Health quality and reduction of pathogenic transmission in tomato seeds using plant extracts

Abstract

The objective of the present study was to assess the seed health quality, quantification of seed-seedling pathogen transmission and the effect of plant extracts in reducing plant pathogens in the seeds of the tomato varieties San Marzano and Ipa 6. For the seed health, the samples were disinfested, plated and assessed after seven days, according to the Brazilian Seed Analysis Rule. For the transmission rate, 12 trays were prepared with 100 seeds each and assessed at 7, 14 and 21 d.a.s. (days after seeding) using 100 seedlings. The plant (main root, stalk and leaves) tissues were plated in PDA culture medium and assessed after seven days of incubation. Aqueous extracts were prepared from cinnamon, basil, neem and eucalyptus with 0.5% concentration and the seeds were immersed in each solution for 10 minutes. Then, they plated and assessed after seven days. The health test showed that biggest incidences of Aspergillus fumigatus (26 %) and Aspergillus flavus (26 %) were occurred in the seeds of the varieties Ipa 6 and San Marzano, respectively. The fungi A. flavus, A. fumigatus, A. niger, R. stolonifer and Curvularia sp. were detected in quantification of transmission in the seeds of the two tomato varieties. The treatment with basil extract resulted in the least fungus incidence in the transmission quantification of ‘San Marzano’ tomato seeds, while on Ipa 6 seeds the eucalyptus treatment performed better. The interference of treatments was not observed in tomato seed germination. However, there was decrease in incident of pathogens in seeds treated with the plant extracts and different effects was observed based on type and species of the pathogen.

Antibacterial Activity of Essential Oils and Trametes versicolor Extract against Clavibacter michiganensis subsp. michiganensis and Ralstonia solanacearum for Seed Treatment and Development of a Rapid In Vivo Assay

“…Overall, no particular phytotoxic effects have been recorded in the literature for the six EOs tested on tomato seeds. For example, in one study, different essential oils (among them thyme, basil, and clove bud) were applied to tomato seeds without affecting their germination [45], and the same was observed for oregano [52,53], garlic [54], and cinnamon [55]. Tve did not show any phytotoxic effects on maize seeds [56] or wheat plants, resulting from its use as plant growth promoter and elicitor of plant defense [49].…”

“…tomato (Pst), reducing the seed-borne bacterial speck disease of tomato [53]. Concerning cinnamon oil, Dos Santos e Silva [55] reported a decrease in incidence of fungal pathogens associated with tomato seeds after treatment, but, in general, less information about the cinnamon seed treatment against bacteria in tomato are available.…”