The increase in the world population has generated an important need for both quality and quantity agricultural products, which has led to a significant surge in the use of chemical pesticides to ...fight crop diseases. Consumers, however, have become very concerned in recent years over the side effects of chemical fungicides on human health and the environment. As a result, research into alternative solutions to protect crops has been imposed and attracted wide attention from researchers worldwide. Among these alternatives, biological controls through beneficial microorganisms have gained considerable importance, whilst several biological control agents (BCAs) have been screened, among them
,
,
,
,
,
,
, and certain yeasts. At present, biopesticide products have been developed and marketed either to fight leaf diseases, root diseases, or fruit storage diseases. However, no positive correlation has been observed between the number of screened BCAs and available marketed products. Therefore, this review emphasizes the development of biofungicides products from screening to marketing and the problems that hinder their development. Finally, particular attention was given to the gaps observed in this sector and factors that hamper its development, particularly in terms of efficacy and legislation procedures.
Citrus trees face threats from several diseases that affect its production, in particular dry root rot (DRR). DRR is a multifactorial disease mainly attributed to
(
)
and other several species of
and
...spp. Nowadays, biological control holds a promising control strategy that showed its great potential as a reliable eco-friendly method for managing DRR disease. In the present study, antagonist rhizobacteria isolates were screened based on in vitro dual culture bioassay with
. Out of 210 bacterial isolates collected from citrus rhizosphere, twenty isolates were selected and identified to the species level based on the 16S rRNA gene. Molecular identification based on 16S rRNA gene revealed nine species belonging to
,
, and
genus. In addition, their possible mechanisms involved in biocontrol and plant growth promoting traits were also investigated. Results showed that pectinase, cellulose, and chitinase were produced by eighteen, sixteen, and eight bacterial isolates, respectively. All twenty isolates were able to produce amylase and protease, only four isolates produced hydrogen cyanide, fourteen isolates have solubilized tricalcium phosphate, and ten had the ability to produce indole-3-acetic acid (IAA). Surprisingly, antagonist bacteria differed substantially in their ability to produce antimicrobial substances such as bacillomycin (five isolates), iturin (ten isolates), fengycin (six isolates), surfactin (fourteen isolates), and bacteriocin (subtilosin A (six isolates)). Regarding the PGPR capabilities, an increase in the growth of the bacterial treated canola plants, used as a model plant, was observed. Interestingly, both bacterial isolates
K4-4 and GH3-8 appear to be more promising as biocontrol agents, since they completely suppressed the disease in greenhouse trials. Moreover, these antagonist bacteria could be used as bio-fertilizer for sustainable agriculture.
Phytophthora infestans
is the most devastating pathogen of potato. Considering the increasing demand for reducing inputs of synthetic and copper-based fungicides, and regarding the emergence of novel ...fungicide-resistant strains, alternative control methods are a necessity. The present review describes the features of
P. infestans
that make it such a daunting challenge to agriculture and summarizes the current literature regarding the biocontrol of the phytopathogenic
P. infestans
using antagonistic microorganisms. Several studies report the evaluation of
Trichoderma harzianum
,
Chaetomium globosum
,
Trichoderma viride
, yeasts, and bacteria from the genera
Bacillus
,
Pseudomonas
, and
Xenorhabdus
as biocontrol agents in the management of potato late blight disease. Overall, the results confirmed that some biosurfactants (such as surfactin and fengycin B) produced by isolates of
Bacillus
and
Pseudomonas
bacteria have a high efficiency effect to control the sporulation and release of
P. infestans
zoospores reaching a rate of 100%. Besides bacterial compounds, the combination of biological control agents with each other with compost or copper at low dose was very promising in the effective control of
P. infestans.
The present study is based on a multidisciplinary approach carried out for the first time on
var.
and
var.
, two varieties from the endemic and endangered medicinal species listed in the IUCN red ...list,
(L.) Link. Therefore, morphological, phytochemical, and genetic characterisations were carried out in the present work. Morphological characterisation was established based on 23 qualitative and quantitative characters describing the vegetative and floral parts. The phytochemical compounds were determined by UHPLC. Genetic characterisation of extracted DNA was subjected to PCR using two sets of universal primers, rbcL a-f/rbcL a-R and rpocL1-2/rpocL1-4, followed by sequencing analysis using the Sanger method. The results revealed a significant difference between the two varieties studied. Furthermore, phytochemical analysis of the studied extracts revealed a quantitative and qualitative variation in the chemical profile, as well as the presence of interesting compounds, including new compounds that have never been reported in
. The phylogenetic analysis of the DNA sequences indicated a similarity percentage of 91%. Based on the morphological characterisation and congruence with the phytochemical characterisation and molecular data, we can confirm that
var.
and
var.
represent two different taxa.
Flaxseed is an oilseed (45–50% oil on a dry-weight basis) crop. Its oil has demonstrated multiple health benefits and industrial applications. The goal of this research was to evaluate the ...antidiabetic and anti-inflammatory potential of the free polyphenol fraction of flax (Linum usitatissimum L.) seeds (PLU), based on their use in traditional medicine. Mice with alloxan-induced diabetes were used to study the antidiabetic activity of PLU in vivo, with an oral administration of 25 and 50 mg/kg over 28 days. Measurements of body weight and fasting blood glucose (FBG) were carried out weekly, and biochemical parameters were evaluated. An oral glucose tolerance test was also performed. Inhibitory activities of PLU on α-amylase and α-glucosidase activities were evaluated in vitro. The anti-inflammatory was evaluated in vivo in Wistar rats using the paw edema induction Test by carrageenan, and in vitro using the hemolysis ratio test. PLU administration to diabetic mice during the study period improved their body weight and FBG levels remarkably. In vitro inhibitory activity of digestive enzymes indicated that they may be involved in the proposed mode of action of PLU extract. Qualitative results of PLU revealed the presence of 18 polyphenols. These findings support daily consumption of flaxseed for people with diabetes, and suggest that polyphenols in flaxseed may serve as dietary supplements or novel phytomedicines to treat diabetes and its complications.
Cucurbits are among the most cultivated crops, and the most economically important species are melon (Cucumis melo L.), cucumber (Cucumis sativus L.), watermelon (Citrullus lanatus Thumb.), squash ...(Cucurbita pepo L.), and pumpkin (Cucurbita spp.). These crops have become important income sources providing export and local consumption commodities in many Mediterranean countries. Increased area of cucurbits has led to the emergence of several viral diseases, which can have impacts on crop production and threaten agricultural sustainability. An overview of the most damaging cucurbit viruses in the Mediterranean area is provided to improve understanding of the diseases they cause and to emphasize effective disease management strategies. An updating of the geographical distribution of these viruses, the symptoms they cause and their means of transmission is also provided. Disease management methods and measures by farmers and phytosanitary authorities to address the virus outbreaks are outlined, including diagnostics, use of tolerant cultivars, and chemical and biological vector control. Mediterranean region farmers have learned many lessons from the damaging pandemics caused by cucurbit viruses, through the extensive published research, and this review provides a basis for managing future outbreaks of newly emerging virus infections.
Grapevine trunk diseases (GTD) are currently one of the most devastating and challenging diseases in viticulture, leading to considerable yield losses and a remarkable decline in grapevine quality. ...The identification of the causal agents is the cornerstone of an efficient approach to fighting against fungal diseases in a sustainable, non-chemical manner. This review attempts to describe and expose the symptoms of each pathology related to GTD, the modes of transmission, and the harmfulness of recently reported agents. Special attention was given to new diagnostic tests and technologies, grapevine defense mechanisms, molecular mechanisms of endophytes fungal colonization, and management strategies used to control these threats. The present extended review is, therefore, an updated state-of-the-art report on the progress in the management of vineyards.
Monilinia fructigena is one of the most important fungal pathogens causing brown rot on apple and is heavily affecting fruit production. The main objective of this study was to screen for potential ...bacterial isolates with higher antagonistic activity against M. fructigena. Our study focused on the identification of potential bacterial isolates capable of reducing both the mycelial growth of M. fructigena and the disease severity using in vitro and in planta trials, respectively. To achieve this goal, thirteen bacteria, isolated from natural soil, were evaluated for their abilities to produce lytic enzymes (amylase, cellulase and protease), hydrocyanic acid (HCN) and lipopeptides (bacillomycin, fengycin, iturin and surfactin). Further, results from the dual culture method, volatile and bacterial free-cell filtrate bioassays indicated that tested isolates showed a fungicidal activity against the mycelial growth of M. fructigena. Thus, out of the 13 isolates tested, 12 exhibited significant mycelial inhibition (more than 70%) against M. fructigena, while remaining the last isolate displayed only a partial inhibition (up to 43%). Further, 12 of the bacteria isolates displayed an amylase production, 10 showed cellulase production, 11 revealed protease production, while only 2 displayed HCN production. In addition, most bacterial isolates were found to have genes encoding for different lipopeptides: bacillomycin (10), fengycin (3), iturin (11) and surfactin (1). Interestingly, two bacterial isolates, Bacillus amyloliquefaciens B10W10 and Pseudomonas sp. B11W11 were found to be the most effective and displayed the lowest disease severity in planta trial. These two bacteria reduced the brown rot incidence compared to the synthetic fungicide in a semi-commercial large-scale trial. Therefore, our findings suggest that these two later bacterial isolates provide apple protection against M. fructigena via direct and indirect mechanisms. These isolates may be used, therefore, as potential biological control agents (BCAs) in preventive treatment to control brown rot disease on apple fruits.
Locusts are known for their herbivorous diet that constitutes a nuisance to agriculture worldwide, in Morocco these insects are considered a real threat and are widely distributed in the country. ...These insects are equipped with a digestive system that allows them to digest huge amounts of plant tissue. To understand the mechanisms allowing this voracity, the current study has focused on the diversity of gut microbiome using biochemical and molecular analysis tools, different bacterial isolates were identified and studied. The present study results showed the presence of four important bacterial families that are present in the intestine of these insects, namely Micrococcaceae, Dermabacteraceae, Bacillaceae, and Pseudomonadaceae. The results of Gram staining showed that 2 of 11 isolates were Gram-negative bacteria, however, only 9 bacterial strains were catalase positive. While, 3 strains (
Pseudomonas stutzeri
S12,
Kocuria rhizophila,
and
Bacillus thuringiensis
S4 and S8) had pectinase activity, while only one strain (
Pseudomonas stutzeri
S12) had cellulase activity.
Sacc. is an ascomycete pathogen that causes
leaf spot in sugar beets (
L.) and other related crops. It can lead to significant yield losses if not effectively managed. This study aimed to assess ...rhizosphere bacteria from sugar beet soil as a biological control agent against
and evaluate their effect on
. Following a dual-culture screening, 18 bacteria exhibiting over 50% inhibition were selected, with 6 of them demonstrating more than 80% control. The bacteria were identified by sequencing the 16S rRNA gene, revealing 12 potential species belonging to 6 genera, including
, which was represented by 4 species. Additionally, the biochemical and molecular properties of the bacteria were characterized in depth, as well as plant growth promotion. PCR analysis of the genes responsible for producing antifungal metabolites revealed that 83%, 78%, 89%, and 56% of the selected bacteria possessed bacillomycin-, iturin-, fengycin-, and surfactin-encoding genes, respectively. Infrared spectroscopy analysis confirmed the presence of a lipopeptide structure in the bacterial supernatant filtrate. Subsequently, the bacteria were assessed for their effect on sugar beet plants in controlled conditions. The bacteria exhibited notable capabilities, promoting growth in both roots and shoots, resulting in significant increases in root length and weight and shoot length. A field experiment with four bacterial candidates demonstrated good performance against
compared to the difenoconazole fungicide. These bacteria played a significant role in disease control, achieving a maximum efficacy of 77.42%, slightly below the 88.51% efficacy attained with difenoconazole. Additional field trials are necessary to verify the protective and growth-promoting effects of these candidates, whether applied individually, combined in consortia, or integrated with chemical inputs in sugar beet crop production.
PDF
