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  • Brown rot blossom blight of pome and stone fruits: symptom, disease cycle, host resistance, and biological control
    15-21.
    Views:
    872

    In this paper, important features of symptoms, biology and biological disease management are summarised for brown rot blossom blight fungi of pome and stone fruit crops (Monilinia laxa, Monilinia fructicola and Monilinia mali). Firstly, European brown rot caused by Monilinia laxa is discussed highlighting the blossom epidemiology features, then host susceptibility of the most important stone fruit species including several Hungarian and international cultivars. At the end of this chapter, recent biological control possibilities against Monilinia laxa are also included. Secondly, American brown rot caused by Monilinia fructicola is discussed. Symptoms, biological features of blossom blight and host susceptibility of flowers to Monilinia fructicola are demonstrated. Finally, the symptoms and the biology of the least frequent species, Monilinia mali are shown.

  • Experimental results of the effects of Hungarian climatic conditions to German disease-resistant industrial apple varieties
    53-56.
    Views:
    122

    In the recent years, several disease-resistant apple varieties appeared through the modern breeding technologies. These varieties can be grown with low usage of pesticides, which mean not only environment friendly fruit growing, but the production costs are also lower. In Eastern-Hungary — it is one of the main apple growing regions — a new apple growing structure started to form by the investment of the German Wink Ltd. — several resistant apple varieties were brought from Germany. 'Resistant' refers genetic resistance that usually transferred from the genome of wild apple species. But the fruit of these apple species is not only resistant to diseases, but its quality is poorer, too. In Germany the Re-apples are grown only for the processing industry. Due to climatic circumstances in Eastern Hungary, the first experiences showed better parameters during laboratory measurement, the fruits have more beautiful view, shape and inner characters than usual industrial apples.

    In our paper we discuss the results of sensory (consumer) tests, carried out in Eastern Hungary and in the Budapest-region the data analysis of systematic storing experiments (refraction, flesh firmness, weight loss, etc.) and profile analysis of fresh and stored Re-apples. (In the profile analysis the ProfiSens software [4,5] has been used.)

  • High-velocity microprojectile mediated DNA delivery into Phaseolus vulgaris callus cells
    99-102.
    Views:
    123

    We report the method for the establishment of rapidly growing callus cultures of Phaseolus vulgaris and the conditions required for efficient transformation using high velocity microprojectiles and high level of transient gene expression. Using hypocotyl explant and vertical culture on B5 medium with lmg/1 kinetin and 2 mg/1 2,4-D, we can recommend to get a rapidly growing callus from bean which is a good starting material to introduce foreign DNA into bean cells. The GeneBooster particle delivery system was used for the bombardment of bean callus and the Hgm resistance gene (Hgmr) was used as a selectable marker gene. 25mg/I hygromycin (Hgm) concentration was sufficient to kill the control callus. We used the standard physical factors, the appropriate pressure of N2 gas for the bombardment of the callus tissue, the shooting distance and the size of tungsten particles used as microprojectiles. Selective and nonselective tests were made by transferring the healthy green and white calluses, subcultured for 4 months on selective and nonselective medium. Several Hgm resistant calli had been obtained. Selective pressure was maintained over a period of 10 months.

  • Ecological drought resistance and adaptability of apple varieties
    113-122.
    Views:
    404

    For adequate yields in apple plantations, during the long growing period of the fruit primordia, one of the decisive factors is water supply. Indicators of stress are valuable signs for the diagnosis of drought and necessity of watering, i.e. planning the irrigation of plantations. The aim of the present study was to find reliable signs of water stress on apple trees and at the same time conclude on the drought tolerance of different varieties. The plantation of apple varieties grafted on various stocks and cultivated according to different systems (irrigated, non irrigated, integrate and biological) has been examined continuously by leaf analysis. Along the period of growing fruits, measurements were made in the field, then the leaf samples were analysed in the laboratory for composition of pigments, carbohydrates and antioxidants, as well as the histology of the tissues checked. Without irrigation, the mean leaf mass and the relative chlorophyll content (SPAD) of the variety Idared on M4 stocks increases beyond the values of 50 SPAD, whereas on M26 stock and integrated system, it declines. In the collection of varieties, grown according to the „integrated” system, during the development of fruits, ‘Gála’ and ‘Remo’ varieties have been affiliated to the “less susceptible” group regarding drought tolerance because of the leaf morphology, structure and content of SPAD and antioxidants. However, ‘Idared’ and ‘Jonagold’ belong to the “susceptible” group. To the same group are ranged the ‘Akane, Red Rome vanWell, Pink Lady’ varieties. Those varieties reacted to a short period of drought by increased production (content) of carbohydrates. Regarding changes of carbohydrate content ‘Greensleeves’ and ‘Ozark Gold’ varieties belong to the moderately water dependent (requiring) group. In the field, SPAD-tests facilitated the measurement of nutrient-uptake and incorporation, which is proved by the tight correlation between the data of SPAD and the increment of leaf weight (r=0.76–r=0.88), however, this depends on the variety too. SPAD is an indicator of water supply and is related with the density of stomata, cannot used for the selection of water-exigent varieties but for (drought) tolerant ones. In integrated culture, the (drought) susceptible varieties display (water-soluble) hydrophilic and lipophilic antioxidants (ACWand ACL resp.) the quantity of which may have some role in drought tolerance.

  • Calla lily soft rot causal agents, symptoms, virulence and management: a review
    60-68.
    Views:
    152

    Bacterial soft rot is a polyetiological disease attacking calla lily [Zantedeschia spp (L.) Spreng.]. This disease has reduced the commercial value of this crop. This work aims to review scientific information to give an insight into calla lily soft rot causal agents, symptoms, factors favouring the disease, virulence mechanisms and management strategies. Special emphasis is put on the current progress with regards to understanding calla lily mechanisms of resistance to soft rot and their potential for the development of tolerant/resistant cultivars with commercial traits.

  • Blumeriella jaapii (Rehm) v. (Arx) infection of some sweet cherry cultivars in two years with different precipitation conditions
    37-39.
    Views:
    201

    We examined Blumeriella jaapii (Rehm) v. (Arx) infection on 21 sweet cherry cultivars in the cultivar-collection of the Experimental Station Pallag of the University of Debrecen, in 2004 and 2005. Considerable differences were detected in the infection degree of the different cultivars. In 2005, due to the more humid weather, the average infection highly exceeded data of the previous year. No symptomless cultivars were detected in either year. The least sensitive ones were Linda and the cultivar 11/106. The most sensitive cultivars were Early Müncheberg, Biggareau burlat and Round Solymári. Infection degrees of Alex, Rita and Vega were different from those of other cultivars on the basis of the two experimental years.

    It is important to consider both the specific weather conditions of the year and cultivar resistance at planning the plant protection system. It is recommended for each cultivar to perform a fungicide-spaying after the harvest.