جستجوی مقالات مرتبط با کلیدواژه « penicillium » در نشریات گروه « گیاهپزشکی »

The world's population is growing rapidly. To feed this large population, more crops must be produced. The broad use of fertilizers, pesticides and other inputs increases the productivity of existing agricultural lands and the amount of food production, but this increase in yield causes damage to the environment, soil degradation and the destruction of its natural microbial population. To prevent these harmful effects of the chemicals, an eco-friendly approach is needed to ensure human health and the environment. In the innovative view of agricultural production, there is a growing demand for the use of biofertilizers instead of agrochemicals. The use of beneficial microorganisms can be a new strategy to improve plant health and productivity. Natural microbial populations play an important role in the solubilizing and mineralizing of soil nutrients, which is very important for plant growth and development. Among the various microbial populations, fungi known as plants growth promoting fungi (PGPF) have recently received increasing attention. For decades, plant growth promoting fungi such as Trichoderma, Penicillium, Phoma, Aspergillus and Fusarium have been studied. Studies have shown that these fungi, regulate plant growth without environmental pollution and increase plant tolerance to plant pathogens. In this review a brief description of plant growth promoting fungi is given first. In the following, the nature and composition of these fungi as well as the mode of actions, formulation and related challenges will be concidered.

The province of Kohgiluyeh and Boyer-Ahmad in southwestern Iran is an important rice-growing area. Seed-borne fungi can cause harmful diseases, so identifying them is important to prevent these diseases.

Thirty seed samples of four rice varieties were collected from different regions of the province. Seed-borne fungi were isolated by using the potato-dextrose-agar plate, blotter, and deep freezing blotter methods and after purification, their morphological characteristics were studied and they were identified. The total frequency of seeds infected with fungi and the frequency of seeds infected with each fungus were calculated. The effect of these fungi on seed germination and root growth of four cultivars Champa, Shamim, Gerdeh, and Lenjan was tested by placing them between wet sterile filter papers.

Twenty-eight fungi of 11 genera vs. Alternaria, Aspergillus, Bipolaris, Cladosporium, Curvularia, Epicoccum, Fusarium, Penicillium, Pyrenophora, Rhizopus, and Ulocladium were identified in these thirty samples. These fungi did not significantly affect seed germination of these varieties, but caused root rot in them. The average infestation of the Champa variety was lower than the others.

The Champa variety is relatively resistant to these fungi, followed by Shamim, Lenjan, and Gerdeh respectively.

Plant diseases usually cause economic damage and reduce growth and crop yield.  Treatment of plant diseases with chemical toxins can result in environmental side effects, the emergence of resistance in pathogens, and loss of beneficial soil microorganisms, so the search for alternative methods such as identification and use of antagonistic microorganisms for disease treatment has been considered by researchers. A set of endophyte fungi that grow without damage or symptoms in host plant tissues and are known to be biological control agents of some plant diseases. Endophyte fungi with different mechanisms such as the production of antibiotic metabolites, competition, induction of resistance, and hyperparasitism of the pathogen weaken or eliminate the pathogens. These fungi can also help increase the growth and resistance of host plants to various stresses by producing antioxidant and antitumor compounds, as well as various growth hormones.

Apple postharvest diseases are usually caused by a wide range of pathogenic fungi. Postharvest rot of this crop is one of the most important economic diseases and also one of the main factors in reducing the lifespan of this crop. In contrast, our current knowledge of the occurrence and latent contamination during storage and its epidemiology is limited. The pathogenic fungi Botrytis cinerea and Penicillium expansum causing gray mold and blue mold, respectively, are the most common pathogens in the cultivation areas, which are usually inhibited by the use of synthetic fungicides. However, due to the growing concern over the use of synthetic fungicides, alternative control measures such as using physical treatments, natural compounds, and biocontrol agents are highly desired. Although no method has been approved as a definitive method of postharvest diseases management, the effectiveness of yeasts such as Candida saitoana, bacteria such as Rahnella aquatilis, and fungal species such as Trichoderma harzianum has been suggested.

The Fungi which are able to grow at the temperatures above 40 degrees Celsius are known as thermophilic fungi. So far, no study has been carried out on fungi in desert areas of Iran so the present study was aimed to isolate and identify the fungi in desert areas of Yazd province.

Four desert regions of Yazd province were visited and samples were taken from soil and plant roots. The fungi were isolated by soil dilution method and were cultured on potato-agar extract medium. Genus and species of fungi were identified by valid identification keys.

Eighteen fungi from eight genera vs. Aspergillus, Penicillium, Alternaria, Ulocladium, Stemphylium, Paecilomyces, Rhizopus and Fusarium were identified in this study.

The species of Penicillium and Aspergillus were the most abundant species in desert soils of this province. All fungi identified in this study are reported for the first time from Iranian desert soils.