Influence of Bacillus Spp. Based Bioproducts on Potato Plant Growth and Control of Rhizoctonia Solani

Some Bacillus based bioproducts were analyzed for their plant growth promotion and Rhizoctonia solani biocontrol potential in potato plants. The bioproducts were formulated as concentrated aqueous suspension, each containing one of the following plant beneficial bacteria: Bacillus safensis Rd.b2, Bacillus spp. 75.1s and Cp.b4 strains. These were applied on potato seeding material in order to evaluate plant growth promotion effects. The biocontrol efficacy was also evaluated, using Rhizoctonia solani DSM 63002 as plant pathogen, and Prestige 290FS as reference chemical treatment.In the plant growth-promotion experiments, several biologic parameters were biometrically evaluated. Best results regarding plant growth and vigor were obtained using CropMax, a commercial phytostimulatory product. However, the bacterial treatment with Bacillus spp. Cp.b4 and 75.1s showed an improved plant growth compared to the untreated control. An efficacy of 93.75% against Rhizoctonia dumping-off was registered when using the Prestige 290FS chemical control. Mix treatments based on this pesticide, in low dose, combined with Cp.b4 or 75.1s biocontrol strains significantly reduced the pathogenic attack, showing 85 to 87.5% efficacy.The present research demonstrated that the bacterial bioproducts based on Bacillus spp. 75.1s and Cp.b4 strains increase plant growth and are highly effective in controlling Rhizoctonia attack in potato plants

In vitro effect of salinity and pH on Fusarium sp., the causal agent of sweet-potato root rot

Fusarium root rot in a common pathogen of sweet potato, with a wide range of host plants. In the current study six new isolates of Fusarium sp., collected from infected sweet potato plants, along with a reference strain of Fusarium oxysporum, had their growth behavior studied in various pH and saline conditions. In vitro studies showed that salinity higher than 6% NaCl in the PDA substrate significantly reduces the fungal growth. At 12% NaCl, four of seven strains revealed complete mycelia inhibition. However, for the other two isolates, and for the reference strain, 12% salinity only reduced the growth with 77.4%. Regarding the fungal growth at different pH values, it was noticed that tested fusaria were not perturbed at up to 8.5 alkalinity. However, at a pH of 4.5, the growth rate was reduced, although the growth differences were diminished during prolonged incubation time. Considering the in vitro results, saline water should be tested as preventive immersion treatment on the sweet potato sprouts, before their planting, in order to reduce the incidence of Fusarium infection

MICROBIAL INOCULANTS APPLIED AS SEED TREATMENTS AND THEIR EFFECT ON COMMON WHEAT Triticum aestivum L.

Wheat is considered the most wide spread culture in the world regarding the area harvested. In Romania, it is grown on approximately 25% of the arable land and 40% of the cereal grains. Improving wheat productivity and yield quality is a continuous concern. Therefore, plant growth promoting microorganisms with biocontrol potential are of great interest for the farmers. In the present, five beneficial microorganisms, bacteria and fungi, were analysed as agro-inoculants. Their effect on wheat germination and growth initiation was evaluated in vitro. According to the biometric analysis best results were obtained when using Azospirillum brassilense and Bacillus amyloliquefaciens strains, although Trichoderma pseudokoningii and Bacillus endophyticus also improved wheat vigour indexes, compared to the untreated control. However, B. endophyticus 1T2 strain delayed the germination process. The dual culture assay performed against Fusarium graminearum, revealed that three strains B.amyloliquefaciens OS17, BW, and T.pseudokoningii Td85, have also biocontrol potential

Microorganisme benefice plantelor cu efect de solubilizare a siliciului

Silicon is the second abundant element on Earth. Commonly, it is found as silica and silicates, or in biology as mineral constituent of microorganisms, protozoa and plants. Although silicon it is not considered an essential nutrient for plants, it has been noticed that available silicon positively influences plants’ growth, mechanical strength, and resistance to several biotic and abiotic unfavorable conditions, such as fungal phytopathogens, herbivores and adverse chemicals. Our study presents several microbial strains able to solubilize silicon from different biological and mineral substrates. Some of these microorganisms were isolated from plant material with high content of mineral silicon like horsetail, wheat straw, rosemary and nettle. Moreover, microbial supernatant obtainedon horsetail broth increased hypocotyl and roots length of cowpea Vignaunguiculata (L.) Walp

FIG. 5 in Biological activity of some Romanian and Turkish Trichoderma Pers. strains

FIG. 5. — Metabolic activity in biofilm and antibiofilm effect of Trichoderma spp. against human pathogenic bacterial strains. Symbols: ns, no significant; *, p <0.05; **, p <0.01; ***, p <0.001; ****, p <0.0001.Published as part of <i>Tunç, Gülhan, Boiu-Sicuia, Oana-Alina, Şahiner, Aslı, Kuzucu, Volkan, Dogan, Nazime Mercan & Langerholc, Tomaž, 2023, Biological activity of some Romanian and Turkish Trichoderma Pers. strains, pp. 135-145 in Cryptogamie, Mycologie 20 (10)</i> on page 142, DOI: 10.5252/cryptogamie-mycologie2023v44a10, <a href="http://zenodo.org/record/10144278">http://zenodo.org/record/10144278</a&gt

FIG. 3 in Biological activity of some Romanian and Turkish Trichoderma Pers. strains

FIG. 3. — Mycoparasitic activity of Trichoderma Td-Exp1 strains against plant pathogens:A, Botrytis cinerea Pers.; B, Fusarium graminearum Schwabe;C, Sclerotinia sclerotiorum (Lib.) de Bary. Scale bars: 1 cm.Published as part of <i>Tunç, Gülhan, Boiu-Sicuia, Oana-Alina, Şahiner, Aslı, Kuzucu, Volkan, Dogan, Nazime Mercan & Langerholc, Tomaž, 2023, Biological activity of some Romanian and Turkish Trichoderma Pers. strains, pp. 135-145 in Cryptogamie, Mycologie 20 (10)</i> on page 141, DOI: 10.5252/cryptogamie-mycologie2023v44a10, <a href="http://zenodo.org/record/10144278">http://zenodo.org/record/10144278</a&gt