Effect of Fusarium infection on wheat quality parameters

Wheat is one of the most important cereal grains; it provides carbohydrate staple foods that form the basis of most diets around the world. Wheat production is endangered by Fusariumspecies which cause Fusarium head blight. Fusarium head blight is one of the most devastating diseases of small grain cereals. This disease not only causes grain yield losses, but also decreases wheat quality and causes the presence of harmful mycotoxins. The experiment was conducted during two growing seasons 2020 and 2021 at the experimental field and laboratories of the Hungarian University of Agriculture and Life Sciences (MATE). The aim of our study is to test the effect of Fusarium infection on wheat quality parameters. The wheat variety used in the experiment is Mv Kolompos. The results indicate that Fusarium infection in 2021 (94%) is higher than in 2020 (48.4%). The increase in Fusarium infection reduces wheat quality. Hence, it negatively affects protein content, test weight, thousand kernel weight, falling number, gluten content and Zeleny sedimentation index. The higher the Fusarium infection the lower the value of wheat quality parameters.


Introduction
Cereals have been a basic agricultural product since ancient times due to their nutritional properties, moderate cost and ability to achieve immediate satiation. Wheat is a plant grown on more land area than any other commercial crop. Wheat provides carbohydrate staple foods that form the basis of most diets, both ancient and modern, around the world (Jones et al. 2015). Wheat flour is used in a diverse range of end use products including bread, cake, noodle, cracker, cookie, and pasta (Khan 2019). Wheat kernel is composed of endosperm (81-84%), bran (14-16%) and germ (2-3%). The endosperm is rich in carbohydrate, lipid and protein (Hung 2016). The bran is the outer layer protecting the kernel. The germ is the kernel's embryo that will grow into a new plant (Shewry 2004).
Wheat production is endangered by Fusarium species which cause Fusarium head blight (FHB). Fusarium head blight (FHB) is one of the most devastating diseases of small grain cereals. The dominant fungal agent associated with this disease on wheat is Fusarium graminearum (Schwabe), the anamorph of Gibberella zeae (Schwabe) Petch (Kikot et al. 2011). During the flowering period when the weather conditions are favorable Fusarium infection will start in the middle of the wheat spikelet and expand within the whole head, leading to bleached spikes and lightweight shriveled kernels (Kelly et al. 2015). This disease not only causes grain yield losses, but also decreases wheat quality and causes the presence of mycotoxins in the grains which are harmful to human and animal health (McMullen et al. 2012;Gärtner et al. 2008).
Crop losses due to FHB represent a significant problem worldwide (Mesterházy et al. 2020). FHB reduces yield and quality of grains, as it is manifested in their weight loss, carbohydrate and protein composition changes and the presence of fungal toxins (Magliano and Kikot 2013). It can destroy starch granules, storage proteins, and grain cell wall and subsequently affect the quality of wheat flour (Dexter et al. 1997). Nightingale et al. (1999) showed that the consistency and resistance to extension of dough was decreased when Fusarium damaged grains were included in the flour constituents. This resulted in substantial reductions in loaf volume and was attributed to the presence of fungal proteases. Fungal proteases have been shown to lead to weak dough properties and unsatisfactory bread quality (Wang et al. 2005). Additionally, Fusarium infection reduces gluten strength in wheat due to lower proportions of glutenin (Dexter et al. 1997). Consequently, FHB infection results in the reduction of end use quality (Dexter and Nowicki 2003). The most important method for FHB control and the reduction of mycotoxin concentration is the use of FHB resistant wheat varieties, appropriate cultural practices, fungicides, biological control and crop rotation (Mesterházy et al. 2015).
Previous studies reported the effect of fertilization (Horváth 2015; Kismányoky and Ragasits 2005;Pepó 2007;Salgó and Gergely 2012), storage time (Móré et al. 2014) and transgenic plant (Rakszegi et al. 2005) on wheat quality. Research on the impact of Fusarium infestation on wheat quality is scarce (Spanic et al. 2021). Hence, the aim of this research is to study the effect of Fusarium infection on wheat quality parameters: falling number, protein and gluten content, test weight, thousand kernel weight and Zeleny sedimentation index.

Materials and methods
The experiment was conducted during two growing seasons 2020 and 2021 at the experimental field and laboratories of the Hungarian University of Agriculture and Life Sciences (MATE), Crop Production Institute, Gödöllő, Hungary. The experimental site is in a hilly area with a close to average climatic zone of the country (47° 35′ 40.8″ N 19° 22′ 08.4″ E, 210 m above sea level). The soil type of the experimental field is brown forest soil (Chromic Luvisol). Prior to sowing, the field was cleared, ploughed, rotor-tilled and the seedbed was prepared. The plots were sown and harvested with plot machines. The wheat variety used in this experiment was Mv Kolompos. The plot area was 75 m 2 divided in 15 sampling areas of 5 m 2 each. At the end of each growing season, a wheat kernel sample was taken from each sampling area to measure Fusarium infection, protein content, gluten content, test weight, thousand kernel weight, falling number and Zeleny sedimentation index. Fusarium infection percentage was calculated by counting the number of colonies that formed on wheat kernels disinfected with a solution of PCNB and chloramphenicol (100 kernels from each sample) incubated for 7 days under laboratory conditions on Nash and Snider Fusarium selective medium (Distilled water 1 l, Peptone 15 g, KH 2 PO 4 1 g, MgSO 4 7H 2 O 0.5 g, Agar 20 g, PCNB 1 g, Chloramphenicol 100 ppm). Protein content, gluten content and Zeleny sedimentation index were measured by Mininfra Scan-T Plus 2.02 version.
Falling number was measured by ICC method No. 107/1 1995. The OS 1 type equipment by the ISO 7971-3:2019 standard was used to measure test weight. Thousand kernel weight and test weight were measured with the KERN EMS and the Sartorius MA-30 precision scales. IBM SPSS V.21 software was used for the statistical evaluation of the results, the linear regression module at 5% significance level was performed to determine the effect of Fusarium infection on wheat quality parameters, and the analysis of variance (ANOVA) module at 5% significance level was performed to determine the effect of the year on Fusarium infection and wheat quality parameters.
Simple linear regression is used to test if Fusarium infection in 2020 and 2021 growing seasons significantly predicts the following wheat quality parameters: protein content, test weight, thousand kernel weight, falling number, gluten content, and Zeleny sedimentation index.

Discussion
The present study was carried out to determine the effect of Fusarium infection on wheat quality in 2020 and 2021 growing seasons. The different climatic conditions that prevailed during 2020 and 2021 growing seasons could be the reason for the increase in Fusarium infection which leads to the decrease in wheat quality. According to El Chami et al. (2022), climatic factors play a key role in determining fungal occurrence. Thus, the activity of the fungi and their level of colonization are much determined by environmental conditions. In our study the increase in Fusarium infection showed a negative impact on wheat quality. Antes et al. (2001) and Prange et al. (2005) found that a strong Fusarium infection did not significantly influence wheat quality parameters. On the contrary, Gärtner et al. (2008) and Seitz et al. (1986) observed in their studies that Fusarium infection has negative effects on wheat quality parameters. The results obtained showed that Fusarium infection decreases protein     and gluten content. Dexter et al. (1997) and Gärtner et al. (2008) observed in their research a slight decrease in protein and gluten content in wheat kernels after Fusarium infection. Wang et al. (2005) concluded that protein and gluten content in the wheat grain were not affected by Fusarium infection. However, Boyacioğlu and Hettiarachchy (1995) concluded that protein and gluten content in wheat kernels increased following their contamination with Fusarium species. The results obtained revealed that Zeleny sedimentation index and falling number were significantly reduced by Fusarium infection. Papousková et al. (2011) observed that Zeleny sedimentation index and falling number showed distinctively decreased values in the infected samples. Meyer et al. (1986) and Gärtner et al. (2008) observed general reduction of Zeleny sedimentation index in wheat grains after Fusarium infection. According to Hareland (2003), Fusarium infection increases the degradation of starch in wheat kernels due to the presence of enzymes such as α-amylase which in turn decreases the quality of wheat flour and results in lower falling number values. The results obtained indicated that test weight and thousand kernel weight were significantly decreased by Fusarium infection. Test weight is primarily a function of the size of the grains. The fact that Fusarium infection affects test weight has been well documented (McMullen et al. 2012;Wong et al. 1995). Spanic et al. (2017) findings suggest that Fusarium infection has a negative effect on test weight. Dexter et al. (1996), Wang et al. (2005) and Dvojkovic et al. (2007) found that Fusarium infection resulted in a decrease of thousand kernel weight. Fusarium infected kernels are damaged, shriveled, shrunken and light weight showing a tendency towards a decrease in the endosperm to bran ratio due to fungal carbohydrate consumption. Results from the mentioned studies indicate that Fusarium infection may alter and lead to the deterioration of wheat quality parameters.

Conclusion
The results indicate that Fusarium infection in 2021 (94%) is higher than in 2020 (48.4%). The increase in Fusarium infection reduces wheat quality. Hence, it negatively affects protein content, test weight, thousand kernel weight, falling number, gluten content and Zeleny sedimentation index. The higher the Fusarium infection the lower the value of wheat quality parameters.