Title : Deciphering the impact of electrical conductivity on greenhouse cucumber quality: Insights from physiological responses and potassium transporter genes
Abstract:
Rising world population and higher per capita incomes anticipate increased demands for agricultural produces by the mid-21st century. To meet these needs extensive fertilisers, and pesticides are being used that directly or indirectly impacts global climate change. As a result, the issues arising from conventional agriculture could be tackled by growing nutrient efficient plants and effective agricultural practices. Greenhouse horticulture, a sustainable alternative to maximises resource use and return for vegetable production. Cucumber (Cucumis sativus cv. Lebanese and Continental), a widely grown vegetable is primarily cultivated in greenhouses. Therefore, greenhouse experiment was conducted at three different electrical conductivity levels (EC 1.0, 2.5 and EC 3.5) to evaluate its effect on productivity and quality of cucumbers. Statistical analysis performed on the collected data illustrated no significant effect on productivity and photosynthesis rate of cucumbers however, chlorophyll fluorescence established an inverse relationship with electron transport rate showing comparable differences between EC 1.0, EC 2.5, and EC 3.5. To obtain response of potassium transporter genes at different EC levels relative expression analysis on cucumber leaves and fruits revealed interesting participation of genes like KEA3, KUP5, KEA5, KEA4, HAK5, KUP11, KAT3 affecting fruit quality and overall morphology of crop. Post-harvest results revealed highest percentage of weight loss in EC 1.0 of Lebanese and Continental at 2°C and 7°C. Primary metabolites including carbohydrates, sugars and amino acids plays a significant role in maintaining the fruit quality of cucumber by establishing strong link with physiological parameters including photosynthesis and stomatal conductance. In future metabolomics study on fruits of cucumber will help in identifying the biological compounds essential for growth and development, that have a direct impact on yield and biochemical constituents of plants. These results can be taken as recommendations for better quality and yield enhancement by using low fertigation levels to achieve more resource-sustainable and profitable cucumber production in greenhouses.
Keywords: Protected cropping; sustainable production; shelf life; postharvest; potassium; metabolites
