Global warming reduces surface water and dries out soils thus affecting wheat production by decreasing its grain yield and quality. Therefore, for ensuring global food security it is important to ...enhance drought tolerance in wheat. In this context, the alleviating effects of Silicon (Si) on drought stress has been observed in wheat. It has been reported that Si is also involved in physiological functions of wheat where it may improve antioxidant defense. Accordingly, Si fertilization could provide a relatively cheap method of improving wheat drought tolerance although Si is the second most abundant element, it is not readily available for uptake by plants. This study provides an overview of the currently available information on Si-mediated defense responses under drought stress.
Globalno zatopljenje smanjuje površinsku vodu i isušuje tlo što utječe na proizvodnju pšenice smanjujući urod i kvalitetu zrna. Stoga je za osiguranje svjetske proizvodnje hrane važno povećati otpornost pšenice na sušu. U tom kontekstu, ublažavajući učinci silicija (Si) na sušni stres zabilježeni su u pšenici. Zabilježeno je da je Si također uključen u fiziološke procese u pšenici gdje može poboljšati antioksidacijsku obranu. U skladu s tim, gnojidba silicijem mogla bi pružiti relativno jeftinu metodu poboljšanja tolerancije pšenice na sušu, iako je silicij drugi najzastupljeniji element, nije lako dostupan za unos u biljke. Ovaj pregledni rad daje uvid u trenutno dostupne informacije o Si-posredovanim obrambenim odgovorima na sušni stres.
Breeding resistant wheat cultivars to Fusarium head blight (FHB), caused by
spp., is the best method for controlling the disease. The aim of this study was to estimate general combining ability (GCA) ...and specific combining ability (SCA) for FHB resistance in a set of eight genetically diverse winter wheat cultivars to identify potential donors of FHB resistance for crossing. FHB resistance of parents and F1 crosses produced by the half diallel scheme was evaluated under the conditions of artificial inoculation with
and natural infection. Four FHB related traits were assessed: visual rating index (VRI), Fusarium damaged kernels (FDK), and deoxynivalenol and zearalenone content in the harvested grain samples. Significant GCA effects for FHB resistance were observed for the parental cultivars with high FHB resistance for all studied FHB resistance related traits. The significant SCA and mid-parent heterosis effects for FHB resistance were rare under both artificial inoculation and natural infection conditions and involved crosses between parents with low FHB resistance. A significant negative correlation between grain yield under natural conditions and VRI (r = -0.43) and FDK (r = -0.47) under conditions of artificial inoculation was observed in the set of the studied F1 crosses. Some crosses showed high yield and high FHB resistance, indicating that breeding of FHB resistant genotypes could be performed without yield penalty. These crosses involved resistant cultivars with significant GCA effects for FHB resistance indicating that that they could be used as good donors of FHB resistance.
Wheat infections caused by Fusarium represent a global agricultural problem that reduces grain yield and negatively impacts wheat’s technological and rheological quality. Although fungal proteases or ...an increase in endogenous proteases due to Fusarium infection could negatively influence wheat storage proteins and dough performance, little research has been performed on either of these topics. The primary objective of this study was to identify the effect of Fusarium infection on protease activity in 25 wheat cultivars grown in two distinct locations in eastern Croatia. Apart from proteolytic activity, this paper describes the impact of Fusarium head blight (FHB) infection on the technological quality parameters of wheat flour and the dough’s rheological properties. The first treatment consisted of naturally grown, healthy wheat without fungicides, while the second treatment utilized wheat varieties subjected to intense FHB infection. Protein and wet gluten content in wheat grain and flour of uninfected cultivars were heavily influenced by testing location, soil type, and quality. Fusarium infection increased the activity of nonspecific proteases by 43% in flour samples from Osijek and 125% in flour samples from Tovarnik. Estimates of effect size showed that FHB infection had twice as big an effect on protease activity in Tovarnik as in Osijek, and a similar trend was found for dough softening. Moreover, the infection significantly impacted wheat cultivars’ extensograph values, indicating a lower resistance to stretching, extensibility, and total stretching energy in infected flour samples, indicating that dough functionality and volume loss can be attributed to exogenous fungal proteases. Still, the magnitude of the effect varied depending on the growth location and the cultivar’s traits. Multivariate data analysis identified three clusters of wheat cultivars, each with varying degrees of the Fusarium infection’s effects. Some cultivars displayed consistent protease activity and flour quality across sites. In contrast, others showed variability in their responses due to environmental conditions. To conclude, genetic resistance could provide adequate control of FHB, guaranteeing the successful protection of wheat quality. However, the possibility of confounding factors influencing genetic and cultivation conditions must be considered, and further research is needed to understand their interaction.
Due to climate change in recent years, there has been an increasing water deficit during the winter wheat sowing period. This study evaluated six Croatian winter wheat varieties' physiological, ...biochemical, and molecular responses under two drought stress levels at the germination/seedling growth stage. Lipid peroxidation was mainly induced under both drought stress treatments, while the antioxidative response was variety-specific. The most significant role in the antioxidative response had glutathione along with the ascorbate-glutathione pathway. Under drought stress, wheat seedlings responded in proline accumulation that was correlated with the
gene expression. Expression of genes encoding dehydrins (
,
) was highly induced under the drought stress in all varieties, while genes encoding transcription factors were differentially regulated. Expression of
was upregulated under severe drought stress in most varieties, while the expression of
was downregulated or revealed control levels. Different mechanisms were shown to contribute to the drought tolerance in different varieties, which was mainly associated with osmotic adjustment and dehydrins expression. Identifying different mechanisms in drought stress response would advance our understanding of the complex strategies contributing to wheat tolerance to drought in the early growth stage and could contribute to variety selection useful for developing new drought-tolerant varieties.
Improving wheat grain yield plays a significant role in ensuring global food security. Wheat production could be increased by the genetic improvement of wheat genotypes where delayed senescence with ...enhanced post‐anthesis capacity and staygreen traits could have an important role. In this study, chlorophyll a fluorescence (ChlF) rise kinetics from the early until late senescence of flag leaves, grain yield and other agro‐morphological characteristics were compared for three winter wheat advanced lines (Osk.4.312/10‐18, Osk.4.330/6‐18 and Osk.4.354/12‐18) under natural drought conditions. The differences between lines were observed when considering the heading date which was 1 and 4 days earlier for the line Osk.4.354/12‐18, than lines Osk.4.312/10‐18 and Osk.4.330/6‐18, respectively. Furthermore, line Osk.4.354/12‐18 had the highest test weight (kg hl−1), while line Osk.4.330/6‐18 showed a tendency of decreased grain yield, compared to the other two lines. Analysis of ChlF transients and several JIP‐test parameters indicated that all three lines had a generally similar course of changes in the photosynthetic performance of flag leaves during senescence under drought conditions. However, at the point when a decrease in photosynthetic performance was initiated, it was slightly less intensive in line Osk.4.354/12‐18 accompanied by longer preservation of functionality and connectivity of PSII units, than in the other two lines, which contributed to its better agronomical performance. These results indicated that even delicate variations in the functioning of the photosynthetic apparatus of the flag leaf during grain filling were agronomically important, especially when plants were exposed to drought stress, and could be used to differentiate otherwise similar wheat genotypes. Even small genotype‐specific differences in the photosynthetic performance of senescing flag leaves, along with earlier heading dates, could assist in the selection of genotypes with a better ability to cope with unfavourable environmental conditions.
Variations in the functioning of the photosynthetic apparatus of the flag leaf during grain filling can be agronomically important, especially when plants were exposed to drought, and could be used to differentiate otherwise similar wheat genotypes. Even small genotype‐specific differences in the photosynthetic performance of senescing flag leaves, slightly improved function of the photosynthetic apparatus, longer integrity of functional PSII units, and extended preservation of the optimal level of energetic connectivity among PSII units during grain filling, along with earlier heading dates, could assist in the selection of genotypes with a better ability to cope with unfavourable environmental conditions.
Wheat is one of the three most important cereals in the world, along with rice and maize. It serves as the primary food and source of energy for about 30–40% of the world’s population. However, the ...low levels of micronutrients in wheat grains can lead to deficiencies of those micronutrients in people whose dietary habits are mostly based on cereals such as wheat. Apart from iron (Fe) and zinc (Zn), a lack of selenium (Se) is also one of the biggest problems in the world. The essentiality of Se has been confirmed for all animals and humans, and the lack of this micronutrient can cause serious health issues. Wheat dominates the world’s cereal production, so it is one of the best plants for biofortification. Due to the fact that agronomic biofortification is not an economical or environmentally acceptable approach, genetic improvement of cereals such as wheat for the enhanced content of micronutrients in the grain represents the most efficient biofortification approach.
The application of dwarfing genes in wheat breeding effectively reduced plant height, improved lodging resistance and increased the harvest index. Although the gibberellin-responsive (GAR) dwarf gene ...Rht15 did not negatively affect coleoptile length or root traits while reducing the plant height, it reduced the yield plant−1. The gibberellin-insensitive (GAI) dwarf gene Rht1 can increase wheat yield under favorable conditions, but it reduces coleoptile length and affects root traits. This study was conducted to investigate whether the interaction of Rht15 and Rht1 can alleviate their negative effects. To analyze the interaction of Rht15 and Rht1, field experiments were conducted with the F5, F6 and F7 lines of the four genotypes, Rht15+Rht1, Rht15, Rht1 and tall lines detected using Rht15 and Rht1 molecular markers, derived from Durox (Rht15) and Kronos (Rht1), by comparing their effects on seedling traits, plant height and internode length, lodging resistance, flag leaf, yield and quality traits in durum wheat. The results showed that although the interaction of Rht15 and Rht1 did not overcome the inhibitory effect of Rht1 on coleoptile growth, it alleviated the negative effect of Rht1 on maximum root length (+14.8%). The grain yield plant−1 (+7.2%) of the Rht15 lines was improved under the action of Rht1 but was still lower than that of the Rht1 lines (−12.7%). The Rht15+Rht1 lines had the strongest effect on reducing plant height and center of gravity height (−42.2% and −41.5%), which significantly improved lodging resistance (+175%). The flag leaf area (+97.4%) and SPAD value (+11.6%, +9.6% and +10.6%) were also significantly increased. In addition, the coleoptile length of the Rht15 lines was not significantly different from that of the tall lines, the plant height and center of gravity height were significantly reduced (−30.5% and −34.0%), and the lodging resistance was significantly increased (+176.8%). The Rht1 lines had increased grain yield (+12.7%) due to an increased 1000-kernel weight (+12.9%) compared to the tall lines. In conclusion, the combination of Rht15 and Rht1 alleles enhanced the advantages and partially alleviated the defects in some traits when compared to the individual alleles, but the grain yield plant−1 was still lower than the Rht1 lines. This reflected the limitations of Rht15, and further confirmed the yield advantages of Rht1.
•Rht15 and Rht1 interacted to partially alleviate each other's defects in some traits.•Rht15 alleviated the negative effect of Rht1 on maximum root length.•The grain yield plant−1 of Rht15 lines have been improved under the action of Rht1.•Rht15+Rht1 lines did not achieve a good yield trait compared to the Rht1 lines.•Rht15+Rht1 lines improved lodging resistance by reducing plant height.
Fusarium head blight (FHB) is one of the most serious fungal diseases of wheat (Triticum aestivum L.). It causes major reduction of grain yield and quality, while the safety of wheat products is at ...risk due to mycotoxin contaminations. To contribute to a better understanding of mechanisms governing more efficient defense strategies against FHB, an evaluation of photosynthetic efficiency was performed during different phases of infection, i.e., before visual symptoms occur, at the onset and after the development of disease symptoms. Six different winter wheat varieties were artificially inoculated with the most significant causal agents of FHB (Fusarium graminearum and F. culmorum) at two different locations. Photosynthetic efficiency was assessed in flag leaves and ears of inoculated and untreated (control) plants based on measurements of chlorophyll a fluorescence rise kinetics and the calculation of JIP-test parameters. Obtained results indicate that the response of wheat to Fusarium infection includes changes in photosynthetic efficiency which can encompass alternating reductions and increases in photosynthetic performance during the course of the infection in both flag leaves and ears. FHB-induced photosynthetic adjustments were shown to be somewhat variety-specific, but location was shown to be a more significant factor in modulating the response of wheat to Fusarium infection. Changes in chlorophyll a fluorescence rise kinetics could be detected prior to visible symptoms of the disease. Therefore, this method could be applied for the early detection of Fusarium infection, particularly the analysis of L-band appearance, which showed a similar response in all inoculated plants, regardless of variety or location.
A Special Issue of Agronomy titled “Treatment and Management of Fusarium Disease in Wheat” published five articles addressing the resistance of winter wheat varieties/lines to Fusarium head blight ...(FHB) ...
Drought stress can significantly reduce wheat growth and development as well as grain yield. This study investigated morpho-physiological and hormonal (abscisic (ABA) and salicylic (SA) acids) ...responses of six winter wheat varieties during stem elongation and anthesis stage as well grain yield-related traits were measured after harvest. To examine drought response, plants were exposed to moderate non-lethal drought stress by withholding watering for 45 and 65% of the volumetric soil moisture content (VSMC) for 14 days at separate experiments for each of those two growth stages. During the stem elongation phase, ABA was increased, confirming the stress status of plants, and SA showed a tendency to increase, suggesting their role as stress hormones in the regulation of stress response, such as the increase in the number of leaves and tillers in drought stress conditions, and further keeping turgor pressure and osmotic adjustment in leaves. At the anthesis stage, heavier drought stress resulted in ABA accumulation in flag leaves that generated an integrated response of maturation, where ABA was not positively correlated with any of investigated traits. After harvest, the variety Bubnjar, followed by Pepeljuga and Anđelka, did not significantly decrease the number of grains per ear and 1000 kernel weight (except Anđelka) in drought treatments, thus, declaring them more tolerant to drought. On the other hand, Rujana, Fifi, and particularly Silvija experienced the highest reduction in grain yield-related traits, considering them drought-sensitive varieties.
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