Utilization of organic-residues as potting media: Physico-chemical characteristics and their influence on vegetable production.

Soilless agriculture is acknowledged worldwide because it uses organic leftovers as a means of supporting intensive and efficient plant production. However, the quality of potting media deteriorates because of lower nutrient content and excessive shrinkage of most organic materials. A current study was undertaken to identify the optimal blend of locally available organic materials with desirable qualities for use as potting media. Therefore, different ingredients, viz., Pinus roxburghii needles, sugarcane bagasse, and farmyard manure were used alone or in combination as potting media to test their suitability by growing spinach as a test crop. Results showed that an increase in Pinus roxburghii needles and sugarcane bagasse decreased medium pH and electrical conductivity. Higher pH and electrical conductivity were recorded for the treatments having a higher farmyard manure ratio (≥50%) in combination. Except for pine needles 100%, pH and electrical conductivity were in the recommended range. The growth attributes include, leaves plant-1, shoot length, fresh- and dry shoot weight along with plant macronutrients (nitrogen, phosphorous, and potassium) and micronutrients (iron, copper, manganese, and zinc) content were higher in treatment pine needles 50%+farmyard manure 50% followed by pine needles 25%+farmyard manure 50%+sugarcane bagasse 25%. Moreover, the particular treatment of pine needles 50%+farmyard manure 50% exhibited the highest concentrations of macro- (nitrogen, phosphorus, and potassium) as well as micronutrients (iron, copper, manganese, and zinc) in the potting media following the harvest. This study highlights the potential of utilizing agro-industrial litter/waste as a soilless growing medium for spinach production under greenhouse conditions. When employed in appropriate proportions, this approach not only addresses disposal concerns but also proves effective for sustainable cultivation. Further research is needed to investigate the use of these wastes as potting media by mixing various particle-size ingredients.

Cloning and functional analysis of the DXR gene and promoter region in Osmanthus fragrans var. semperflorens.

The precise biological function and activity of the deoxylulose-5-phosphate reductoisomerase (DXR) gene and its promoter in Osmanthus fragrans var. semperflorens remain unclear, even though OfDXR is known as the crucial enzyme involved in plant terpenoid synthesis. This study aimed to shed light on the role and activity of the OfDXR gene and its promoter in O. fragrans var. semperflorens by employing RACE-PCR and Hi-TAIL-PCR techniques for the cloning of the gene and promoter sequence from the petal tissue. Subsequently, genetic transformation and histochemical staining methods were utilized to analyze their function and activity. The OfDXR gene exhibited a DNA sequence length of 5241 bp, encompassing 12 exons and 11 introns. The corresponding cDNA sequence of the OfDXR gene was 1629 bp, encoding 474 amino acid residues. Expression analysis revealed that the OfDXR gene was predominantly active in the petals during the early full blooming stage. Overexpression of the OfDXR gene in Arabidopsis plants at the primary or full blooming stage led to an augmentation in the total terpenoid content. Furthermore, the promoter sequence of the OfDXR gene spanned a length of 1174 bp and contained conserved regulatory/response elements, demonstrating functional activity. These findings indicate that the OfDXR gene plays a pivotal role in terpenoid synthesis, while its promoter exhibits robust activity.