‘Kinnow’ is a hybrid mandarin, developed at California (USA) but could not become successful there. However, it revolutionized citrus industry in India, Pakistan and Bangladesh. Recent reports indicate that like other citrus fruits, it also suffers from juice-sac granulation but exact cause of this malady is not known. Fully-mature ‘Kinnow’ fruits were harvested and observations on some physical and biochemical attributes were recorded and their relationship was established with occurrence of granulation. About 12.8 % ‘Kinnow’ fruits were affected by juice-sac granulation. Granulated fruits had higher average weight (178 ± 2.26 g), peel thickness (3.72 ± 0.23 mm), and less soluble solids concentrates (7.4 ± 0.21 %) than non-granulated fruits. Granulated fruits exhibited lower concentrations of total phenolics compounds (4.3 ± 0.56 mg 100−1 g gallic acid equivalent fresh weigh) and antioxidants activity (1.78 ± 0.29 μmol Trolox g−1 FW) but produced higher rates of carbon dioxide and ethylene, and exhibited higher activities of senescent-related enzymes such as lipoxygenase (LOX) (1.3 ± 0.31 μmoles min−1 g−1 FW) and pectin methylesterase (PME) (0.52 ± 0.12 μmol of NaOH g−1 FW min−1) and had strong relationships with the occurrence of granulation. From this study, it can be concluded that total phenolics compounds, antioxidants and PAL enzyme activity have strongly negative co-relation; whereas, senescent-related enzymes such as LOX, and PME and rates of respiration or ethylene evolution have strongly positive relationships with the occurrence of granulation in ‘Kinnow’ mandarin.
1 May 2005 in Genetic Resources and Crop Evolution
Guava (Psidium guajava L.) is an open-pollinated crop having 25-40% dissimilarity index which promotes heterozygosity and adds new cultivars. Morpho-genetic characterization of 37 guava accessions was carried out for genetic variability and structure of guava germplasm located in Punjab province, Pakistan. Principal Component analysis (PCA) was subjected to analyze the morphological diversity and for genetic analysis we applied cluster analysis, using the PyElph software. PCA distributed thirty one traits into six components and first two components accounted 39.5% of total variation. A dendrogram constructed on the basis of morphological traits which showed 34% dissimilarity index among thirty seven guava accessions and divided them into 6 groups. For genetic characterization 18 microsatellites were used, the size of reproducible and scorable bands ranged from 150 to 320 bp. The 18 primer pairs amplified 85 alleles with an average number of 4.7 alleles per locus and no more than two displayed bands (nuclear SSR loci). The phylogenetic tree based on molecular analysis showed 50% dissimilarity index among selected guava accessions and separated them into 4 groups.
Drought, in conjunction with high temperature, is an important environmental constraint to cotton production. Development of cotton varieties with increased tolerance against adverse environmental conditions has been proposed as effective strategy for ensuring reliable yields. In the present study, 30 simple sequence repeat (SSR) primers were used to estimate genetic divergence among 22 cotton genotypes for drought stress tolerance. Genetic diversity is a prerequisite for developing drought resistant cotton genotypes. Eleven SSR primers out of 30 were able to discriminate among the cotton genotypes, implying that 37% of the primers were informative. In total, 41 alleles were detected, with an average of 3.72 alleles per primer. The number of alleles per locus ranged from one (JESPR-284) to six (JESSPR-302), and the allelic diversity in the experimental material was 0.40. Genetic similarity coefficients ranged from 0.87-1.00. The result of principal component analysis confirmed the clustering of 21 cotton genotypes in two groups leaving one genotype (CIM-109) ungrouped. Overall, genetic diversity among the 22 cotton genotypes was low. More polymorphic SSR markers are needed to explore the workable genetic variation among the screened cotton genotypes in future studies.
The aflatoxins are a group of chemically similar poisonous, carcinogenic fungal secondary metabolites produced by , , and , which are abundant in warm and humid regions of the world. They are probably the most intensively researched toxins in the world due to their carcinogenic and mutagenic effects. Aflatoxins have also been identified as a potential biological weapon for food and water contamination. The four major aflatoxins commonly isolated from different foods and feed stuffs are AFB1, AF B2, AFG1, and AFG2. Aflatoxin contamination of food and feed has gained global significance as a result of its deleterious effects on human as well as livestock health including gastrointestinal dysfunction, reduced feed utilization, anemia, jaundice, liver damage and immunity suppression. The profitability and marketing of various agricultural products are adversely affected by either contamination of aflatoxins or aflatoxin‐producing fungi. The foods at highest risk of aflatoxin contamination are maize, chilies, peanuts, and cotton seeds. There are various physical, chemical, and natural methods investigated to prevent aflatoxin production and the growth of aflatoxin‐producing fungus in various agricultural products. Here, we describe various natural plant extracts that would be potential source of controlling aflatoxin production in agricultural products.
31 December 2022 in SABRAO Journal of Breeding and Genetics