REV.CHIM.(Bucharest) ♦70♦No. 11 ♦2019 http://www.revistadechimie.ro 3913 Isolation and Cultivation of Some Pathogen Fungi from Apple and Grapevines Grown in Arges County CAMELIA UNGUREANU 1 , MIRELA CALINESCU 2 *, MARIANA FERDES 1 , LILIANA SOARE 3 , DIANA VIZITIU 4 , IRINA FIERASCU 5 , RADU CLAUDIU FIERASCU 5 , SILVIU RAILEANU 1 1 University Politehnica of Bucharest, 313 Splaiul Independentei Str., 060042, Bucharest, Romania 2 Research Institute for Fruit Growing Pitesti - Maracineni, 402, Marului Str., Arges, 110006, Romania 3 University of Pitesti, 1 Targul din Vale Str., 110040, Pitesti, Romania 4 National Research and Development Institute for Biotechnology in Horticulture Stefanesti Arges, 37 Bucharest - Pitesti Str., 117715, Arges, Romania 5 The National Institute for Research & Development in Chemistry and Petrochemistry, ICECHIM, 202 Spl. Independentei, 060021, Bucharest, Romania The development of apple and grapevines varieties displaying durable resistance against some disease is one of the major aims in breeding programmes worldwide. In order to test some bio fungicides, the isolation of some pathogens for apple (Podosphaera leucotricha, Venturia inaequalis) and grapevine (Plasmopara viticola) was carried out. Keywords: Apple scab, powdery mildew, Podosphaera leucotricha, Plasmopara viticola, Venturia inaequalis In a last decade, in modern agriculture, fungicides play a major role in maintaining crop health and reliable yields of agriculture products. Recently, in Arges County, Romania, 45° 0’ 0” N, 24° 49’ 12”, diseases occurring in fruit trees (apple, pear, peach, apricot, etc.) and vines are more common and very virulent than a few years ago. Explanations would be climate change that leads to increased rainfall, humidity and wind direction, but also to excess or unilateral application of nitrogen fertilizers. Also, the resistance of pathogenic germs to the multitude of synthetic treatments is a cause [1-2]. Plasmopara viticola (fam. Peronosporaceae, ord. Oomycetales, cl. Phycomycetes) is the causal agent of grapevine downy mildew and was introduced into Europe in 1878; is considered as one of the most important grape pathogens worldwide [3]. Apple powdery mildew (APM) is a destructive pathogen, it produces damages in fruit and leaves. Plasmopara viticola is the fungus, very common in our country, which can lead to production losses of up to even 80 %. As early as spring, resistance spores germinate at the surface of wet soil at temperatures above 10 o C (the optimum being 23-24 o C) and from the inside a mycelian filament grows that falls on the ground. The spores thus formed arrive during the rains on the leaves (the inner part) where they penetrate the tissues of the plant producing the infection. At this moment yellow spots appear on the leaves because Plasmopara viticola begins the vegetative period in the leaf. The disease itself leads to the appearance of a white soft layer that carries the spores (viable for 7-8 days) and represents the mycelium. They penetrate the leaves through the stomata, being much better drained when they also have moisture from the rain. In autumn the secondary contamination occurs when the cycle closes, forming again resistant spores which germinate again in the spring. It is very important to drain the soils that strongly retain the water and destroy the leaves and grass around the plantations and / or realize deep excavations. Fruits can be attacked after they reach a surface of 10- 25 cm² until they get old and have various aspects starting from a yellow aspect in spring to a brown aspect in autumn *e m a il: elacalinescu@yahoo.com; Phone:+ 40721640727 (dry and burned aspect). On the back of the leaves appears a whitish layer representing the fungus mycelium and spores. The attack on sprouts manifests itself through the appearance of some brown spots that during rainy weather is covered with a whitish layer composed of mycelium spores. The vine strings thus attacked no longer reach maturity. In the very rainy years, young resins suffer the most and lead to dramatic decline in production. During autumn, Plasmopara viticola, forms resistance organs that germinate again in spring [4-6]. Podosphaera leucotricha f.c oidium farinosum is the fungus responsible with the powdery mildew disease . This disease occurs from debuding and continues until leaves fall during autumn, with an increased progression in May- June. In the mildew case flowers, leaves, sprouts and even young fruits are affected. The disease manifests itself in the form of a whitish flour (dust) covering all the above listed categories and leads to their early drying. Podosphaera leucotricha covers the sprouts with a whitish mycelium layer in the form of powder / flour when the spores are formed and in autumn this powder becomes brown at the time of fungus fructification. The most sensible variety of apple which is exposed to the mildew process is the Jonathan on whose leaves appears a fine mesh of brown tissue. In winter, this pathogen in the form of a resistance mycelium grows between the scales of spring buds that form sprouts, leaves, flowers that are the first sources of infection. Thus, as the first prevention and control measure, it is recommended that the severely affected sprouts be cut and destroyed by burning [7-8]. In addition to powdery mildew disease, the apple scab disease is also a very aggressive disease that attacks apple species. Venturia inaequalis is the microorganism responsible for this disease that attacks all the aerial parts of the tree, especially leaves and fruits. On leaves it appears on their backs in the form of gray spots that become brown as they grow and on flowers it appears on sepals. On the fruit appear the same gray spots that can grow and are gateways for other diseases and microorganisms. A scab resistant apple breed is the Florina species [9-10]. Due to of multiple benefits for human health [ 11] , disease prevention of apple has attracted significant attention in the scientific field .