Authors:S. Bencze, G. Vida, K. Balla, E. Varga-László and O. Veisz
Infection with fungal pathogens on wheat varieties with different levels of resistance was tested at ambient (NC, 390 ppm) and elevated (EC, 750 ppm) atmospheric CO2 levels in the phytotron. EC was found to affect many aspects of the plant-pathogen interaction. Infection with most fungal diseases was usually found to be promoted by elevated CO2 level in susceptible varieties. Powdery mildew, leaf rust and stem rust produced more severe symptoms on plants of susceptible varieties, while resistant varieties were not infected even at EC. The penetration of Fusarium head blight (FHB) into the spike was delayed by EC in Mv Mambo, while it was unaffected in Mv Regiment and stimulated in Mv Emma. EC increased the propagation of FHB in Mv Mambo and Mv Emma. Enhanced resistance to the spread of Fusarium within the plant was only found in Mv Regiment, which has good resistance to penetration but poor resistance to the spread of FHB at NC. FHB infection was more severe at EC in two varieties, while the plants of Mv Regiment, which has the best field resistance at NC, did not exhibit a higher infection level at EC.The above results suggest that breeding for new resistant varieties will remain a useful means of preventing more severe infection in a future with higher atmospheric CO2 levels.
Authors:R. Bán, G. Fischl, A. I. Engloner and F. Virányi
Fischl, G., Bürgés, Gy. and Szeglet, P. (1998): Plant hygiene conditions of the reed in Lake Balaton with special view of fungaldiseases. Proceedings 50th Int. Symp. of Crop Protection. Gent. III. pp. 869-871.
Studies on the ecological behaviour of Cochliobolus miyabeanus (Ito et Kurib.) Drechsl. ex Dast., syn. Bipolaris oryzae (Breda de Haan Shoem.), the causal agent of brown spot in rice (Oryza sativa L.), were carried out in the tidal mangrove swamp at Warri Experimental Farm, Southeastern Nigeria. A split randomised complete block design with four replications was used. Monthly transplantings from July to September formed the main plot, which was subdivided into control and N-treated subplots. Disease incidence increased when transplanting was delayed. This was probably due to the fact that flowering coincided with environmental conditions favourable for disease development from November to February. Nitrogen fertilization at 40 kg N/ha significantly (P=0.05) reduced C. miyabeanus incidence in 1997/1998, but not in the 1998/1999 and 1999/2000 cropping seasons at the same site. The grain yields of ROK 5, a medium-duration improved rice variety (approx. 150 days), were significantly (P=0.05) reduced in late-transplanted crops (September to November) in spite of adequate N fertilization. Mangrove mud was not an important source of C. miyabeanus propagules. The incidence of leaf scald caused by Monographella albescens (Thum) Parkinson, Sivanesan and Booth syn. Microdochium oryzae (Hashioka and Yokogi) Samuels and Hallet, and of leaf smut caused by Etyloma oryzae Miyake was generally stimulated by N application.
Authors:G. Vida, M. Cséplő, G. Gulyás, I. Karsai, T. Kiss, J. Komáromi, E. László, K. Puskás, Z. Wang, C. Pace, Z. Bedő, L. Láng and O. Veisz
Among the factors which determine yield reliability an important role is played by disease resistance. One of the breeding aims in the Martonvásár institute is to develop wheat varieties with resistance to major diseases. The winter wheat varieties bred in Martonvásár are examined in artificially inoculated nurseries and greenhouses for resistance to economically important pathogens. The effectiveness of designated genes for resistance to powdery mildew and leaf rust has been monitored over a period of several decades. None of the designated major resistance genes examined in greenhouse tests is able to provide complete resistance to powdery mildew; however, a number of leaf rust resistance genes provide full protection against pathogen attack (Lr9, Lr19, Lr24, Lr25, Lr28 and Lr35). In the course of marker-assisted selection, efficient resistance genes (Lr9, Lr24, Lr25 and Lr29) have been incorporated into Martonvásár wheat varieties. The presence of Lr1, Lr10, Lr26, Lr34 and Lr37 in the Martonvásár gene pool was identified using molecular markers. New sources carrying alien genetic material have been tested for powdery mildew and leaf rust resistance. Valuable Fusarium head blight resistance sources have been identified in populations of old Hungarian wheat varieties. Species causing leaf spots (Pyrenophora tritici-repentis, Septoria tritici and Stagonospora nodorum) have gradually become more frequent over the last two decades. Tests on the resistance of the host plant were begun in Martonvásár four years ago and regular greenhouse tests on seedlings have also been initiated.
Authors:M. I. Kiseleva, A. V. Ovsyankina, T. M. Kolomiets, N. S. Zhemchuzhina and A. P. Glinushkin
Since 1995 the pathogens of genus Fusarium causing Root Rot, Snow Mold, Fusarium Head Blight of grain crops have been monitored in the Volga-Vyatka, Central, Central Chernozem and North Caucasian regions of the Russian Federation and in there were identified 15 Fusarium spp.: F. culmorum, F. heterosporum, F. sporotrichioides, F. oxysporum, F. nivale, F. graminearum, F. avenacеum, F. gibbosum, F. sambucinum, F. moniliforme, F. semitectum, F. poae, F. lateritium, F. solani, F. redolens. The high uniformity of Fusarium spp. has been revealed for the regions due to the susceptibility of crops to the soil-inhabiting micromycetes. Consistent long-term monitoring of the dynamics and frequency of occurrence of Fusarium spp. in a wide range of climatic areas has made it possible to characterize the state of the species of fungi in the regions and also to study their intraspecific and interspecific variability in toxicity and pathogenicity depended on biotic and abiotic factors. The prevalence of Fusarium spp. in the mycobiota has been determined by their plasticity and viability in the soil, on the weed roots and in the stubble of many crops and high competitive ability expressed pathogenicity and toxicity.
Timopheevii wheats are discussed as donors for improving the disease resistance of common wheat. Attention is paid to the comparison of the morphological and chromosomal characteristics of Triticum timopheevii and T. militinae, their crossability with T. aestivum and their response to fungal diseases. The possible origin of T. militinae from an introgressive hybridization between T. timopheevii and an unknown species is discussed. Major genes for resistance to various fungal diseases, transferred to common wheat from T. timopheevii, are listed.
Authors:E Burgettiné Böszörményi, S Németh, A Fodor, K Bélafiné Bakó, D Vozik, Z Csima and I Barcs
C. albicans is part of the normal human microflora, but under certain circumstances, it may cause superficial or invasive fungaldiseases. It may produce a biofilm on a biotic or abiotic surface and its adhesion is supported by adhesins [ 2 ]. Its
Blossom blight caused by
(Ehr.) is the most important fungal disease in Hungarian apricot orchards. The cultivars traditionally grown in the country are susceptible to
(Ehr.) to various extents. In this study the shoots of one tree each of the varieties Zard and Korai Zamatos and 48 hybrids from their cross were artificially infected
(Ehr.). The results indicated that when artificial infections are made to evaluate pathogen resistance, this should be carried out on one-year-old shoots, since this is the natural infection point of
. It also appears that, due to the great variability in the size of destroyed tissues, the microscopic analysis of the infections could provide a more reliable evaluation of progeny resistance than comparing the sizes of destroyed shoot areas.
L.) is one of the most economically important crops around the world. Diseases caused by fungi and viruses significantly reduce yield. The most important fungal diseases are leaf rust caused by
, and powdery mildew caused by
. The most economical and ecologically friendly way to avoid losses caused by these diseases is growing resistant varieties. Concerning practical breeding for powdery mildew and leaf rust resistance, simple, cheap and robust selection methods are required. Marker assisted selection (MAS) is of great potential to fulfil this demand. In this paper, we present development of a robust duplex marker for simultaneous selection of
, and presence of one of the following
Mla16, Mla19, Mla20, Mla21, Mla27