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Haploid plants were regenerated in vitro from unpollinated ovules of niger (Guizotia abyssinica (L. f.) (Cass.) on Murashige and Skoog nutrient medium (MS) supplemented with 10 μM naphthaleneacetic acid or 10 μM NAA +
1.5 μM kinetin and 30 g/l sucrose. Gamborg (B5) medium was the best for plant regeneration (in comparison with MS, Nitsch
and Nitsch (NN), and Chu (N6) media) from cultured ovules, and 6.66 and 7.33 ovules of JNC-6 and Ootacamund cultivars were
involved in direct plant regeneration on this medium. Matured ovules (ovules collected one day before anthesis or on the day
of anthesis) only responded to cultural regimes and involved in direct plantlet development. Cytological preparation of root
tips and chloroplast counts in the guard cells of leaf stomata of regenerated plants confirmed their haploid nature.
This text was submitted by the authors in English. 相似文献
3.
Isolation and screening of potential actinobacteria for rapid composting of rice straw 总被引:2,自引:0,他引:2
Rice straw is produced as a by-product from rice cultivation, which is composed largely of lignocellulosic materials amenable
to general biodegradation. Lignocellulolytic actinobacteria can be used as a potential agent for rapid composting of bulky
rice straw. Twenty-five actinobacteria isolates were isolated from various in situ and in vitro rice straw compost sources.
Isolates A2, A4, A7, A9 and A24 were selected through enzymatic degradation of starch, cellulose and lignin followed by the
screening for their adaptability on rice straw powder amended media. The best adapted isolate (A7) was identified as Micromonospora
carbonacea. It was able to degrade cellulose, hemicelluloses and carbon significantly (P ≤ 0.05) over the control. C/N ratio was reduced to 18.1 from an initial value of 29.3 in 6 weeks of composting thus having
the potential to be used in large scale composting of rice straw. 相似文献
4.
Audesh Bhat Anil Koul Ekta Rai Swarkar Sharma M. K. Dhar R. N. K. Bamezai 《Human genetics》2008,123(1):115
5.
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Summary The rhizosphere microflora of arecanut palm under continuous application of organic manures and inorganic fertilizers was
studied. The nutrients applied are 100 g N, 40 g P2O5 and 140 g K2O/palm/year in the form of organics and inorganics. The application of organic manure increased the microbial population.
The increase in microbial population was observed between the rhizosphere samples collected at 0–30cm and 30–60 cm depths.
The surface cultivation of soil increased the microbial population.Trichoderma sp. andAspergillus sp. dominated in therhizosphere of arecanut palm.
Contribution No. 208. Central Plantation Crops Research Institute, Vittal-574243, Karnataka, India. 相似文献
7.
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Sporotrichum thermophile Growth, Cellulose Degradation, and Cellulase Activity 总被引:3,自引:1,他引:2 下载免费PDF全文
The activity of components of the extracellular cellulase system of the thermophilic fungus Sporotrichum thermophile showed appreciable differences between strains; β-glucosidase (EC 3.2.1.21) was the most variable component. Although its endoglucanase (EC 3.2.1.4) and exoglucanase (EC 3.2.1.91) activities were markedly lower, S. thermophile degraded cellulose faster than Trichoderma reesei. The production of β-glucosidase lagged behind that of endoglucanase and exoglucanase. The latter activities were produced during active growth. When growth was inhibited by cycloheximide treatment, the hydrolysis of cellulose was lower than in the control in spite of the presence of both endoglucanase and exoglucanase activities in the culture medium. Degradation of cellulose was a growth-associated process, with cellulase preparations hydrolyzing cellulose only to a limited extent. The growth rate and cell density of S. thermophile were similar in media containing cellulose or glucose. A distinctive feature of fungal development in media incorporating cellulose or lactose (inducers of cellulase activity) was the rapid differentiation of reproductive units and autolysis of hyphal cells to liberate propagules which were capable of renewing growth immediately. 相似文献
9.
Metabolism of all-trans-retinol and all-trans-retinoic acid in rabbit tracheal epithelial cells in culture 总被引:1,自引:0,他引:1
As reported previously squamous cell differentiation of rabbit tracheal epithelial (RTE) cells in culture is a multi-step process. This program of differentiation is inhibited by retinoic acid and retinol; retinoic acid is about 100 times more effective than retinol. To examine the metabolism of these agents in this in vitro model system, RTE cells were grown in the presence of all-trans-[3H]retinol or all-trans-[3H]retinoic acid and their metabolites analyzed by high-pressure liquid chromatography. RTE cells converted most of the retinol to retinyl esters, predominantly retinyl palmitate. A small fraction was metabolized to polar compounds, one of which coeluted with retinoic acid. After methylation this compound eluted as 13-cis-methyl retinoate and as all-trans-methyl retinoate. Conversion to 13-cis-retinol was also observed. All-trans-retinoic acid was rapidly taken up by RTE cells and converted to more polar (peak 1) and less polar (peak 3) metabolites. A proportion of all-trans-[3H]retinoic acid was metabolized to 13-cis-[3H]retinoic acid. These metabolic reactions appeared to be constitutive and were not induced by pretreatment with retinoic acid. The peak 1 metabolites were rapidly secreted into the medium whereas the peak 3 metabolites were retained by the cells and were not detected in the medium. Alkaline hydrolysis of the metabolites in peak 3 yielded retinoic acid, indicating the formation of retinoyl derivatives. Our results establish that RTE cells can convert all-trans-retinol to 13-cis-retinol and retinoic acid. RTE can metabolize all-trans-retinoic acid to 13-cis-retinoic acid and to an unidentified ester of retinoic acid. 相似文献
10.
Effects of tissue position (viz. outer vs inner mesocarp) and heat treatment (48°C, 20 min) on variations in polygalacturonase (EC 3.2.1.15 and EC 3.2.1.67) activity and ripening of fruits of Carica papaya L. cv. Backcross Solo were investigated. Polygalacturonase activity increased during ripening concomitantly with an increase in tissue softness and soluble polyuronide level. Throughout ripening, inner mesocarp tissue was softer and contained higher polygalacturonase activity than outer mesocarp tissue. Titratable acidity as well as ß-galactosidase (EC 3.2.1.23) activity also increased during ripening; however, unlike polygalacturonase, their level or activity was lower in inner than in outer mesocarp. Ascorbic acid could partially account for the increase in titratable acidity during ripening but contributed very little to the differences in titratable acid levels between outer and inner mesocarp. Heat treatment had no effect on either fruit softness or titratable acidity, but it markedly reduced the increase in ascorbic acid and polygalacturonase activity during ripening. Ripening, as reflected by changes in tissue softness and polygalacturonase activity, progressed outwardly from the interior towards the exterior of the fruit. The effect of heat treatment in suppressing polygalacturonase activity was relatively greater in inner than in outer mesocarp, suggesting that sensitivity of the enzyme to heat treatment may vary with stage of ripeness of the tissue. 相似文献