A Survey of Five Plant Viruses in Weeds and Tobacco in Poland

Weeds may contribute to the spread of plant virus epidemics by acting as reservoirs of viruses or/and their vectors. The aim of this research was to study the prevalence of five viral pathogens in weeds in the fields of solanaceous crops in six provinces in Poland differing with soil and climate conditions. Most of the sampled sites were associated with tobacco production. The total number of 157 samples of tobacco and 600 samples of weeds were subjected to DAS-ELISA detection of tomato spotted wilt orthotospovirus (TSWV), cucumber mosaic virus (CMV), potato virus Y (PVY), tobacco mosaic virus (TMV) and tobacco ringspot virus (TRSV). Twenty nine percent of samples of weeds were infected with at least one virus. TSWV and TMV were the most frequently detected in 17.5% and 14.7% of samples, respectively. In most provinces where infected tobacco was found, the same virus was also detected in weeds. Results of this survey are discussed in the context of the current status of virus epidemics in tobacco fields in Poland

The Use of Carbohydrate Biopolymers in Plant Protection against Pathogenic Fungi

Fungal pathogens cause significant yield losses of many important crops worldwide. They are commonly controlled with fungicides which may have negative impact on human health and the environment. A more sustainable plant protection can be based on carbohydrate biopolymers because they are biodegradable and may act as antifungal compounds, effective elicitors or carriers of active ingredients. We reviewed recent applications of three common polysaccharides (chitosan, alginate and cellulose) to crop protection against pathogenic fungi. We distinguished treatments dedicated for seed sowing material, field applications and coating of harvested fruits and vegetables. All reviewed biopolymers were used in the three types of treatments, therefore they proved to be versatile resources for development of plant protection products. Antifungal activity of the obtained polymer formulations and coatings is often enhanced by addition of biocontrol microorganisms, preservatives, plant extracts and essential oils. Carbohydrate polymers can also be used for controlled-release of pesticides. Rapid development of nanotechnology resulted in creating new promising methods of crop protection using nanoparticles, nano-/micro-carriers and electrospun nanofibers. To summarize this review we outline advantages and disadvantages of using carbohydrate biopolymers in plant protection

The use of natural polymers for treatments enhancing sowing material

Biopolimery z grupy polisacharydów, dzięki swoim właściwościom fizykochemicznym, podatności na modyfikację chemiczną i biodegradację oraz wysoką bioaktywność, są wykorzystywane do uszlachetniania materiału siewnego roślin uprawnych. Polimery naturalne, takie jak: chitozan, alginian, celuloza, galaktoglukomannany, lignina oraz guma gellanowa mogą być stosowane jako substancje wiążące w otoczkowaniu nasion lub jako nośnik substancji aktywnych i mikroorganizmów. Biopolimery zawarte w otoczkach lub zaprawach nasiennych mogą ponadto przyczyniać się do ograniczenia niekorzystnego wpływu środowiska i patogenów na kiełkujące nasiona.Biopolymers from a group of polysaccharides are used in treatments enhancing sowing material of crops due to their physical and chemical properties, susceptibility to chemical modification, biodegradability and high bioactivity. Natural polymers, such as: chitosan, alginian, celulose, galaktoglucomannans, lignin and gellan gum, can be used as binders in seed coating or carriers of active substances and microorganisms. Moreover, biopolymers contained in the seed coatings and seed dressings can protect germinating seeds from unfavorable influence of environment and pathogens

Identification and Pathogenicity of <i>Fusarium</i> Isolated from Soybean in Poland

Fungi belonging to the Fusarium genus are commonly isolated from soybean plants and seeds but not all of them are pathogenic. The aim of this study was to compare the pathogenicity among different Fusarium isolates obtained from soybean plants with disease symptoms originating from an experimental field located in the southeast of Poland. Nineteen fungal isolates were selected for the pathogenicity assay, including eight isolates of F. oxysporum, six isolates of F. graminearum, four isolates of F. culmorum and one isolate of F. redolens. Species identification of these isolates was carried out using microscopic methods and sequencing of two genes: translation elongation factor 1-alpha (TEF1) and RNA polymerase second largest subunit (RPB2). To our knowledge, this is the first report of F. redolens being isolated from soybean in Europe. The pathogenicity test was set up by fungal inoculation of healthy soybean seeds of three cultivars: Abelina, Atlanta and Mavka. Symptoms were assessed seven days after inoculation. Disease area percentage of Fusarium inoculated seeds was significantly higher compared to uninoculated control. Nineteen isolates differed in their aggressiveness as the median disease area percentage ranged between 5.0 and 88.0% depending on isolate. The obtained isolates of four Fusarium species may be used in the future screening of soybean cultivars for resistance to these pathogens

Inheritance of Potato virus Y tolerance introgressed from Nicotiana africana to cultivated tobacco

Potato virus Y (PVY) is an important pathogen of to- bacco. Growing resistant cultivars is the best way to prevent si- gnificant losses of the crop caused by this virus. However, the protection given by the commonly used resistance factor, called va gene, can be overcome by the highly virulent PVY strains. Therefore, tobacco breeding for resistance will benefit from intro- ducing additional PVY resistance/tolerance factors. BPA is a to- bacco breeding line with introgressed PVY tolerance from a wild species N. africana. This trait is effective against a wide range of PVY isolates, including the ones that overcome va resistance. Here, we describe the inheritance of PVY tolerance of BPA. We obtained F1 and F2 plants from reciprocal crosses between BPA and a susceptible tobacco cultivar BP-210. Then we performed me- chanical inoculation tests using sap from PVY infected leaves on both generations of plants. Four weeks later we recorded disease symptoms and subjected all experimental plants to DAS-ELISA tests. All F1 plants developed vein necrosis which confirmed their susceptibility to the virus. The proportion of susceptible and tole- rant plants in the F2 fitted 3:1 ratio which was expected under the assumption that the tolerance is determined by a single, recessive gene. Moreover, the proportion of the susceptible and tolerant in- dividuals did not differ between two F2 populations derived from crosses where BPA was used as a maternal plant or a pollen do- nor, hence cytoplasmic factors do not influence the tolerance of that breeding line