Identification and in vitro control of the causal agent of wilt in onion

Onion seedlings with wilt symptoms were collected from the state of guerrero,mexico,from which fusarium oxysporum f. sp. cepae was isolated and identified,based on the colony and conidia structure´s morphological characteristics. a pathogenicity test was conducted,inoculating healthy onion seedlings with the isolated pathogen,while the control seedlings were sprayed with sterile distilled water only. control seedlings remained healthy while inoculated ones developed wilt symptoms seven days after inoculation,similar to those observed in the production area. f. oxysporum f. sp. cepae was re-isolated and the genomic dna extraction,pcr,and sequencing test were carried out. based on morphological identification and pathogenicity tests,it was determined that f. oxysporum f. sp. cepae was the causal agent of wilt in onion,although the molecular identification was only carried out on a genus level. additionally,different biocontrol products were evaluated in vitro including fungicides and phyto-extracts in order to determine the inhibition of the pathogen. the products used were as follows: trichoderma asperellum strain obtained at csaegro (100%),t. harzianum (100%),prozycar (100%),cupravit (100%) manzate (100%),busan (100%),q-2000 (60%),neem extract (51%) and garlic extract (27%). © 2017,university of agriculture. all rights reserved.