Seed treatment with aqueous extract ofViscumalbuminduces resistance to pearl millet downy mildew pathogen

Abstract

Downy mildew (Sclerospora graminicola [Sacc.] Schroet.) is a serious agricultural problem for pearl millet (Pennisetum glaucum [L.] R. Br.) grain production under field conditions. Six medicinally important plant species Azadirachta indica, Argemone mexicana, Commiphora caudata, Mentha piperita, Emblica officinalis and Viscum album were evaluated for their efficacy against pearl millet downy mildew. Seeds of pearl millet were treated with different concentrations of aqueous extract of the plants to examine their efficacy in controlling downy mildew. Among the plant extracts tested, V. album treatment was found to be more effective in enhancing seed quality parameters and also in inducing resistance against downy mildew disease. Germination and seedling vigor was improved in seeds treated with V. album extracts over control. Seeds treated with 10% concentration of V. album showed maximum protection against downy mildew disease under greenhouse and field conditions. The downy mildew disease protection varied from 44Á70% with different concentrations. Leaf extract of V. album did not inhibit sporulation and zoospore release from sporangia of Sclerospora graminicola, indicating that the diseasecontrolling effect was attributed to induced resistance. Seed treatment with V. album extract increased pearl millet grain yield considerably. In V. album, treated pearl millet seedlings increased activities of peroxidase, and phenylalanine ammonia-lyase enzyme was detected. FTIR analysis of V. album extracts showed the presence of amides and other aromatic compounds which are antimicrobial compounds involved in plant defense.

Induction of Resistance against Sorghum Downy Mildew by Seed Treatment with Duranta repens Extracts

“…The pearl millet seeds treated with aqueous plant extract of Viscum album had shown the maximum increase of the defence related enzyme like PAL [42]. In the present study, a significant increase of PAL in D. repens extract treated seedlings inoculated with pathogen was observed.…”

Priming of Plant Resistance to Heat Stress and Tomato Yellow Leaf Curl Thailand Virus With Plant-Derived Materials

“…For example, cinnamon oil, fennel oil, origanum oil, and thyme oil exhibit antifungal activities against Fusarium species (Park et al, 2017), whereas lemon oil can inhibit the growth of three phytopathogenic fungi ( Eutypa sp., Botryosphaeria dothidea , and Fomitiporia mediterranea ) that infect grapevine wood (Ammad et al, 2018). In addition to their direct antimicrobial effects, plant-derived materials have also been reported to synergistically and directly activate or prime treated plants to promote responses to biotic and abiotic stresses (Chandrashekhara et al, 2010; Ertani et al, 2013, 2014; Rouphael et al, 2017). The essential oil from Gaultheria procumbens induces SA-mediated defense responses and resistance to Colletotrichum higginsianum in A. thaliana (Vergnes et al, 2014).…”

Effect of some plant extracts on Meloidogyne arenaria Neal, 1889 (Tylenchida: Meloidogynidae) and tomato

“…Reports about induced resistance with used extracts of V. album against plant bacterial diseases have been reviewed by Zeller (2006). Chandrashekhara et al (2010) tested that seeds of pearl millet were treated with different concentrations of aqueous extract of the plants to examine their efficacy in controlling downy mildew (Sclerospora graminicola [Sacc.] Schroet.).…”