Research article | Open Access
Helia 2021, Vol. 44(75) 181-190
pp. 181 - 190
Publish Date: December 01, 2021 | Single/Total View: 7/18 | Single/Total Download: 8/21
Abstract
The effects of various concentrations of herbicide Euro-Lightning Plus on the state of microbiota in the root zone of sunflower have been studied. Soil of plant rhizosphere and interrow soil after treatment with the herbicide at the doses of 1.2 and 2.5 l/ha were taken for the analysis at the end of sunflower growing season. Rhizosphere soil without herbicide application was used as a control. The herbicide was applied at the stage of 2'4 true leaves. The total number of bacteria in the rhizosphere of control plants was 12.82 million CFU/g of soil while in the rhizosphere and in the interrow soil after herbicide treatment with a dose of 2.5 l/ha it decreased by 1.4'1.5 times. A general trend of decline in number of the basic ecological and trophic groups of bacterial microorganisms with the increase in a dose of herbicide was established. Microbiological coefficients that reflect the functional activity of the microflora indicate changes in its biological activity under the influence of the herbicide Euro-Lightning Plus which leads to deterioration in the agroecological state of the studied soils. It was also found that herbicide application resulted in a rearrangement of micromycete complexes in the root zone of sunflower which led to a two-fold reduction compared to the control of mycobiota species diversity and the formation of a specific species composition of mycocenoses. A greater genus and species diversity of fungi of the microflora in the rhizosphere of control plants in comparison with the herbicide-treated soil was revealed. A reduction in species diversity of the genus Penicillium from six species in the control to 1'2 species in the rhizosphere of experimental sunflower plants as well as the absence of rare saprophytic fungi species from the genera Acremonium Verticillium Trichoderma and Paecilomyces were noted. ut a clear 'unique' explanation for it. The erratic appearance of the phenomena has led to consider it either a disease or hybrid defect and the plants with Phyllody as off-types raising several farmers claims to seed producers. However the auxins gradient in the growing Asteraceae heads determines the differentiation pathway of the undifferentiated cells. i.e. bracts and ray flowers at the border and disk flowers in the centre of the head. Disruption of the natural auxin gradient alters the cell differentiation in the growing heads and causes bracts and ray flowers to grow where only disk flowers should grow. The disruption of the natural head bottom auxin gradients may be caused by small injures in the fast-growing head receptacle. The most common causes of Phyllody are hormonal herbicide damage and Boron (B) deficiency even temporary. Plants growing with B deficiency have brittle cell wall and membranes while a plant with high B levels produces plastic or elastic cell wall and membranes. Brittle cell walls are susceptible to breaks during growth. Sunflowers genotypes may react to crack or small damages in the sunflower bud in two ways. Some tend to repair the damages by regrowing new organs such as ligules or bracts and forming Phyllody. Others do not regrow and only heal the wound creating the funnel hole head shape.
Keywords: herbicide; microbial complex; mycocenosis; root zone; sunflower
APA 7th edition
Soroka, N.K.V.L.A. (2021). The state of soil microbiotes during sunflower growing with an herbicide of imidazolinone group. Helia, 44(75), 181-190.
Harvard
Soroka, N. (2021). The state of soil microbiotes during sunflower growing with an herbicide of imidazolinone group. Helia, 44(75), pp. 181-190.
Chicago 16th edition
Soroka, Natalia Kostyuchenko Viktor Lyakh Anatoliy (2021). "The state of soil microbiotes during sunflower growing with an herbicide of imidazolinone group". Helia 44 (75):181-190.