Novi podaci o nazočnosti biljnih virusa u rijekama i jezerima Mađarske

In two year experiments a survey was carried out on the presence of plant viruses in Hungarian rivers and lakes. Water samples from 14 rivers and three lakes were collected and after concentrating by ultracentrifugation they were tested by ELISA method for the presence of 26 plant viruses. The results of the serological tests were confirmed by biological assay on herbaceous test plants. According to the results, out of 47 investigated water samples 17 proved to contain infectious plant viruses belonging to caria- (PVM, PVS), cucunio- (CMV), monogemini- (WDV), necro- (TNV), nepo- (ArMV), poly- (PPV, ZYMV), tobra- (TRV) and tospovinis (TSWV). CMV, PVM and PPV were found more often. ArMV, PVM, TSWV, WDV and ZYMV were found for the first time in natural waters.Tijekom dviju godina istraživana je nazočnost biljnih virusa u površinskim vodama Mađarske, u 14 rijeka i tri jezera. Sadržaj 47 prikupljenih uzoraka vode, svaki volumena 500 mL, bio je najprije koncentriran visokookretajnim centrifugiranjem. Nastali taloži bili su zatim otopljeni zasebno u dva odgovarajuća pufera i istraženi osjetljivom serološkom metodom ELISA pomoću antiseruma od 26 virusa i na osnovi reakcije pokusnih biljaka nakon njihove mehaničke inokulacije. Nazočnost infekcioznih virusa dokazana je u 17 uzoraka vode, i to ukupno njih 10: M virus krumpira (PVM), S virus krumpira (PVS) (rod: Carlavirus), virus mozaika krastavca (CMV) (rod: Cucumovirus), virus kržljavosti pšenice (WDV) (rod: Monogeminivirus), virus nekroze duhana (TNV) (rod. Necrovirus), virus mozaika gušarke (ArMV) (rod: Nepovirus), virus šarke šljive (PPV) i virus žutog mozaika tikvice (ZYMV) (rod: Potyvirus), virus šuštavosti duhana (TRV) (rod: Tobravirus) i virus pje- gavosti i mozaika rajčice (TSWV) (rod: Tospovirus). Nađena su i daljna dva virusna izolata koja zasad još nisu identificirana. Nešto češće od drugih virusa bili su nađeni CMV, PVM i PPV. Od naprijed navedenih virusa po prvi puta uopće otkriveni su u prirodi kao kontaminantni u vodama ArMV, PVM, TSWV, WDV i ZYMV. U radu se daje pregled dosadašnjih nalaza biljnih virusa u površinskim vodama (uglavnom vodotoci i jezera) zemalja svijeta

Results of the study of cross-resistance and effect of herbicide on crops in the production of cycloxydim-tolerant maize (Zea mays L)

In Hungary, monocot weed species are present as a signiἀcant yield limiting factor. In practice there is a great demand for efἀciently applying agrochemicals against monocot weeds at a later period and without causing phy totoxicity. Field trials were carried out in 2010 and 2011. The trials aimed to understand whether the cycloxydim-tolerant (CT) maize have cross-resistance to herbicides expressing different graminicide action (quizalofop-p-tefuril, haloxyfop-r-methyl ester, propaquizalofop, Ḁuazifop-p-butyl). The obtained results conἀrm that CT maize has signiἀcant tolerance to cycloxydim active substance. Lower rates of other types of graminicides neither damage maize plants nor reduce the yield, while application of higher rates used to control perennial weeds do. According to the authors’ conclusions, no other types of graminicides can be used to perform chemical weed control in CT maize. Post-emergent use of cycloxydim showed excellent efἀcacy against monocot weeds: Echinochloa crusgalli, Setaria verticillata, Panicum miliaceum. It is well-known that growing genetically modiἀed maize is greatly restricted in Europe, therefore the published scientiἀc results provide good option for the control of monocot weeds in the maize growing areas

Invázív gyomnövények biológiája, ökológiája és vírusepidemiológiai jelentősége = Biology and ecology of invading weeds and their virus epidemiological role

2005 és 2010 között a hazai fontosabb inváziós "özöngyomok" (Asclepias syriaca, Ambrosia artemisiifolia, Abutilon theophrasti, Solidago gigantea, Cyperus esculentus, Phytolacca americana) természetes vírusfertőzöttségét mértük fel, továbbá több új mesterséges gazda-vírus kapcsolat feltárására is sor került. Laboratóriumi és üvegházi csírázásbiológiai vizsgálatokban meghatároztuk a fajok magjainak csírázóképességét, valamint a csírázást befolyásoló autökológiai tényezőket, és nyomon követük a magvak életképességének változását. Kompetíciós kísérletekben meghatároztuk a kukorica kritikus kompetíciós periódusát, valamint a helyettesítési és az additív módszerek alkalmazásával összehasonlítottuk a gyomfajok versenyképességét. A növekedésanalízis segítségével, továbbá a biomassza- és magprodukciós vizsgálatokban meghatároztuk a fajok tényleges biológiai potenciálját. Üvegházi tenyészedényes allelopátiás kísérletekben a fajok közötti kémiai kölcsönhatásokat tanulmányoztuk, ahol a tesztfajok donor és recipiens szerepet is betöltöttek. Az aktuális és a szubletális víztelítettségi deficit meghatározásával a fajok vízháztartási sajátosságait jellemeztük. | Between 2005 and 2010 years the natural and artificial virus infection of the most important invasive alien weed species (Asclepias syriaca, Ambrosia artemisiifolia, Abutilon theophrasti, Solidago gigantea, Cyperus esculentus, Phytolacca americana) was studied in Hungary. A lot of new host-virus relations were determined. The change in the germination percent, seed viability and autecological factors influencing germination characteristics were also investigated. Critical competition period of maize was determined and the competitive ability of the weed species was compared based on the results on additive and replacement glasshouse and field studies. Effective biological potential of the invasive alien plant species was also determined with the help of growth analysis and in biomass and seed production experiments. Under glasshouse conditions the donor and recipient role of the weeds was also studied in allelopathic research. Water relations of the species were characterized with the actual and sublethal water saturation deficits