Evaluation of Easy and Economic Protocols for High Quality Genomic DNA Extraction and Sex Determination in Papaya Using SCAR Markers

Rapid and precise identification of three sex types (male, hermaphrodite and female flowers) is the key in achieving good returns in papaya (Carica papaya L.) cultivation. This study presents a simple, reliable, fast and cost-efficient DNA isolation protocol and a rapid and precise method of sex determination in papaya. Three DNA isolation protocols viz., CTAB method, Modified Dellaporta method and BioBasic DNA isolation kit were comparatively evaluated for their simplicity, economic, DNA quantity and purity. Among them, CTAB method was regarded as relatively economic, with a cost of Rs. 11.80943 per sample with higher amount of DNA (4667.4 µg/ µl). However, it was noticed that DNA isolation with the BioBasic kit was fastest method, which took only 6 hours 7 minutes. On the other hand, relatively better DNA purity was noticed with the Modified Dellaporta method (average ratio of absorbance at 260 nm and 280 nm range between 1.8-2.0) and yielded clear, intact and distinct DNA bands. Hence, Modified Dellaporta method is suggested as an ideal DNA isolation protocol for papaya. Molecular markers (such as SCAR derived from RAPD T12, W11, NAPF-2 and PKBT-4) were employed in this study to identify the sex type and they have successfully distinguished between male and hermaphrodite plants in both dioecious and gynodioecious varieties; especially, NAPF-2 has successfully distinguished male in dioecious varieties. Evaluation of different kinds of molecular markers has shown that the SCAR marker T12 can be used as reliable marker for rapid and precise identification of papaya sex type.

Foliar Application of Liquid Micronutrient Formulation for Improving Quality of Panner Grapes

Micronutrient deficiencies play a significant role in impacting the yield and quality of grapes in vineyards. To address the deficiencies, a field study was conducted during the summer, of 2022 by using foliar micronutrient mixtures in three different concentrations (0.5%, 1.0%, and 1.5%), with one spray during pre-fruit set stage and twice at pre-fruit set/berry growth stages. The study aimed to investigate the effects of foliar micronutrient application on the biochemical quality characteristics of the Muscat Hamburg grapevine cultivar. The results of the study showed that the application of micronutrients spray showed a beneficial impact on all the yield parameters, such as number of bunches per vine (ranging from 28 to 44), the yield per vine (varied from 5.56 to 6.55 kg per vine), with overall yield range between 20.7 to 24.2 t ha-1. The biochemical properties of the berries, including sugars (reducing, non-reducing, and total sugars), juice pH and content, TSS (Total Soluble Solids), Titrable acidity, and berry firmness, were found to be high in grapevines sprayed at 1.0% twice. Results showed that total sugars ranged from 15.2% to 10.7%, with a juice pH of 3.47 to 3.94, juice content of 83.5 to 95.5%, and TSS from 15.6 to 17.40º Brix. Regarding the Titrable acidity and firmness of the berries, the outcomes showed a range of 0.92% to 1.14% for acidity and 9.4 to 12.9 N for firmness. Findings from the study clearly showed that applying 1.0% micronutrients twice at fruit-set and berry stages increased yield and improved quality indices of Paneer grapes.

Role of Exogenous Melatonin in Enhancing Shelf Life of Traditional Banana Varieties

Aims: An experiment was conducted to examine the effect of various concentrations of melatonin on post harvest weight loss and shelf life of three traditional banana varieties viz. Ney Poovan, Nendran and Red Banana.Study Design: Completely Randomized Design.Place and Duration of Study: Post Graduate laboratory, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore during 2022.Methodology: Banana hands were dipped in 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mM melatonin for 15 minutes and were stored at ambient temperature. The hands dipped in water were treated as control. Observations on physiological weight loss and shelf life were recorded till the fruits remained marketable.Results: The results depicted that fruits immersed in 1.0 and 1.5 mM melatonin for 15 minutes recorded lower weight loss (31.56, 30.55 and 24.90%) on 11th, 11th and 12th day of storage and longer shelf life by 3, 2.67 and 2.67 days in Ney Poovan, Nendran and Red Banana respectively.Conclusion: The effects of melatonin were due to its efficiency in reducing transpiration and respiration and thereby lowering weight loss. The lowered metabolic activity not only mitigated weight loss but also maintained firmness and turgidity of the fruits and thereby prolonging the storability. It was evident from the results that melatonin treatment could be a good practice for extending postharvest life of banana by reducing the physiological loss in weight simultaneously maintaining the appearance.

Isolation of inulinase producing bacteria from sugarcane soil.

Microbial inulinases have a great potential for industrial use in the production of fructose from inulin. Optimization of the growth parameters of the microbes is essential to obtain inulinase in sufficient quantity. The present work aimed to obtain inulinase from natural strains isolated from sugarcane fields and to optimize its growth parameters. In a total of ten isolates, four organisms Bacillus subtilis, Lactobacillus casei, Pseudomonas aeruginosa, and Achromobacter sp. were identified as efficient inulinase producers. The optimum temperature and pH of these organisms were found to be 40°C and pH 5 respectively. Inulin was observed to be the suitable carbon source for these organisms. The molecular weight of this enzyme was estimated at 45 KDa using SDS-PAGE. On thin layer chromatography inulin hydrolysis showed mono and disaccharides as the main end products. The highest enzyme activity was obtained from Achromobacter spp. of 333 U/L at 22nd hour which showed exo-inulinase type.