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Article

Endophyte Viability in Grass Seeds: Storage Conditions Affecting Survival and Control Methods

by
Barbara Wiewióra
and
Grzegorz Żurek
*
Plant Breeding & Acclimatization Institute, National Research Institute in Radzików, 05-870 Błonie, Poland
*
Author to whom correspondence should be addressed.
Agronomy 2025, 15(8), 1977; https://doi.org/10.3390/agronomy15081977
Submission received: 11 July 2025 / Revised: 6 August 2025 / Accepted: 14 August 2025 / Published: 15 August 2025
(This article belongs to the Special Issue Plant–Microbiota Interactions Under Abiotic Stress)
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Abstract

Research has evaluated the efficacy of various methods for eliminating endophytes from grass seeds, as well as changes in endophyte viability during seed storage under different conditions, indicating significant variation in different procedures and cultivars. Chemical seed treatment (tebuconazole and thiram) completely eliminated viable fungal mycelia, leaving no trace in any tested cultivar. Non-chemical methods, such as drying and microwave treatment, only partially reduced mycelial viability by 30.3% and 33.1%, respectively, with no statistically significant difference between them. A significant positive correlation was observed between the initial mycelial viability and its reduction. Lolium perenne cv. Vigor showed no impact from non-chemical methods, while Festuca rubra cv. Anielka exhibited the greatest reduction (79% after microwave treatment). Seed storage also impacted endophyte survival. Storage at +7 °C, +23 °C, and −20 °C reduced viability by 27.4%, 31.7%, and 37.3%, respectively. Positive correlations existed between initial viability and post-storage reductions. Similarly to elimination methods, cv. Vigor showed resistance to storage conditions. However, −20 °C storage proved least favorable for endophyte survival, particularly for Festuca pratensis cv. Artema, cv. Anielka, and Festuca ovina cv. Jolka. To maintain the viability of beneficial endophytes during seed storage, we must carefully control storage conditions, especially ambient temperature.

1. Introduction

Endophytes are microorganisms that colonize plant tissues without causing disease symptoms. They play a crucial role in promoting plant growth, increasing their resistance to biotic (e.g., pathogens, pests) and abiotic stresses (e.g., drought, salinity), and generally improving the condition of host plants [1,2]. In the context of temperate forage grasses, endophytic fungi of the genus Epichloë (formerly classified as Neotyphodium) are particularly important. Their presence is often associated with increased drought tolerance in grasses, as well as resistance to diseases and pests, which translates into higher yields and better forage quality [2,3,4]. However, despite many benefits, the presence of endophytes can also be undesirable in certain situations. Some Epichloë strains produce toxic alkaloids that can be harmful to grazing animals, leading to “fescue toxicosis”, which can be categorized as a form of poisoning or a disease syndrome induced by external factors [5]. For this reason, both understanding the dynamics of endophyte viability in seeds during storage and developing effective methods to remove them from planting material are extremely important for agriculture and plant breeding.
Epichloë fungi are often referred to as “seed-borne fungi” due to their ability to effectively transmit with seeds [6,7,8,9,10,11]. It is important to note that caryopses colonized by these fungi do not show visible symptoms of their presence, which makes visual identification difficult [12]. Epichloë mycelium primarily colonizes the aleurone layer of seeds; however, its distribution in grass caryopses can vary depending on the grass species and endophyte strain (Figure 1).
Many researchers have studied in detail the distribution of Epichloë endophyte mycelia in grass seeds. These observations consistently indicate a high concentration of mycelia in the aleurone layer, often in close proximity to the embryo, suggesting a tight association with the developing embryo [13,14,15]. More recent studies confirm these findings and provide more precise information on the interaction of the mycelium with seed tissues. For example, Zhang et al. [16] used advanced microscopic techniques to demonstrate that the mycelium is typically concentrated in the aleurone and often envelops the embryo, which facilitates its vertical transmission to the next generation of plants.
The viability of endophytes in seeds is a critical factor for their successful transmission to subsequent plant generations. This viability is closely linked to seed age [17,18]. The available literature extensively documents that, in addition to storage duration, environmental conditions during storage, primarily air temperature and seed moisture and ambient humidity, also significantly impact endophyte viability [13,19,20,21]. Newer research confirms these relationships and provides more detailed data. For instance, Tian et al. [22] conducted comprehensive analyses of the effect of various temperature and humidity combinations on the survival of Epichloë lolii in perennial ryegrass seeds, clearly indicating that low temperatures and low humidity are optimal for maintaining long-term endophyte viability. Similarly, Hume et al. [23] emphasize that the careful management of seed storage conditions is decisive for maintaining endophyte viability, which is critical for breeding programs utilizing these mutualistic fungi. Additionally, Caradus et al. [24] also highlight the need for the precise monitoring of storage conditions to maximize endophyte survival in seed banks.
The ability to eliminate endophytes from grass seeds is a crucial issue from the perspective of forage cultivar breeding and holds significant practical importance. In many countries, including France, current legal regulations require that the endophyte infection of seeds does not exceed 20% for cultivars submitted for registration [25]. These requirements stem from the existing threat of diseases in cattle grazing on pastures colonized by grasses with endophytes that produce harmful alkaloids. Despite the fact that endophytes can offer some benefits, such as increased drought resistance or reduced populations of certain pests, the potential negative effects on animal health outweigh the risks, especially when these benefits are minor [25].
Newer research and regulations often differentiate endophyte strains based on their alkaloid profiles. For example, in the United States and New Zealand, breeding programs and markets are being developed for grasses with “novel endophytes”. These novel endophytes produce alkaloids beneficial to plants (e.g., increasing insect resistance) but do not produce toxins harmful to animals [26,27,28]. Nevertheless, the elimination or strict control of toxin-producing endophytes remains a priority in countries with stringent regulations regarding feed safety. This is particularly important for cultivars intended for intensive grazing. The development of effective and economically viable methods for eliminating endophytes from seeds without negatively impacting their germination capacity is still the subject of intensive research [29].
Our research hypothesis was that endophyte viability decline differs significantly depending on the grass species, variety, and seed storage conditions. We predict that distinct optimal storage conditions exist for maintaining high endophyte viability in Festuca spp. seeds compared to those established for Lolium perenne or Poa pratensis. Therefore, the objective of this research was to evaluate endophyte viability in grass seeds before and after storage under various conditions, which could help establish optimal seed storage strategies. Additionally, the study aimed to examine the effectiveness of the selected methods for eliminating these fungi from planting material, which is crucial for producing endophyte-free seeds when their presence is undesirable.

2. Materials and Methods

For the studies that were conducted from March to May of 2020, we selected seeds from 7 cultivars of 6 grass species with varying known endophyte colonization levels. These included two cultivars of Festuca pratensis (FP cv. Artema, FP cv. Skra) and one cultivar each of Lolium perenne (LP cv. Vigor), F. rubra (FR cv. Anielka), F. ovina (FO cv. Jolka), F. arundinacea (FA cv. Terros), and Poa pratensis (PP cv. Balin).
All analyses including seed germination were assessed for each grass species and cultivars on a sample of 4 × 100 seeds per cultivar. Seed germination was estimated according to ISTA rules [30]. Analysis confirmed that the best seed storage conditions that do not significantly reduce germination were 7 °C and 10% humidity (Table S1 in Supplementary Materials). Furthermore, the only method of eliminating endophytes that did not negatively impact seed germination was the use of chemical seed treatment with the active ingredients tebuconazole and thiram (Table S2 in Supplementary Materials).
Endophyte viability, both initial and post-storage, was assessed using an indirect method, namely sowing seeds and examining seedlings (4 × 100 per cultivar) for the presence of the mycelium. Analyses were conducted before (control) and after 9 months of seed storage under three different environmental conditions as follows:
(a)
Variable temperature, average +23 ± 5 °C, variable humidity (56 ± 5%) (S_1);
(b)
Stable temperature +7 °C, stable humidity 55% (S_2);
(c)
Stable temperature −20 °C, stable humidity 10% (S_3).
To study endophyte elimination from seeds, three methods were chosen, which were (1) storing seeds in a forced air circulation laboratory drying oven at 38 °C and 50% humidity for 5 days; (2) exposing seeds to microwave radiation at 90 W for 10 min; and (3) applying seed treatment Raxil Gel® (systemic fungicide with active ingredients tebuconazole 6 g/L and thiram 200 g/L, Bayer Crop Science, Monheim, Germany). Considering the latter, dressing was performed immediately before sowing at a dose of 5 mL of gel per 1 kg of seeds in a seed dressing machine, where the measured amount of the agent was added to the cleaned seeds and mixed for approx. 5 min.
Seeds of all grass species and cultivars treated in the above-described manner were sown at the same time in a greenhouse in sterilized potting mix. Seeds were sown into multi-cell trays, with the aim of producing 400 seedlings per cultivar used. When the seedlings were 2 months old, the staining method [31] was used to check for the presence of endophyte mycelium in the plants grown from these seeds. Four replications of one hundred tillers per cultivar were examined for the presence of endophytes.
The obtained results were further analyzed, and all calculations were made with STATISTICA® for Windows, ver.13.3. The experimental design comprised two separate experiments with the same genotypes, with four replications per genotype in each experiment. A separate two-way ANOVA was conducted for each experiment to assess the effect of the identified sources of variation and their potential interaction.
The significance of differences between means and Pearson’s correlation coefficients was accepted with 99% probability.

3. Results

3.1. Effect of Seed Storage Conditions on Endophyte Viability

Both the cultivars and the seed storage methods used had a highly significant effect on the variation in endophyte survival. A statistically significant interaction between these experimental factors was also found (Table 1).
The studied cultivars exhibited substantial variation in the observed viability of endophytic mycelia, both at the outset of the experiment and following 9 months of seed storage under different conditions (Figure 2). The results indicated that in most cultivars, storage, regardless of temperature, led to a decrease in endophyte viability compared to the control group. Endophytes colonizing the perennial ryegrass cultivar Vigor demonstrated exceptional stability, maintaining 100% viability across all storage conditions. Conversely, Epichloë fungi in FP cv. Artema, FR cv. Anielka, FA cv. Terros, and PP cv. Balin exhibited the lowest viability values after storage. There was only a small difference in viability between the low-temperature storage conditions (−20 °C and +7 °C) and the laboratory room temperature (+23 °C). For these cultivars, any form of storage appears to significantly reduce endophyte viability.
Endophytes colonizing the FP cv. Skra showed a noticeable decrease in viability from the initial value (100%, control) to 60% after storage at both +23 °C and −20 °C but maintained slightly better viability at +7 °C (90%). In FO cv. Jolka, there was also a decrease in endophyte viability across all storage conditions, with the lowest rate observed in the freezer (−20 °C). For most cultivars, storage at −20 °C generally resulted in the lowest or one of the lowest endophyte viability rates (e.g., FP cv. Artema, FR cv. Anielka, FO cv. Jolka, FA cv. Terros, PP cv. Balin).

3.2. Effectiveness of Methods for Eliminating Epichloë from Seeds

Similarly to the applied seed storage conditions, the endophyte elimination methods were also found to have a statistically significant effect on the variation in endophyte survival, along with a significant effect from the cultivars and the interaction between these factors (Table 2).
We observed significant differences in the efficacy of the applied endophyte elimination procedures, as well as variability among the tested cultivars, both in terms of initial endophyte mycelial viability and its viability after using non-chemical elimination methods (Figure 3). We found that drying generally led to a decrease in endophyte viability in most cultivars compared to the control. The Epichloë genotype colonizing the LP cv. Vigor cultivar was a clear outlier, maintaining 100% viability even after drying, which indicates exceptional dehydration resistance. For endophytes in other cultivars, drying reduced viability by less than 50% (FO cv. Jolka—44.4%), exactly 50% (FP cv. Skra, FP cv. Artema), to even over 50% (FA cv. Terros—58.8%, PP cv. Balin—73%) relative to the control. The average viability after drying was 53.7% (±5.2%), representing a significant drop compared to the control.
Microwave treatment also led to a significant decrease in endophyte viability in most of the tested cultivars. Similarly to drying, the Epichloë colonizing LP cv. Vigor maintained 100% viability after microwave treatment. Lower endophyte viability after microwave treatment, compared to drying, was observed in the seeds of the remaining tested cultivars (e.g., FP cv. Artema, FR cv. Anielka, FA cv. Terros, PP cv. Balin). An exception was the results for endophytes in FP cv. Skra, which had higher viability after microwaving (70%) than after drying (50%). The average viability after microwaving was 42.8% (±6.4%), which is slightly lower than after drying (Figure 3).
Among the tested grass cultivars, only the LP cv. Vigor showed no effect of non-chemical methods on endophyte mycelium viability. Conversely, FR cv. Anielka exhibited the relatively largest reduction in endophyte mycelium viability; after microwave treatment, mycelium viability dropped to 30% of its initial value, representing a 79% reduction. Statistical analysis showed that the differences in effectiveness between the two non-chemical methods were not statistically significant (t = 1.12, p = 0.273).
The most drastic effect was observed after applying the chemical seed treatment Raxil Gel® as endophyte viability in all tested cultivars dropped to 0%. This indicates that the chemical method used for endophyte elimination was fully effective across all tested cultivars, completely destroying the Epichloë fungi colonizing them.
The research consistently showed a strong positive correlation between the initial viability of endophytes and their viability after either storage or treatment with various elimination methods (Table 3). This means that endophytes with higher initial viability tended to maintain that viability better or experienced a less drastic decline compared to those that started with lower viability.
The results also highlight that while physical methods (temperature, microwaves) can significantly reduce endophyte viability, chemical seed treatments, such as using Raxil Gel®, are the most effective method for removing endophytes from grass seeds.

4. Discussion

The viability of endophytes in seeds is a crucial factor influencing their spread and successful colonization of new plants. It is strongly dependent on seed age and storage conditions. The research presented in this paper showed significant differences in endophyte survival duration depending on the storage method, which is consistent with findings from other authors. For instance, Bouter and Klooster [32] analyzed the colonization of Lolium perenne seeds stored under uncontrolled conditions. Their results clearly indicated that the viability of endophyte mycelium in such seeds lasted for only one year. In contrast, Siegel et al. [13] observed significantly longer survival, with seeds stored at 0–5 °C and near-zero humidity containing viable mycelium even after 15 years. Welty et al. [21] concluded that storage conditions which do not reduce seed germination capacity are generally suitable for maintaining endophyte viability. In their study, the survival period of mycelium in tall fescue and perennial ryegrass seeds was similar, although a tendency for faster viability decline was noted in tall fescue.
More recent studies confirm these dependencies and provide additional information. Tian et al. [22] thoroughly analyzed the impact of different temperatures and humidities on the survival of Epichloë lolii in perennial ryegrass seeds, demonstrating that low temperatures and low humidity are optimal for long-term endophyte viability. Hume et al. [23] also emphasize that controlling humidity and temperature during seed storage is decisive for maintaining endophyte viability, which is critical for endophyte-based breeding programs.
The research conducted in this study on endophyte viability in grass seeds, both before and after storage under controlled temperature conditions, demonstrates that temperature is a key factor, in addition to humidity, significantly affecting endophyte viability. Furthermore, even under the same temperature conditions, the decline in the viability of endophytic fungi varies depending on the grass species and cultivar examined. Similar observations were made by Welty and Azevedo [33], who indicated that in tall fescue seeds stored at humidity levels above 11.5% and temperatures above 5 °C, there is a rapid decline in endophyte viability. A reduction in endophyte viability during seed storage in warehouses was also observed by Shelby and Dalrymple [34]. Consistent with other studies, storing grass seeds under ambient conditions can reduce endophyte mycelial viability to zero after approximately 18–24 months [35]. Conversely, reducing air humidity to around 20–30% and temperature to a few degrees above 0 °C can significantly extend endophyte viability while also ensuring good seed germination [20,36,37].
In the present study, interesting observations were made for perennial ryegrass cv. Vigor, in which compared to the other tested species, no decrease in endophyte viability was found, regardless of storage conditions. Hume et al. [38] indicate in their work that Epichloë endophyte associations with Festuca species are generally less resilient in terms of endophyte viability during storage compared to associations with Lolium perenne.
However, this phenomenon is complex and results from the interaction of many factors, including specific characteristics of the host grass species, such as seed biochemical composition and structure, which influence the internal microenvironment [39]. Equally important are endophyte strain-specific factors, such as its inherent resistance to storage-related stresses and dormancy physiology [38]. Oliveira and Castro [40] emphasize that seeds should be stored under conditions that allow for the preservation of symbiont viability, and subsequent harvests should be handled in a way that preserves endophyte viability for as long as possible. One way to maintain viability might be to shorten the storage time between successive propagations, although this is associated with increased costs.
It is worth noting that research on maintaining endophyte viability is not limited to forage grasses but is also of great importance for turf grasses to which these fungi bring many benefits, such as increased resistance to environmental stresses and diseases, leading to better turf quality and durability [41,42]. Understanding and applying optimal storage conditions for endophyte-infected seeds is therefore crucial for a wide range of applications in agriculture and horticulture.
Another important aspect related to the transmission of endophytes through seeds is the possibility of eliminating the mycelium from seeds and plants. This aims to prevent the spread of these fungi in grasslands where their presence is undesirable, for example, due to the production of toxic alkaloids. Eliminating endophytic fungi from grass seeds is crucial in managing their presence, especially when they pose a risk of toxicity to livestock [43].
In the presented research, we focused on evaluating the feasibility of eliminating endophytic fungi in seeds using three selected methods, namely seed treatment, microwave radiation, and elevated temperatures. The results showed that each of the methods used was effective in at least partially eliminating endophytes from seeds. However, the highest efficacy was observed after applying the chemical seed treatment Raxil Gel®, which contains the active ingredients tebuconazole and thiram. These results confirm the observations of many authors working on these issues, yet the effectiveness of chemical seed treatments is closely related to the type of active substance used [19,25,44]. Moreover, the efficacy of seed treatment varies depending on the specific endophyte–host association. For example, Epichloë coenophiala, which colonizes tall fescue, exhibits high sensitivity to various triazole fungicides [19], whereas Epichloë lolii, found in perennial ryegrass plants, is most effectively controlled by compounds like prochloraz and propiconazole [17,45]. Studies by Siegel et al. [18] showed that fungicides, especially benzimidazole and ergosterol synthesis inhibitors, are effective in inhibiting the development of these fungi under laboratory conditions. These fungicides were also used for spraying plants and soil in greenhouse experiments [17]. However, none of the fungicides used yielded satisfactory results under field conditions, indicating the limitations of this method in agricultural practice. Both Latch and Christensen [17] and Siegel et al. [18] agree that eliminating endophytes from seeds using fungicides or physical methods (e.g., high temperature) appears to be more effective than spraying plants. The short-term exposure of perennial ryegrass and tall fescue seeds to high temperatures can kill endophytes, but this often leads to a simultaneous reduction in the germination capacity of these seeds [18]. This presents a significant challenge, as the goal is to eliminate endophytes without harming seed viability.
Attempts have also been made to remove endophytes that produce animal-toxic alkaloids from seeds while simultaneously infecting them with Epichloë isolates that produce alkaloids harmless to animals, such as peramine [46]. However, such approaches, aiming to replace “undesirable” endophytes with “desirable” ones, have encountered significant problems, particularly related to maintaining a stable endophyte–host association under field conditions. More effective and safer methods for endophyte elimination are still being sought. Kirkby et al. [29] investigated the effect of hydrothermal treatments on seeds, aiming to optimize temperature and exposure time to minimize seed damage while maximizing endophyte elimination. Recently, research into biological control methods, such as the use of antagonistic microorganisms, has received importance as an alternative to chemical agents [47]. The development of innovative approaches that are both effective and environmentally friendly remains a priority in managing grass endophytes.
It should be noted, however, that not all endophyte elimination methods are easy to apply on an industrial scale due to technical difficulties. Furthermore, Kirfman et al. [48] suggest that eliminating endophytic fungi from grasslands could potentially disrupt the biological balance, leading to an increase in the incidence of some insects and pests and a decrease in others. This highlights the complexity of decisions regarding endophyte elimination and the need for a balanced approach.
In the European context, Cappelli and Buonaurio [49] emphasize that to prevent the spread of endophyte infection in grasses, seed reproduction covered by national evaluation programs must utilize sensitive and rapid methods for detecting endophytes in seeds, including the parental materials of cultivars. In some countries, such as France, a ban on the registration and trade of seed cultivars containing endophytes has already been introduced [50]. An alternative strategy, indicated by Latch and Christensen [17], is to obtain endophyte-free planting material by breeding parent plants that are naturally not colonized by these fungi.

5. Conclusions

The viability of Epichloë endophytes in stored seeds shows significant genotypic variability, being closely linked to the species and cultivar of the host plant. Observations indicate that symbiotic Epichloë fungi in association with Festuca species (e.g., Festuca arundinacea) typically exhibit lower long-term viability compared to those in symbiosis with perennial ryegrass. The initial viability of the endophyte population is crucial for its ability to withstand later challenges during storage.
The optimum range of temperatures for maintaining endophyte viability in seeds was identified. Maintaining low temperatures significantly extends the survival period of the fungus in seeds. However, extremely low temperatures can negatively affect endophyte viability, suggesting the existence of an optimal temperature range.
In the context of obtaining endophyte-free planting material, chemical methods, especially seed treatment with systemic fungicides, prove to be the most effective in eliminating the Epichloë mycelium. Other strategies, including non-chemical methods, while potentially leading to a partial reduction in infection levels, usually do not guarantee complete elimination of the fungus from seeds.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/agronomy15081977/s1, Table S1. Germination capacity of seeds of the tested grass species and varieties after storage in three different environmental conditions. Table S2. Germination capacity of seeds of the tested species and varieties after applying three different methods of eliminating endophytes from seeds.

Author Contributions

Conceptualization, B.W. and G.Ż.; methodology, B.W.; formal analysis, B.W. and G.Ż.; investigation, B.W. and G.Ż.; resources, B.W. and G.Ż.; data curation, G.Ż.; writing—original draft preparation, B.W. and G.Ż.; writing—review and editing, B.W. and G.Ż.; visualization, G.Ż. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors upon request.

Conflicts of Interest

The authors declare no conflicts of interest.

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Agronomy 15 01977 g001
Figure 1. Hyphae of Epichloë sp. associated with aleurone layer in seeds.
Figure 1. Hyphae of Epichloë sp. associated with aleurone layer in seeds.
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Figure 2. Epichloë endophyte viability in grass seeds under different storage conditions. Bars indicate standard error of means. Description of storage conditions: control—initial endophyte viability; S_1—variable temperature, average +23 ± 5 °C, variable humidity (56 ± 5%); S_2—stable temperature +7 °C, stable humidity 55%; S_3—stable temperature −20 °C, stable humidity 10%.
Figure 2. Epichloë endophyte viability in grass seeds under different storage conditions. Bars indicate standard error of means. Description of storage conditions: control—initial endophyte viability; S_1—variable temperature, average +23 ± 5 °C, variable humidity (56 ± 5%); S_2—stable temperature +7 °C, stable humidity 55%; S_3—stable temperature −20 °C, stable humidity 10%.
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Figure 3. Endophyte viability after application of selected elimination methods. Bars indicate standard deviation of means. Description of elimination methods: control—initial endophyte viability; dried—storing seeds in a forced air circulation laboratory drying oven at 38 °C and 50% humidity for 5 days; microwaved—exposing seeds to microwave radiation at 90 W for 10 min; seed treatment—applying seed treatment Raxil Gel®.
Figure 3. Endophyte viability after application of selected elimination methods. Bars indicate standard deviation of means. Description of elimination methods: control—initial endophyte viability; dried—storing seeds in a forced air circulation laboratory drying oven at 38 °C and 50% humidity for 5 days; microwaved—exposing seeds to microwave radiation at 90 W for 10 min; seed treatment—applying seed treatment Raxil Gel®.
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Table 1. Results of two-way ANOVA on the effect of cultivars and seed storage conditions of endophyte viability.
Table 1. Results of two-way ANOVA on the effect of cultivars and seed storage conditions of endophyte viability.
Sources of VariationResults of Analysis
MSF-Calc.p
cultivar (n = 7)6484.46505.70.000
storage condition (n = 4)3069.00239.40.000
interaction (n = 28)215.4216.80.000
error12.82
Table 2. Results of two-way ANOVA on the effect of cultivars and endophyte elimination methods on endophyte viability.
Table 2. Results of two-way ANOVA on the effect of cultivars and endophyte elimination methods on endophyte viability.
Sources of VariationResults of Analysis
MSF-Calc.p
cultivar (n = 7)3991.96469.60.000
elimination method (n = 4)20,521.142414.30.000
interaction (n = 28)670.0678.80.000
error8.5
Table 3. Results of Pearson’s correlation coefficients calculated for initial endophyte viability and viability recorded after treatments applied.
Table 3. Results of Pearson’s correlation coefficients calculated for initial endophyte viability and viability recorded after treatments applied.
Endophytes Exposed toConditions/Treatments AppliedCorrelation Coefficients with Initial (Control) Viability
seed storage+23 °C0.80 ***
+7 °C0.89 ***
−20 °C0.76 ***
eliminationdryer0.71 ***
microwave0.87 ***
Raxil Gelnd.
Explanation: significance of correlation coefficients: ***—significant with probability higher than 99%, nd—no data (not calculated).
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Wiewióra, B.; Żurek, G. Endophyte Viability in Grass Seeds: Storage Conditions Affecting Survival and Control Methods. Agronomy 2025, 15, 1977. https://doi.org/10.3390/agronomy15081977

AMA Style

Wiewióra B, Żurek G. Endophyte Viability in Grass Seeds: Storage Conditions Affecting Survival and Control Methods. Agronomy. 2025; 15(8):1977. https://doi.org/10.3390/agronomy15081977

Chicago/Turabian Style

Wiewióra, Barbara, and Grzegorz Żurek. 2025. "Endophyte Viability in Grass Seeds: Storage Conditions Affecting Survival and Control Methods" Agronomy 15, no. 8: 1977. https://doi.org/10.3390/agronomy15081977

APA Style

Wiewióra, B., & Żurek, G. (2025). Endophyte Viability in Grass Seeds: Storage Conditions Affecting Survival and Control Methods. Agronomy, 15(8), 1977. https://doi.org/10.3390/agronomy15081977

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