Profiling of major biochemical compounds for identification of nutritionally rich genotypes in mango

Aim: Mango is a major fruit crop grown in India with wide variability for fruit colour, size, shape and fruit quality. The main objective of this study was profiling of mango genotypes and their genetic estimates for major biochemical compounds to identify superior genotypes as parents for developing nutritionally rich hybrids in future. Methodology: Fifty mango varieties were analysed for biochemical compounds such as total antioxidants, total phenols, total flavonoids and total carotenoids. The L*, a*, b* values were recorded for pulp colour, and genetic estimates were also worked for genetic parameters such as genotypic variance, phenotypic variance, GCV, PCV, heritability and genetic advance. Correlation matrix for major biochemical compounds and L*, a*, b* values were also calculated. Results: The present study revealed the presence of wide genetic variability in mango gene pool for biochemical compounds and pulp colour. The total phenolics ranged from 24.44 to 148.33 mg 100g-1 of pulp, total flavonoids 10.33-49 mg 100g-1, total carotenoids 0.48-7.50 mg 100g-1 and total antioxidants 0.14-1.59 µmol Trolox 100g-1 of pulp. The future genetic estimates showed that the phenotypic coefficient of variation (PCV) for all the characters was slightly higher than genotypic coefficient of variation (GCV), indicating the presence of environmental influence to some degree in the phenotypic expression of characters. However, the difference between PCV and GCV for all the traits was narrow suggesting that the traits were less influenced by environment. The broad sense heritability (H2b) for all the compounds was high which indicates the phenotype of that trait strongly reflects its genotype. Interpretation: High values of PCV, GCV and heritability for total antioxidants, total phenols, total flavonoids and total carotenoids indicated high genetic variability and better scope for selection and improvement through hybridization.

Studies on Physical, Chemical and Amorphous Constituents of Associated Red and Black Soils: A Case Study in Hatti Schist Belt of North Karnataka.

Associated red and black soils of the transect from Hira region of Hatti schist belt were studied for their properties. Soils were moderately deep to deep, reddish brown (5YR 3/4) to dark black (10YR3/2), clay in texture. The pH ranged from 7.56 to 7.7, EC from 0.4 to 0.44dSm-1, low to medium in organic carbon, moderate in CEC (40.1 – 54.3 c mol (p+) kg-1). Free iron oxides ranges from (0.6-3.2%), Na2CO3 extractable free silicon ranges from (0.4-3.1%) and Na2CO3 extractable free aluminium ranges from (0.2 - 2.5%).

Pathogenicity Tests and Evaluation of Efficacy of Fungicides Against Rhizoctonia Bataticola, the Causal Agent of Dry Root Rot of Chickpea.

The pathogen was identified based on its mycelial and sclerotial characters and pathogenicity test was proved by soil inoculation method. Efficacy of two non systemic fungicides (copper oxychloride and captan), two systemic fungicides (hexaconazole and tebuconazole) and one antifungal antibiotic validamycin each at different concentrations were tested against Rhizoctonia bataticola, incitant of dry root rot of chickpea under in vitro conditions. The fungicides copper oxychloride, captan, hexaconazole and tebuconazole were found to be highly effective (100%) in inhibiting the mycelial growth of the highly virulent pathogen at all the concentrations tested.

Mycoparasitism of Trichoderma Spp. on Rhizoctonia Bataticola, the Causal Agent of Dry Root Rot of Chickpea.

Mode of parasitism between Trichoderma and Rhizoctonia bataticola was examined under a microscope. Formation of several loops and coiling around the hyphae of pathogen, forming a thick compact rope like structure followed by rupturing, twisting and leakage of hyphal protoplasm, air bubbling inside the cytoplasm, breaking of cytoplasmic continuity, aggregation of cytoplasm within cell leading to severe vacoulation were observed at later phase of interaction.

Integrating biostatistics and experimental physiology: students' perceptions and future scope.

The use of biostatistics in experimental physiology is recognised by researchers. However, there has been no concerted attempt to integrate biostatistics into the undergraduate experimental physiology programme. This paper describes one such initiative. The student's response to the exercise was largely positive; it enabled them to describe and interpret data more effectively and understand the experiments more completely. The attitudes of the students to the exercise and their performance at a statistics examination at the end of the exercise was determined by a number of parameters, including prior statistical knowledge, general academic performance and the extent to which they liked mathematics. However, even those students who disliked mathematics indicated that they appreciated the value of the exercise. The results indicate the need to integrate biostatistics into the undergraduate physiology course.