The Effect of Fungi Accompanying cuscuta on the Germination Rates of Ocimum and cuscuta Seeds and Their Molecular Diagnosis

Abstract

This study was conducted at the Faculty of Agricultural Engineering Sciences / Plant Protection Department / University of Baghdad-Jadriya, with the aim of isolating fungal pathogens from samples of the parasite on different plant families (Solanum, Astragalus, Conocarpus, chenopodium, Alhagi, Ocimum) from several areas in Baghdad and Diyala Governorate and diagnosing them phenotypically and testing their pathogenicity. The results of isolation and phenotypic diagnostics from the stems and seeds of the cuscuta showed the presence of 12 genera belonging to nine species : Alternaria, sp. (F2), Alternaria sp. (F4), Aspergillus sp. (F6), Aspergillus sp. (F12), Chaetomium sp. (Amesia sp.) (F7), Cladosporium sp. (F8), Curvularia sp. (F5), Helminthosporium sp. (F10), Penicillium sp. (F9), Rhizoctonia solani (F1), Stemphylium sp. (F3), Stemphylium sp. (F11). The results showed that the fungus Aspergillus sp., Curvularia sp., Chaetomium sp. Helminthosporium sp. and SP. Stemphylium was first recorded on the Cuscuta plant in Iraq. The results of the pathogenetic assessment showed that all the tested isolates (F1-F12) were pathogenic to Porter and Ocimum seeds, as they caused a significant reduction in seed germination rates compared to the control treatment (without inoculation with fungal vaccine). it was found that there was a difference between fungal isolates in reducing the percentage of seed germination, as some fungal isolates achieved the highest reduction in the percentage of germination of carrier seeds. the effect of their fungal filters on the germination of Porter and Ocimum seeds was tested and diagnosed in part. The results showed that the leached fungus Chaetomium sp. With concentrations of 20, 40 and 60%, it significantly reduced the percentage of germination of Porter seeds and differed significantly with the coefficients of Aspergillus SP.(F6) fungal filters, Stemphylium sp.(F3), Alternaria sp.(F4), Curvularia sp.(F5) by analogy with the comparison treatment, while there are no significant differences between the fungal filtrate at the three concentrations. The results also showed that the fungus leached Chaetomium sp.(F7). And Aspergillus sp. sp.(F6) in concentration, it had a significant effect in reducing the percentage of germination of Ocimum seeds compared to the comparative treatment. She showed that the isolates belong to fungi (F2 Aspergillus Flavus and(F4) Alternaria alstroemeria and that F5 Curvularia spicifera and F3 Stemphylium vesicarium and F7 belong to Amesia atrobrunneum and the name was changed instead of the old name Chaetomium atrobrunneum and deposited in the gene bank Gene Bank and NCBI under the accession numbers oq746923, Oq746924, Oq746925 and Oq74692.