microorganisms from the field). During the imposed stress period, relative water content (RWC), leaf chlorophyll fluorescence, gas exchange and water use efficiency (WUE) were measured. Microscopic observations of the root surface through fungi isolation and identification were conducted. Our results indicate that 'Badenstern' was the most drought tolerant variety, followed by 'Zollernspelz' and 'Badenkrone,' while the common wheat variety 'Dakotana' was the most drought sensitive. Inoculation of 'Badenstern' with the mycorrhizal fungi R. irregularis contributed to better growth performance as evidenced by increased whole plant and stalk dry matter accumulation, as well as greater root length and volume. Inoculation of 'Zollernspelz' with arbuscular mycorrhizal fungi (AMF) enhanced the photochemical efficiency of Photosystem II and significantly improved root growth under drought conditions, which was confirmed by enhanced aboveground biomass, root dry weight and length. This study provides evidence that AMF have the potential to be beneficial for plant growth and dry matter accumulation in spelt varieties grown under drought conditions.

Development of high-resolution melting PCR (HRM-PCR) assay to identify native fungal species associated with the wheat endosphere.

Understanding the complexity and biodiversity of fungal communities associated with the wheat endosphere can facilitate the identification of novel strains that might be beneficial to the host plant. However, the differentiation and taxonomic classification of the endosphere-associated fungi with respect to various cultivars and plant organs are challenging, time-consuming, and expensive, even with the use of molecular techniques. In the present work, we describe a fast, simple, and low-cost method based on high-resolution melting PCR (HRM-PCR) for the identification and differentiation of wheat endogenous fungal isolates. Using this approach, we differentiated 28 fungal isolates, which belonged to five different genera, namely Alternaria, Penicillium, Epicoccum, Fusarium, and Trichoderma. Furthermore, the results of the study revealed that this method can allow large-scale screening of cultured samples.

Occurrence of Mycotoxigenic Fusarium Species and Competitive Fungi on Preharvest Maize Ear Rot in Poland.

Maize has become one of the most important crops for food and feed production-both as a silage and crop residue worldwide. The present study aimed to identify the co-occurrence of Fusarium subglutinans, Fusarium verticillioides, Trichoderma atroviride, Sarocladium zeae, and Lecanicillium lecanii on maize ear rot. Further, the accumulation of mycotoxins as secondary metabolites of Fusarium spp. in maize ear samples was also analyzed. Maize ear samples were collected between 2014 and 2017 from two main maize growing areas in Poland (Greater Poland and Silesia region). A significant difference was found in the frequency of two main Fusarium spp. that infect maize ears, namely F. subglutinans and F. verticillioides. In addition to Fusarium spp. T. atroviride, S. zeae, and L. lecanii were also identified. T. atroviride species was found in 14% of maize samples examined between 2014 and 2017, particularly with a high percentage of Trichoderma spp. recorded in 2014, i.e., in 31% of samples. However, mycotoxin content (beauvericin and fumonisins) varied, depending on both the location and year of sampling. The interaction of fungi and insects inhabiting maize ear and kernel is very complex and not yet elucidated. Therefore, further research is required in this area.

Screening and Identification of Trichoderma Strains Isolated from Natural Habitats with Potential to Cellulose and Xylan Degrading Enzymes Production.

A total of 123 Trichoderma strains were isolated from different habitats and tested for their ability to degrade cellulose and xylan by simple plate screening method. Among strains, more than 34 and 45% respectively, exhibited higher cellulolytic and xylanolytic activity, compared to the reference strain T. reesei QM 9414. For strains efficiently degrading cellulose, a highest enzyme activity was confirmed using filter paper test, and it resulted in a range from 1.01 to 7.15 FPU/ml. Based on morphological and molecular analysis, the isolates were identified as Trichoderma. The most frequently identified strains belonged to Trichoderma harzianum species. Among all strains, the most effective in degradation of cellulose and xylose was T. harzianum and T. virens, especially those isolated from forest wood, forest soil or garden and mushroom compost. The results of this work confirmed that numerous strains from the Trichoderma species have high cellulose and xylan degradation potential and could be useful for lignocellulose biomass conversion e.g. for biofuel production.

Suppressive Effect of Trichoderma spp. on toxigenic Fusarium species.

The aim of the present study was to examine the abilities of twenty-four isolates belonging to ten different Trichoderma species (i.e., Trichoderma atroviride, Trichoderma citrinoviride, Trichoderma cremeum, Trichoderma hamatum, Trichoderma harzianum, Trichoderma koningiopsis, Trichoderma longibrachiatum, Trichoderma longipile, Trichoderma viride and Trichoderma viridescens) to inhibit the mycelial growth and mycotoxin production by five Fusarium strains (i.e., Fusarium avenaceum, Fusarium cerealis, Fusarium culmorum, Fusarium graminearum and Fusarium temperatum). Dual-culture bioassay on potato dextrose agar (PDA) medium clearly documented that all of the Trichoderma strains used in the study were capable of influencing the mycelial growth of at least four of all five Fusarium species on the fourth day after co-inoculation, when there was the first apparent physical contact between antagonist and pathogen. The qualitative evaluation of the interaction between the colonies after 14 days of co-culturing on PDA medium showed that ten Trichoderma strains completely overgrew and sporulated on the colony at least one of the tested Fusarium species. Whereas, the microscopic assay provided evidence that only T. atroviride AN240 and T. viride AN255 formed dense coils around the hyphae of the pathogen from where penetration took place. Of all screened Trichoderma strains, T. atroviride AN240 was also found to be the most efficient (69-100% toxin reduction) suppressors of mycotoxins (deoxynivalenol, 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, nivalenol, zearalenone, beauvericin, moniliformin) production by all five Fusarium species on solid substrates. This research suggests that T. atroviride AN240 can be a promising candidate for the biological control of toxigenic Fusarium species.

Trichoderma species occurring on wood with decay symptoms in mountain forests in Central Europe: genetic and enzymatic characterization.

The aim of this study was to explore the species diversity of Trichoderma obtained from samples of wood collected in the forests of the Gorce Mountains (location A), Karkonosze Mountains (location B) and Tatra Mountains (location C) in Central Europe and to examine the cellulolytic and xylanolytic activity of these species as an expression of their probable role in wood decay processes. The present study has led to the identification of the following species and species complex: Trichoderma atroviride P. Karst., Trichoderma citrinoviride Bissett, Trichoderma cremeum P. Chaverri & Samuels, Trichoderma gamsii Samuels & Druzhin., Trichoderma harzianum complex, Trichoderma koningii Oudem., Trichoderma koningiopsis Samuels, C. Suárez & H.C. Evans, Trichoderma longibrachiatum Rifai, Trichoderma longipile Bissett, Trichoderma sp. (Hypocrea parapilulifera B.S. Lu, Druzhin. & Samuels), Trichoderma viride Schumach. and Trichoderma viridescens complex. Among them, T. viride was observed as the most abundant species (53 % of all isolates) in all the investigated locations. The Shannon's biodiversity index (H), evenness (E), and the Simpson's biodiversity index (D) calculations for each location showed that the highest species diversity and evenness were recorded for location A-Gorce Mountains (H' = 1.71, E = 0.82, D = 0.79). The preliminary screening of 119 Trichoderma strains for cellulolytic and xylanolytic activity showed the real potential of all Trichoderma species originating from wood with decay symptoms to produce cellulases and xylanases-the key enzymes in plant cell wall degradation.

Conception rates in farm mink (Neovison vison) in relation to first mating date, age and color variety.

The aim of the study was to analyze the effects of the first mating date, age and color variety on the conception rates in farm mink. We analyzed female mink reproductive performance in 492 Sapphire and 463 Standard Black females over 3 or 4 years. The analysis included the number of inefficient matings, the interval between the first inefficient mating and the efficient mating (copulation) and the conception rates. The results show a significant effect of female's age and color variety on the conception rates. The youngest, yearling females of either color needed a higher number of matings per conception, as compared to older, 2- and 3-year-old females. Black females demonstrated a higher number of inefficient matings (1.066), as compared with Sapphires (0.730). Yearling females were most often mated from 1 to 10 March, and older females from 11 to 20 March. Older females achieved better conception rates than the yearlings. Dates between 11 and 25 March proved to be the optimum for the first mating, since the highest conception rates were observed if the females had mated during this period.

Tubulin cytoskeleton during microsporogenesis in the male-sterile genotype of Allium sativum and fertile Allium ampeloprasum L.

KEY MESSAGE: Microsporogenesis in garlic. The male-sterile Allium sativum (garlic) reproduces exclusively in the vegetative mode, and anthropogenic factors seem to be the cause of the loss of sexual reproduction capability. There are many different hypotheses concerning the causes of male sterility in A.sativum; however, the mechanisms underlying this phenomenon have not been comprehensively elucidated.Numerous attempts have been undertaken to understand the causes of male sterility, but the tubulin cytoskeleton in meiotically dividing cells during microsporogenesis has never been investigated in this species. Using sterile A.sativum genotype L13 and its fertile close relative A. ampeloprasum (leek), we have analysed the distribution of the tubulin cytoskeleton during microsporogenesis. We observed that during karyokinesis and cytokinesis, in both meiotic divisions I and II, the microtubular cytoskeleton in garlic L13 formed configurations that resembled tubulin arrangement typical of monocots. However, the tubulin cytoskeleton in garlic was distinctly poorer (composed of a few MT filaments) compared with that found in meiotically dividing cells in A. ampeloprasum. These differences did not affect the course of karyogenesis, chondriokinesis, and cytokinesis, which contributed to completion of microsporogenesis, but there was no further development of the male gametophyte. At the very beginning of the successive stage of development of fertile pollen grains, i.e. gametogenesis, there were disorders involving the absence of a normal cortical cytoskeleton and dramatically progressive degeneration of the cytoplasm in garlic. Therefore,we suggest that, due to disturbances in cortical cytoskeleton formation at the very beginning of gametogenesis, the intracellular transport governed by the cytoskeleton might be perturbed, leading to microspore decay in the male-sterile garlic genotype.