Soğanda tohumla taşınan bazı önemli fungal hastalıklar ve arpacığa geçiş durumları

Abstract

ÖZET Türkiye'nin değişik illerinden 18 tohum örneği getirtilmiş ve örneklerin her birinden tohum kabuğu, embriyo ve endosperm kısımları kültüre alınarak incelenmiştir. Bu inceleme sonucunda belirlenen fungal etmenlerin arpacığa geçişini tespit etmek amacıyla tohum örnekleri steril toprakta ve tarla koşullarında geliştirilmiştir. Aspergillus alutaceus Berk and Curt., Beauveria bassiana (Bals.) Vuill. Cladosporiumcladosporioid.es (Fresen.) de Vries, Geotrichum sp., Humicola Juscoatra Traaen, Trichoderma harzianum Rifai, Trichoderma pseudokoningii Rifai, soğan tohumu kısımlarında, Fusarium culmorum (W. G. Sm.) Sacc.,Fusarium sambucinum Fuckel, Fusarium graminearum Schwabe arpacığın kök ve yumrularında ilk kez bu çalışma ile tespit edilmiştir. Aspergillus niger van Tieghem soğan tohumunda özellikle tohum kabuğunda, steril toprakta ve tarla koşullarında geliştirilen arpacıkların kök ve yumrularında en yüksek oranda tespit edilmiştir. Aspergillus niger van Tieghem 'den sonra, Fusarium oxy sporum Schlecht. steril toprakta geliştirilen arpacıklarda en yüksek oranda belirlenmiştir. Fusarium acuminatum (Ellis) Everh. Fusarium sambucinum Fuckel, Fusarium equiseti (Çorda) Sacc. sadece steril toprakta geliştirilen arpacıklarda tespit edilmiştir. Aspergillus niger van Tieghem ve Fusarium oxy sporum Schlecht. 'un tohumdan arpacığa geçiş yapabildiği, bununla birlikte tespit edilen diğer türlerin sadece tohum kısımlarında bulaşık olduğu tespit edilmiştir. ANAHTAR KELİMELER: Soğan, soğan tohumu ve arpacık, fungus, taşınma.

II SUMMARY In this study, 18 seed samples were collected from the various proviences of Turkey. Onion seeds were examined internally, for this aim they were cultured as seed coat, embriyo and endosperm, and the transmission of the determined fungi to onion sets were investigated both in sterile and field soil. Among the determined fungi, Aspergillus aluteceaus Berk and Curt., Beauveria bassiana (Bals.) Vuill., Cladosporium cladosporioid.es (Fresen.) de Vries, Geotrichum sp., Humicola fuscoatra Traaen, Trichoderma harzianum Rifai, T. pseudokoningii Rifai in onion seeds; Fusarium culmorum (W. G. Sm.) Sacc, Fusarium sambucinum Fuckel, Fusarium gramlnearum Schwabe in onion sets were recorded at the first time. Aspergillus niger van Tieghem was found at the highest rate in seed samples (especially in seed coat), in bulb and roots of onion sets developed from these seeds that grown in sterile and field soil. Fusarium oxysporum Schlecht. was isolated at higher rate from onion sets which were grown in sterile and field soil than the seeds. F. acuminatum (Ellis) Everh., F. sambucinum Fuckel, F. equiseti (Corda) Sacc, F. graminearum Schwabe were only isolated from onion sets developed in sterile soil. In dual culture tests, these Fusarium isolates belonging to Fusarium species were inhibited by Aspergillus niger van Tieghem for this reason, they could not developed in agar plate except for F. oxysporum Schlecht. could appeared in onion sets grown in sterile soil and they were inhibited by other fungi in field soil. It was concluded that all isolated fungi were seed-borne, but Aspergillus niger van Tieghem and Fusarium oxysporum Schlecht. were transmitted from the seeds to onion sets, but other fungi were not. KEY VORDS: Onion, onion seeds and sets, fungi, transmission