Characterization of Tomato Genotypes for Important Fruit Quality Traits

An experiment was conducted using thirty-eight tomato genotypes to evaluate the performance of different morphological and biochemical traits and their genetic analysis. An analysis of variance showed a high level of variation among all genotypes. Chlorophyll content (1st leaf), number of seed/fruit, ascorbic acid content in red fruit, lycopene, and beta-carotene content in red fruit showed high heritability along with a high percentage of genetic advance, which indicates selection can improve these traits. Other traits show moderate heritability and a moderate GA%. For most characters, phenotypic coefficient variance is higher than genotypic coefficient variance, indicating the influence of the environment is greater than genetic influence. Red fruit weight shows a positive and significant correlation with yield/plant. Path coefficient analysis revealed that the soluble solid content of red fruit exocarp and endocarp had a direct positive effect on yield/plant. Principal component analysis showed six principal components contributing 77.45% of the total variability of different traits. Cluster analysis grouped 38 genotypes into five clusters, where clusters V and III had the maximum genotypes. The dendrogram showed cluster V had the highest amount of variation. Two-way cluster heat map showed five clusters for genotypes and two groups for variable. Mean performance showed genotype CL5915- 153 D4-3-6-0 has the highest yield/plant and the highest weight of red fruit; genotype TC0277 has high soluble solid content in endocarp of red fruit; and genotypes Bupribig and Homeastid were superior for ascorbic acid, lycopene and beta-carotene content, which can be considered superior genotypes having important fruit quality traits

Biochemical changes of rice genotypes against blast (Magnaporthe oryzae) disease and SSR marker validation for resistance genes

Rice blast caused by Magnoporthe oryzae is a major devastating fungal disease and represents a potential threat to world rice productions. However, information about the genetic and biochemical basis of disease tolerance is still limited. In this study, we tested the presence and diversity of resistant R genes using SSR markers, and the antioxidant enzymes catalase (CAT), ascorbate peroxidise (APX) and guaicol peroxidise (POD), activity and also the concentration of hydrogen peroxide (H2O2) and malondialdehyde (MDA) in resistant (BAUdhan 3) and susceptible (BRRIdhan 28) genotype. Molecular marker analysis reveals the presence of all ten studied resistant genes in BAUdhan 3. Among the markers studied, three markers namely RM224, RM72 and RM206 produce distinct band only in resistant genotype BAUdhan 3, which might be used to screen resistant genotypes. The enzymatic activity of APX, CAT and POD increased in the inoculated plant for both cultivars but the increase was more prominent for BAUdhan 3. The M. oryzae infections significantly increased the H2O2 content in BRRIdhan 28 and not much changed in BAUdhan 3. The MDA concentration was higher in the leaves of inoculated plants of BRRIdhan 28. The higher activities of APX and POD in the leaves of the inoculated plants of BAUdhan 3 resulted in lower H2O2 accumulation which can minimize the cellular damages possibly caused by reactive oxygen species. The result shows that the presence of more resistance genes and an effective antioxidative system in BAUdhan 3, which limits the damage caused due to fungal infection and thus contributes to greater resistance

The polyamine oxidase from lycophyte Selaginella lepidophylla (SelPAO5), unlike that of angiosperms, back-converts thermospermine to norspermidine

AbstractIn the phylogeny of plant polyamine oxidases (PAOs), clade III members from angiosperms, such as Arabidopsis thaliana PAO5 and Oryza sativa PAO1, prefer spermine and thermospermine as substrates and back-convert both of these substrates to spermidine in vitro. A clade III representative of lycophytes, SelPAO5 from Selaginella lepidophylla, also prefers spermine and thermospermine but instead back-converts these substrates to spermidine and norspermidine, respectively. This finding indicates that the clade III PAOs of lycophytes and angiosperms oxidize thermospermine at different carbon positions. We discuss the physiological significance of this difference