2022-11-23
Ashiya Akter Sumi, Abul Khayer, Pijush Kanti Jhan, Mehede Hassan Rubel
Black rot in cabbage caused by Xanthomonas campestris pv. campestris is the most common yield-limiting and damaging disease affecting crucifers. The application of chemicals has hazardous effects on the soil and environment. To test bio-based alternatives for chemicals, extracts of 10 medicinal plants (royal poinciana, ivy gourd, sisso, bougainvillea, mint, devil’s cotton, drumstick, false daisy, asthma plant, and mimosa) were tested for their antibacterial effects against Xanthomonas campestris pv. campestris . The extracts were prepared in distilled water and ethanol at two concentrations, 25% and 50%. The extracts were applied, and a standard antibiotic disk (streptomycin 10 µg/disc) was used to evaluate the antibacterial activities. In the present study, antibacterial screening using the disk diffusion method revealed that both the aqueous and ethanol extracts of seven plant samples: royal poinciana, ivy gourd, sisso, bougainvillea, mint, devil cotton, and drumstick, showed significant activity, while extracts (aqueous and ethanol) of false daisy, asthma plant, and mimosa showed weak inhibitory effects against the tested bacteria. For both aqueous and ethanol extracts, antibacterial effects were higher at 50% concentration.
2022-10-04
Adelina Harizanova, Lyubka Koleva-Valkova, Andon Vassilev
This study aimed to evaluate the effects of the protein hydrolysate Naturamin WSP on the antioxidant defense system and oxidation-related damage of young cucumber plants exposed to chilling stress. Low positive temperatures have a negative effect on plant growth and performance, and besides visible alterations, such as inhibited growth, significant changes occur at the cellular level. Plants grown at low temperature typically suffer from oxidative damage, which leads to increased lipid peroxidation. Moreover, chilling-stressed plants accumulate more proline to protect their cell membranes. The application of biostimulants such as the protein hydrolysate Naturamin WSP can alleviate some of the adverse effects caused by low temperature. Our results indicated an increased activity of guaiacol peroxidase (GPOD) in all plants treated with the biostimulant regardless of the temperature of cultivation. The mitigation of damages caused by chilling stress might be explained by an enhanced anti-oxidative defense, as demonstrated by the activity of guaiacol peroxidases and increased proline concentrations in Naturamin WSP-treated plants.
2022-09-23
Hamdia M. Abd El-Samad, Rania Mohamed Taha
The present experiments were performed to determine the effects of Zn (20 µM and 200 µM) and Ni (1 µM and 100 µM) on the growth and metabolic activities in the roots, shoots, and spikes of wheat ( Triticum aestivum L.) cv. Gimiza 11 grown under different salinity conditions. In addition to identifying the osmotic tolerance of wheat, the roles of Zn and Ni in alleviating osmotic stress were examined. The root was the organ most sensitive to osmotic stress, whereas the shoot was the most resistant, and the spike was the intermediate. These three organs negatively responded to increasing osmotic stress levels, as fresh and dry matter decreased, and related biochemical parameters were adversely affected. However, fresh and dry matter were generally elevated when plants were supplemented with Zn or Ni under increasing osmotic stress. The sensitivity of roots was associated with depletion in the concentrations of sugars and free proline, whereas soluble protein and amino acid levels were increased. The stress tolerance of shoots and spikes was accompanied by an increase in soluble sugars, soluble proteins, and proline, while amino acid levels increased in spikes only. The Na + and K + content in wheat plants increased with increasing NaCl-induced osmotic stress levels. In turn, the accumulation and partitioning of Na + and K + did not vary among the three organs, both at different salt concentrations and between Zn or Ni treatments. Moreover, the present results show that the concentrations of anthocyanins, flavonoids, and L-ascorbic acid increased under exposure to osmotic stress and did not change significantly under Zn or Ni treatments.
2022-07-21
Youssef Antoine Abou Obaid, Grigor Traykov Zehirov, Nadya Krasimirova Again-Stoyanova, Maria Ivanova Petrova, Rachelle Hanna Haddad, Fadi Sami Karam, Nidal Tabit Shaban, Rumyana Dimova Vassilevska-Ivanova
Saffron ( Crocus sativus L., Iridaceae) is a highly valued species in the food, medicinal, and nutraceutical industries as a coloring, flavoring, and therapeutic agent. Its productivity and flower production vary depending on different factors, including fertilizer treatment. This study was conducted to evaluate the effects of inorganic (NK) fertilizer combined with organic matter in different plant densities as well as the influence of split foliar fertilizer application on flower yield of saffron. The performance of saffron plants revealed that the combined application of inorganic fertilizer NK and vegetal organic matter (1%) was generally better than the effect of foliar treatment. Treatment with split foliar fertilizers at the recommended optimal concentration prolonged the flowering period of saffron plants.
2022-05-09
Messias de Carvalho, Wiktor Halecki, Katarzyna Możdżeń, Agnieszka Synowiec
The present study aimed to assess the allelopathic potential of four cereals: winter wheat ( Triticum aestivum L.), triticale ( ×Triticosecale Wittm.), spelt wheat ( Triticum spelta L.) and barley ( Hordeum vulgare L.) through a completely randomized (CR) design. The allelopathic effects of water extracts of different parts of the cereal plants (stem, leaf, and spike) at different concentrations (0.5%, 1.0%, 2.0%, and 4.0%) were evaluated on the seed germination and seedling growth. The germination rate, length, and dry weight of the shoot and root of the seedlings were measured. Ferulic acid was detected in all the cereals. The water extracts at 2.0% and 4.0% concentration had an allelopathic effect on the germination rate, shoot and root length of seedlings of spelt wheat, barley, and triticale, and the stem and leaf extracts affected the root and shoot length of winter wheat. The allelopathic effect of the dried powder of the cereals were evaluated in pot experiments. Both spelt wheat and triticale powder treatment at elevated CO 2 levels increased the dry weight of the root, as well as the length of the shoot and root of winter wheat. Furthermore, treatment with 4.0 g of dry cereal powder combined with an elevated level of CO 2 increased the shoot length, whereas the root length of winter wheat was unaffected. In summary, the combination of dry cereal powder with elevated CO 2 stimulates the initial growth of winter wheat.