ABSTRACT
The effect of Aloe vera (AV) gel coating was studied on antioxidant enzymes activities, oxidative stress, softening and associated quality attributes of persimmon fruits. The fruits were coated with 0 and 50% AV-gel coating and stored for 20 days at 20 ± 1 ºC. AV-gel coated fruits exhibited considerably less weight loss, hydrogen peroxide level, electrolyte leakage and malondialdehyde content. AV-gel coated fruits had significantly higher ascorbate peroxidase, peroxidase, superoxide dismutase and catalase activities. In addition, AV-gel coating suppressed pectin methylesterase, polygalacturonase and cellulase activities and showed higher ascorbic acid, DPPH scavenging antioxidants and phenolics, and lower sugars and carotenoids. To the best of our knowledge, these results are the first evidence that AV-gel coating modulates the activities of cell wall degrading enzymes to delay ripening in climacteric fruits. So, AV-gel coating prohibited the onset of senescence by activating enzymatic antioxidant system, accumulating bioactive compounds and suppressing cell wall degradation. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05412-5.
ABSTRACT
Nitrogen (N) is a macronutrient desired by crop plants in large quantities. However, hiking fertilizer prices need alternative N sources for reducing its requirements through appropriate management practices. Plant growth promoting rhizobacteria (PGPR) are well-known for their role in lowering N requirements of crop plants. This study assessed the impact of PGPR inoculation on growth, allometry and biochemical traits of chili under different N doses. Two PGPR, i.e., Azospirillum 'Er-20' (nitrogen fixing) and Agrobacterium 'Ca-18' (phosphorous solubilizing) were used for inoculation, while control treatment had no PGPR inoculation. Six N doses, i.e., 100, 80, 75, 70, 60 and 50% of the N required by chili were included in the study. Data relating to growth traits, biochemical attributes and yield related traits were recorded. Interaction among N doses and PGPR inoculation significantly altered all growth traits, biochemical attributes and yield related traits. The highest values of the recorded traits were observed for 100% N with and without PGPR inoculation and 75% N with PGPR inoculation. The lowest values of the recorded traits were noted for 50% N without PGPR inoculation. The PGPR inoculation improved the measured traits compared to the traits recorded noted in same N dose without PGPR inoculation. Results revealed that PGPR had the potential to lower 25% N requirement for chili. Therefore, it is recommended that PGPR must be used in chili cultivation to lower N requirements.