Intact roots promote shoot regeneration from hypocotyl independent of exogenous plant growth regulators in eggplant in vitro

Abstract: Eggplant (Solanum melongena) seedlings cultured in vitro were excised at the center of the hypocotyl to generate decapitated seedlings with intact roots. This modification of the complete decapitation method (CDM) developed in vivo b

Cucumber (<i>Cucumis sativus</i> L.) Growth and Productivity under Solar Radiation-Based Quantitative Nutrient Management in Hydroponic System

Grafted cucumber plants were grown in a new hydroponic system (“Kappa Land”, Mitsubishi Chemical Aqua Solutions, Co., Ltd., Tokyo, Japan). Two different nutrient management methods were applied to the plants as treatments: Electrical Conductivity-based Management (ECM) and Quantitative Nutrient Management (QNM). During the growth period, we examined plant growth characteristics and productivity, fruit growth characteristics and quality, and nutrient use characteristics. The results revealed that the QNM technique significantly reduced the nutrient supply rate per plant for Ca2+, SO42−, and N by 28.5%, 25.5%, and 23.3%, respectively. Similarly, the absorption rates per plant of SO42−, K+, and PO43− were reduced by 17.8%, 11.9%, and 10.9%, respectively. However, N, Ca2+, and Mg2+ absorption rates slightly increased in the QNM treatment. The nutrient wastes generated per kilogram of produced fruits were also reduced by 66.4%, 60.7%, and 30.2% for N, Ca2+, and SO42−, respectively. Although the QNM technique reduced the plant’s leaf area, it significantly increased its total length by 9.4%. The total and marketable yields were not significantly different between the ECM (9.0 and 8.0 kg plant−1) and QNM (9.1 and 8.2 kg plant−1) treatments. However, the QNM treatment produced the highest total dry matter of 617 g plant−1, surpassing the ECM treatment by 6.9%. On the other hand, differences in nutrient management methods did not significantly affect fruit quality, including total soluble solids, water content, skin color, size, and shape. These results suggest that with the QNM method, it is possible to produce quality cucumbers with high nutrient use efficiency while protecting the environment from nutrient wastes

Role of Mineral Nutrients in Plant Growth Under Extreme Temperatures

Food productivity is decreasing with the drastic increase in population, while it is expected that the global population will be nine to ten billion in 2050. Growth, production, and development on whole plant, cell, and subcellular levels are extremely affected by environmental factors particularly with the extreme temperature events (high- or low-temperature stress). Increase in the fluidity of lipid membrane, protein accumulation, and denaturation are the direct effects of high temperature on a plant. Membrane integrity loss, protein deprivation, protein synthesis inhabitation, and inactivation of mitochondrial and chloroplast enzymes are the indirect effects of high temperature. Similarly, the oval abortion, alteration of the pollen tube, reduction in fruit set, pollen sterility, and flower abscission are the consequences of low temperature at the time of product development, which in turn lowers the yield. The judicious nutrient management is essential for improving the plant nutrition status to mitigate the drastic effects of temperature stress as well as for sustainable plant yield under extreme temperature events, because nutrient deficiency results in growth and development problems in 60% cultivars worldwide. Additionally, effective nutrient management increases the temperature stress tolerance in plants. Therefore, the appropriate nutrient application rates and timings are imperative for alleviating the heat stress in plants and can serve as an effective and decent strategy. To minimize the contrasting effects of the environmental stresses, particularly heat stress, several examples of the supplemental applications of N, P, K, Ca, Mg, Se, and Zn are given in detail in this study, to observe how these nutrients reduce the effects of temperature stress in plants. This study concluded that judicious nutrient management minimizes the heat stress and increases the growth and yield of plants