Genetic and Phenotypic Diversity in Downy-mildew-resistant Sorghum (Sorghum bicolor (L.) Moench) Germplasm     

V. Kamala  P. J. Bramel  S. Sivaramakrishnan  S. Chandra  Seetha Kannan  S. Harikrishna  D. Manohar Rao 《Genetic Resources and Crop Evolution》2006,53(6):1243-1253

Genetic and phenotypic diversity among randomly selected 36 downy-mildew-resistant sorghum accessions were assessed, the former using 10 simple sequence repeat (SSR) marker loci and the latter using 20 phenotypic traits. The number of alleles (a _j ) at individual loci varied from five to 14 with an average of 8.8 alleles per locus. Nei's gene diversity (H _j ) varied from 0.59 to 0.92 with an average of 0.81 per locus. High gene diversity and allelic richness were observed in races durra caudatum (H _j = 0.76, a _j = 4.3) and guinea caudatum (H _j = 0.76, a _j = 3.8) and in east Africa (H _j = 0.78, a _j = 7.2). The regions were genetically more differentiated than the races as indicated by Wright's F _st. The pattern of SSR-based clustering of accessions was more in accordance with their geographic proximity than with their racial likeness. This clustering pattern matched little with that obtained from phenotypic traits. The inter-accession genetic distance varied from 0.30 to 1.00 with an average of 0.78. Inter-accession phenotypic distance varied from 0.01 to 0.55 with an average of 0.33. Eleven accession-pairs had phenotypic distance of more than 0.50 and genetic distance of more than 0.70. These could be used as potential parents in a sorghum downy mildew resistance-breeding program.  相似文献   

Comparison of Cadmium Ion Adsorption on Various ACTIVATED CARBONS     

Nagarethinam Kannan  Gurusamy Rengasamy 《Water, air, and soil pollution》2005,163(1-4):185-201

Studies on the removal of cadmium(II) ions from aqueous solutions by adsorption on various activated carbons [commercial activated carbon (CAC) and chemically prepared activated carbons (CPACs) from raw materials such as straw, saw dust and datesnut] have been carried out with an aim to obtain information on treating effluents containing Cd(II) ions. Factors influencing the adsorption of Cd(II) ions from aqueous solution by ACs have been investigated by following a batch adsorption technique at 30± 1 ^°C. The percentage removal increased with decrease in initial concentration and particle size of CPACs and an increase in contact time, dose and initial pH of the solution. Adsorption process was inhibited by the added electrolytes. The adsorption data were fitted with the Langmuir, Dubinim–Radushkevich and Freundlich isotherms and first-order kinetic equations viz., first-order, Lagergren and Bhattacharya–Venkobachar equations and intra-particle diffusion model. The kinetics of adsorption is first order with intra-particle diffusion as one of the rate determining steps. Thermodynamic parameters were obtained from equilibrium constants measured at 30, 35 and 40 ^°C (Error = ± 1 ^°C). Results of the studies on adsorption of Cd²⁺ ions from simulated wastewater were compared with that of CAC and Tulsion CXO-9(H), a commercial ion exchange resin/cationic resin (CR). Straw carbon showed the maximum adsorption capacity towards Cd²⁺ ions and a high value of rate constant of adsorption. Straw carbon is an alternative low-cost adsorbent to CAC.  相似文献   

Influence of irrigation with pulp and paper mill effluent on soil chemical and microbiological properties     

K. Kannan  G. Oblisami 《Biology and Fertility of Soils》1990,10(3):197-201

Summary Irrigation of sugarcane crops with combined pulp and paper mill effluent increased soil pH, organic C, N, P, and K. Over a period of 15 years effluent application increased exchangeable Na by 4.5-fold compared with control soil (well-water irrigated), which ultimately elevated the Na adsorption ratio of the soils. The combined effluent irrigation increased the soil populations of bacteria, actinomycetes, fungi, rhizobia, and yeasts. The populations of soil microorganisms were higher after 15 years of effluent treatment, followed by 3, 2, and 1 year of effluent treatment; these populations were directly proportional to soil organic C and to the available nutrient status of the soils. Regular monitoring of microflora showed a considerable change in the populations from one sampling month to another. Soil samples, including the control, collected in May (summer) showed maximum counts of bacteria, fungi, rhizobia, and yeasts.  相似文献   

Dry matter production, chlorophyll, protein contents and foliar nutrient concentration inPeltophorum ferrugineum andAlbizia lebbeck under nursery conditions     

D. Kannan  Kailash Paliwal 《Forest Ecology and Management》1992,50(3-4):265-273

This study assesses the dry matter production, chlorophyll, soluble protein and macronutrients inPeltophorum ferrugineum andAlbizia lebbeck. The parameters were measured at 30-day intervals for 180 days in fertile soil without moisture stress and in the natural nursery condition.Albizia lebbeck exhibited more dry matter production, chlorophyll, soluble protein and macronutrients thanP. ferrugineum. A significant positive correlation was observed between dry matter production, leaf area, leaf dry weight and soluble protein for both the tested seedlings. The possible reasons for the observed differences in the biomass production, biochemical contents and nutrient concentration between the two seedlings are discussed.  相似文献   

De novo transcriptome assembly and development of EST-SSR markers for Pterocarpus santalinus L. f. (Red sanders), a threatened and endemic tree of India     

Agasthikumar  Sindhu  Patturaj  Maheswari  Samji  Aghila  Aiyer  Balasubramanian  Munusamy  Aiswarya  Kannan  Nithishkumar  Arivazhagan  Vijayakumar  Warrier  Rekha R.  Ramasamy  Yasodha 《Genetic Resources and Crop Evolution》2022,69(7):2469-2484

Genetic Resources and Crop Evolution - The endemic and precious tree Pterocarpus santalinus L. f. (Red sanders) is a drought hardy species for conservation in peninsular India due to its...  相似文献   

Plasmalemma: The Seat of Dual Mechanisms of Ion Absorption in Chlorella pyrenoidosa     

Kannan S 《Science (New York, N.Y.)》1971,173(4000):927-929

Dual mechanisms of absorption of rubidium were demonstrated in a nonvacuolate unicellular alga, Chlorella pyrenoidosa, in both the light and the dark. The two mechanisms were sensitive to metabolic inhibitors. At high concentrations rubidium enhanced the respiration of Chlorella cells. The findings support the conclusion that the mechanisms of rubidium absorption in both the low and high concentration ranges are active processes and reside in the plasmalemma.  相似文献   

Perfluorinated compounds in human blood, water, edible freshwater fish, and seafood in China: daily intake and regional differences in human exposures   总被引：3，自引：0，他引：3  

Zhang T  Sun H  Lin Y  Wang L  Zhang X  Liu Y  Geng X  Zhao L  Li F  Kannan K 《Journal of agricultural and food chemistry》2011,59(20):11168-11176

Despite the growing public interest in perfluorinated compounds (PFCs), very few studies have reported the sources and pathways of human exposure to these compounds in China. In this study, concentrations of 10 PFCs were measured in human blood, water (tap water and surface water), freshwater fish, and seafood samples collected from China. On the basis of the data, we calculated daily intakes of PFCs, regional differences in human exposures, and potential risks associated with ingestion of PFCs from diet, drinking water, and indoor dust for the Chinese population. Perfluorooctane sulfonate (PFOS) was the most predominant PFC found with a mean concentration of 12.5 ng/mL in human blood from Tianjin and 0.92 ng/g wet wt in freshwater fish and seafood; perfluorooctanoic acid (PFOA) was the major PFC found in drinking water at a concentration range of 0.10 to 0.92 ng/L. The estimated daily intake of PFOS and PFOA via fish and seafood consumption (EDI(fish&seafood)) ranged from 0.10 to 2.51 and 0.13 to 0.38 ng/kg bw/day, respectively, for different age groups (i.e., toddlers, adolescents and children, and adults) from selected locations (i.e., Tianjin, Nanchang, Wuhan, and Shenyang). The EDI(fish&seafood) of PFCs decreased (p < 0.05) with age. The estimated daily intake of PFOS and PFOA via drinking water consumption (EDI(drinking water)) ranged from 0.006 to 0.014 and 0.010 to 0.159 ng/kg bw/day, respectively. Comparison of EDI(fish&seafood) and EDI(drinking water) values with those of the modeled total dietary intake (TDI) of PFCs by adults from Tianjin, Nanchang, Wuhan, and Shenyang showed that contributions of fish and seafood to TDI of PFOS varied depending on the location. Fish and seafood accounted for 7%, 24%, 80%, and 84% of PFOS intake in Nanchang, Shenyang, Wuhan, and Tianjin, respectively, suggesting regional differences in human exposure to PFOS. Drinking water was a minor source of PFOS (<1%) exposure in adults from all the study locations.  相似文献   

Differential zinc uptake and transport in sorghum varieties suited for different moisture regimes     

Saradha Ramani  Seshadri Kannan  Arvind S. Nirale 《Journal of plant nutrition》2013,36(4):337-351

Zinc absorption and transport were examined in M‐35 a drought resistant, and M‐47, a drought susceptible sorghum (Sorghum bicolor L. Moench) cultivar. Excised roots were employed to study the mechanisms of uptake at cellular level in these varieties.

The absorption over 0 to 130 μM ZnCl₂ followed a biphasic pattern with a second rise at 90 μM, a feature which was not observed in the absorption by roots of intact seedlings. While there were no differences in the patterns of absorption in the two cultivars, the transport to shoot in M‐35 followed a slower rate up to 90 μM than that in M‐47. When Zn uptake was examined for 6 hours, the absorption and transport showed a number of changes in phase, which were running parallel. The transport of Zn followed a higher rate in M‐47 than that in M‐35.

Phosphate decreased the uptake and also transport of Zn in both the varieties. However, Zn inhibited phosphate absorption and transport in intact seedlings differentially amongst the varieties. Further, the inhibition of Zn uptake was much less in M‐35 than in M‐47, a feature which will perhaps facilitate survival of M‐35 under water stress, a condition which would also limit phosphate availability.  相似文献   

Studies on Fe deficiency stress response in three cultivars of sunflower (helianthus annuus L.)     

Seshadri Kannan 《Journal of plant nutrition》2013,36(8):1203-1212

Iron deficiency stress was induced in cultivars, PKV‐7237, Morden and EC‐68414 of sunflower (Helianthus annuus L) by first growing them in full nutrient medium and transferring to minus Fe medium after a month. The minus Fe nutrient medium was changed again at 13 and 26 days. The change in pH and the degree of chlorosis were recorded. It was found that the pH decreased rapidly in all cultivers from 6.4 to 3.8 in 5 days. The cv. Morden was found more tolerant to the stress than others. Furthermore, the flavinlike pigments as shown by the yellow coloration of the medium were more intense in PKV than in Korden, and were very much less in EC. It was also noted that the pH reduction was non‐redumptive, a feature observed even after transferring twice to fresh minus Fe medium adjusted to pH 6.4. The results of the experiments showed that as long as Fe absorbed from the pre‐stress medium was available in the root, the chlorosis was not severe; but once it was nearly depleted, chlorosis appeared and persisted for a long time.  相似文献   

Distribution of prion protein genotypes in breeds of sheep in New Zealand     

MA Lee  TR Manley  BC Glass  RM Anderson  SJ Wilson  JS O'Keefe 《New Zealand veterinary journal》2013,61(5):222-227

AIM: To use an established high through-put genotyping procedure to gain an estimate of the frequency of alleles of the prion protein (PrP) gene in some common sheep breeds in New Zealand.

METHODS: Using a genotyping procedure based on matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF), DNA samples from 3,024 sheep from New Zealand, including breeds such as Romney, Texel, Coopworth, Merino and mixedbreed, were isolated, genotyped and the results analysed.

RESULTS: The 15 scrapie genotypes commonly reported, and derived from the five commonly reported allelic variants (ARR, ARQ, AHQ, ARH and VRQ), were all observed in the samples analysed. The estimates were indicative of the frequencies in the population of alleles present in breeds of sheep in New Zealand. There was a significant difference between the frequencies of alleles between breeds, but the ARQ, followed by the ARR allele, were, except in Carwell sheep, the most common alleles present.

CONCLUSION: This study gave an indication of the percentages of PrP gene alleles in sheep in New Zealand, including data previously unreported from breeds in this country. It is of interest because of the relatively large size of the sheep population in New Zealand compared with many countries, and it provides some useful information on the genetic susceptibility or resistance of the sheep population in New Zealand to scrapie. The frequencies of the alleles can be different for an individual breed compared between countries.  相似文献