EFFECT OF SOME BIOCIDES AND CHEMICALS ON TOMATO GENOME AND ITS RESISTANCE TO SOME PATHOGENS UNDER GREEN HOUSE AND TISSUE CULTURE TECHNIQUE

Abstract

Effect of Some Biocides and Chemicals on Tomato Genome and Its Resistance to Some Pathogens under Green House and Tissue Culture Technique. This study was applied in the Genetics department, Faculty of Agriculture, Ain Shams University during the period from 2011 to 2016.The experiment field was carried out in the laboratories of Central Lab of Organic Agriculture, Agricultural Research Center (ARC), Giza-Egypt. The practical experiments Effect of Some Biocides and Chemicals on Tomato Genome and their Resistance to Some Pathogens under Green House and Tissue Culture Technique distribution in the Plant Pathology Institute, Agricultural Research Center and the laboratory of department of Genetics, Faculty of Agriculture, Ain Shams University. Twelve tomato cultivars (Lycopersicon esculentum) were tested (Jaser, Super strain B, Castl rock, Nemathode, H3044, H9663, Hypeel H 513, Rimalady F1, Zmerald, Super star, Sara star H F1, Nada ) to Damping off diseases which caused by F. solani and R. solani, to get more of these cultivars resistant, moderatly susceptible and susceptible (three cultivar), and to assess its performance with biocides with active ingredient B. subtilis or T. harzianum and fungicides Rizolex or Topsen and identifying cytogenetic changes and their response in tissue culture experience. The results could be summarized as follows: 1-Fungal isolation and identification The strains were morphologically identified according to (Nelson 1926) and (Nelson et al 1983 and Brenneman 1997) purified by single spore transfer for F. solani and hyphal tip for R. solani by Hansen (1926) and identified by Barnett and Hunter (2003).

2- Antagonistic effect between B. subtilis and T. harzianum with two pathogenic fungi The results show that using of B. subtilis and T. harzianum resulted in significant reduction in mycelial growth of pathogenic fungus F. solani when treated with B. subtilis and T. harzianum were 25.176% -79.05% respectively compare with control treatment 0.00%. R. solani when treated with B. subtilis and T. harzianum were i were 26.82%-80.47% respectively compare with control treatment 0.00%. 3 - The interaction between the pathogens and antagonists This technique provides a clear view for the interaction between antagonists and pathogenic fungi through several tricks; 1- The hyphae of T. harzianum coiling around the mycelial of pathogenic fungi, mycoparasitism, penetrated hyphae of pathogens, lysis hyphae of pathogens, morphological changes in the hyphal growth of the pathogenic fungi such as; changes in colors to deep dark, also increased in the wide of the infected mycelium, swelling and Malformed mycelium. 4- Evaluation of different tomato cultivars against F. solani and R. solani Evaluation of 12 different tomato cultivars against F. solani revealed that all cultivars showed significantly increase in percentage of the pre- and post-emergence damping off under artificial infection with F. solani in greenhouse conditions when compared each cultivar to its control. And Severely reduced survival rate of (13.33%) than untreated control (66.66%) for Castle rock cultivar, Super strain B 60 % (control) and nemathoda 86.66 % (control). So the most sensitive cultivar was Castle rock, the most resistant cultivar was Nemathoda, and the tolerant cultivars were super strain B. while R. solani revealed that all cultivars showed significantly increase in percentage of the pre- and post-emergence damping off under artificial infection with R. solani in greenhouse conditions when compared each cultivar to its control. 5- Influence of biocide applied individually or in dual application and fungicide against F. solani and R. solani in for three tomato cultivars Different treatments of biocides and fungicides were used to determine the most effective one in controlling tomato damping off disease. Results revealed that all cultivars showed significant differences between treatments in pre-emergence damping off compared to control (4) spray with water and control (3) infested soil with F. solani. In Nemathoda cultivar which resistant to F. solani, the treatments increased the surviving plants to reach to control (4), except seeds treatments with B. subtilis and T. harizianum significantly reduced the pre- and post-emergence damping off. While R. solani treatment with fungicide Rizolex and Topsen, increased survival rate ranging between 96.66-90% respectively compared with the control (3), treatment of infected soil with B. subtilis 90% and T. harzianum 86.66%, when compared to control (3). For control F. solani and R. solani in Super strain B cultivar, all treatments show significant reduction for both pathogens compare with control treatment (3). No significant differences between effect of the using mixture of T. harzianum and B. subtilis were the lowest effective treatment. The most effective treatments were Topsen and Rizolex, no significant differences with control (3), and as the same for the Castle rock cultivar.