Evaluation of alkaloid profiles in hybrid generations of different poppy (Papaver somniferum L.) genotypes

Five varieties (‘Minoan’, ‘Medea’, ‘Korona’, ‘Przemko’, ‘Kozmosz’) of poppy representing different chemotypes were combined and the alkaloid profiles of F1-F3 progenies were studied during 2006-2009.In the crosses of high alkaloid containing varieties the content of total alkaloids and that of morphine and thebaine showed increased levels in the hybrid generations which persisted till F3. Narcotine (noscapine), however accumulated at lower level than the midparent values and showed a decreasing tendency over generations. A higher number of homogenous strains starts to appear in F3 progenies. The majority of codeine containing individuals concentrates to certain strains. A growing number of high thebaine containing individuals was observed in several combinations. In the crosses with low alkaloid containing parent (‘Przemko’) the F1 exhibits considerable heterosis for total alkaloid content. Low alkaloid containing recessive individuals segregate in F2 and stabilise in F3.Results of our crossing experiments reflected well the effects of genetic regulation at three levels of enzymatic processes during the biosynthesis of poppy alkaloids. Data support the recessive determination of transformations at TyDC (tyrosine decarboxylase) and BBE (berberine bridge enzyme) levels while more complex (polygenic) effects are supposed in controlling the quantity of narcotine (noscapine) and morphinanes. Selection for fixing very low alkaloid content and narcotine may be effective in early F2 generations, however a selection for morphinanes is not worthy before F3.     

Incidence of grapevine trunk diseases is influenced by soil,topology and vineyard age,but not by <Emphasis Type="Italic">Diplodia seriata</Emphasis> infection rate in the Tokaj Wine Region,Hungary

Grapevine Trunk Diseases (GTD) are of great importance worldwide, including Hungary, a Center European country with long wine producing history. Several GTD pathogens have been described till now in Europe, but only a few from Hungary. The presence of a GTD pathogen in the vine does not necessarily result in the immediate appearance of disease symptoms, and information on the importance of environmental factors related to disease incidence are still limited. The aim of this research was to assess the occurrence of GTD in the Tokaj Wine Region, and to determine the biotic and abiotic factors influencing disease incidence. Five vineyards within 15 km radius – each with different topology, soil types, varieties and age – were studied for three consecutive years (2013 – 2015). The incidence of GTD-infection was determined every year for each vineyard. Diplodia seriata was isolated with incidence ranging from 50 to 100%, while Diaporthe spp. were the only other – minor – GTD pathogen found. Topology and soil type appeared to be major abiotic factors affecting incidence of GTD symptom. Disease incidence was also positively correlating with the age of the vineyards, and it was in fact found to be the definitive biotic factor regarding incidence. In contrast, D. seriata infection rate appeared unrelated to disease incidence or to any of the biotic or abiotic factors investigated.     

Protective role of <Emphasis Type="Italic">S</Emphasis>-methylmethionine-salicylate in maize plants infected with <Emphasis Type="Italic">Maize dwarf mosaic virus</Emphasis>

This study aimed to detect the harmful effects of Maize dwarf mosaic virus (MDMV) infection, and to demonstrate the potential benefits of S-methylmethionine-salicylate (MMS) pretreatment in infected maize (Zea mays L.) plants. The results of chlorophyll a fluorescence measurements showed that in MDMV-infected plants additional quenchers of fluorescence appear, probably as the result of associations between the virus coat protein and thylakoid membranes. It is important to note that when infected plants were pretreated with MMS, such associations were not formed. MDMV infection and MMS pretreatment resulted in a decrease in ascorbate peroxidase (APX) activity in maize leaves, while infection contributed to an increase in activity in the roots. Infection raised the guaiacol peroxidase (GPX) enzyme activity level, which was reduced by MMS pretreatment. MMS contributed to a decrease in both the RNA and coat protein content of MDMV, to an equal extent in maize leaves and roots. The results showed that MMS pretreatment enhanced the stress response reactions against MDMV infection in maize plants and retarded the spreading of infection.