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排序方式: 共有333条查询结果,搜索用时 15 毫秒
11.
Bobe G Wang B Seeram NP Nair MG Bourquin LD 《Journal of agricultural and food chemistry》2006,54(25):9322-9328
A promising approach for cancer chemoprevention might be a combination therapy utilizing dietary phytochemicals and anticarcinogenic pharmaceuticals at a suboptimal dosage to minimize any potential adverse side effects. To test this hypothesis, various dosages of anthocyanin-rich tart cherry extract were fed in combination with suboptimal levels of the nonsteroidal anti-inflammatory drug sulindac to APCMin mice for 19 weeks. By the end of the feeding period, fewer mice that were fed the anthocyanin-rich extract in combination with sulindac lost more than 10% of body weight than mice fed sulindac alone. Mice that were fed anthocyanin-rich extract (at any dose) in combination with sulindac had fewer tumors and a smaller total tumor burden (total tumor area per mouse) in the small intestine when compared to mice fed sulindac alone. These results suggest that a dietary combination of tart cherry anthocyanins and sulindac is more protective against colon cancer than sulindac alone. 相似文献
12.
Insecticidal fatty acids and triglycerides from Dirca palustris. 总被引:3,自引:0,他引:3
R S Ramsewak M G Nair S Murugesan W J Mattson J Zasada 《Journal of agricultural and food chemistry》2001,49(12):5852-5856
Five compounds, 1-5, were isolated from the seed hexane extract of Dirca palustris. Compounds 1-3 were triglycerides, and 4 and 5 were linoleic and oleic acids, respectively. Compounds 1-3 were not biologically active; however, 4 (linoleic acid) and 5 (oleic acid) were insecticidal against fourth instar Aedes aegyptii larvae and exhibited potent feeding deterrent activity against neonate larvae of Helicoverpa zea, Lymantria dispar, Orgyia leucostigma, and Malacosoma disstria. 相似文献
13.
Samuel C. Allen Shibu Jose P. K. R. Nair Barry J. Brecke Vimala D. Nair Donald A. Graetz Craig L. Ramsey 《Biology and Fertility of Soils》2005,41(1):28-37
Information on temporal and spatial patterns of N mineralization is critical in designing tree-crop mixed systems that could maximize N uptake while minimizing N loss. We quantified N mineralization rates in a pecan (Carya illinoensis K. Koch)–cotton (Gossypium hirsutum L.) alley cropping system in northwestern Florida with (non-barrier) and without tree-crop belowground interactions (barrier separating the root systems of pecan and cotton). Monthly rates of mineralization were estimated using buried bag incubations over a 15-month period. In addition, seasonal mineralization rates and cotton lint yield on soils supplied with two sources of N—inorganic fertilizer and organic poultry litter—were assessed. Results indicated that temporal variations in net NH4 and NO3 accumulation and mineralization rates were driven primarily by environmental factors and to a lesser degree by initial soil NH4 and NO3 levels. Mineralization varied by belowground interaction treatment during the initial growing season, when the non-barrier treatment exhibited a higher mineralization rate than the barrier treatment, likely due to reduced nutrient uptake by cotton in the non-barrier or a higher degree of immobilization in the barrier treatment. Mineralization during the second growing season was similar for both treatments. Source of N had no effects on N transformation in the soil. Lint yield reductions were observed in the non-barrier treatment during both years compared to the barrier treatment, likely due to interspecific competition for water. Yield differences between treatments in the second growing season were likely compounded by a diminishing pre-study fallow effect. Source of N was found to have a significant effect on cotton yield, with inorganic fertilizer resulting in 39% higher lint compared to poultry litter in the barrier treatment. 相似文献
14.
Genotypic variation and mycorrhiza play an important role in plant uptake of phosphorus (P). A pot experiment was conducted with three cereals, wheat (Triticum aestivum L. cv. PBW-34), rye (Secale cereale L. cv. R-308), and triticale (Triticale octoploide L. cv. DT-46), a hybrid of wheat and rye, to examine the genetic variation in the degree of arbuscular-mycorrhizal (AM) infection and its inheritability from parents (wheat and rye) to their progeny (triticale). The soil used for pot culture was low in available P (7.8 mg P kg?1soil). Inoculation with AM fungi showed a significant increase in extent of root colonization for all three cereals (average 70%) compared with their performance without AM (average 19.1%). However, among the three cereals, this increase was significantly greater in rye than in the other two crops, while wheat and triticale did not differ significantly. Mycorrhizal infection resulted in 1.6, 1.7, and 1.8-fold increases in shoot, root, and total plant dry matter, respectively, compared with the un-inoculated treatment. Among the three cereals, rye recorded maximum shoot, root, and total plant dry mass and P content with AM inoculation. The P uptake by wheat, rye, and triticale was 10%, 64%, and 35%, respectively, higher with rather than without mycorrhizal infection. Rye was most responsive to AM inoculation, with mycorrhizal dependency of 193%; here again, triticale followed wheat, with similar mycorrhizal dependency. Rye showed an increase in P utilization efficiency (PUE) without AM inoculation while the PUE of triticale was intermediate between wheat and rye. High efficiency of AM symbiosis in terms of P uptake exists in rye and most of these traits in triticale seem to be inherited from wheat rather than rye. 相似文献
15.
Summary A high degree of fruit and seed set was obtained in Dioscorea alata L. by hand pollination. The sexual progeny was studied in comparison with the clonal plants. In general, the seedlings were poor in growth vigour, flowering and tuber production but the variations observed in the different characters were unprecedented, indicating scope for efficacious genetic improvement in this vegetatively propagated crop. 相似文献
16.
17.
A study was conducted in northwest Florida, USA, to investigate root development and morphology of cotton (Gossypium hirsutum L.) under pecan (Carya illinoensis K. Koch) trees in an alleycropping experiment. Root:shoot ratio, root biomass, total root length and root length density
were examined under three treatments: (1) barrier (separating belowground interspecific competition by trenching to a depth
of 120 cm and installing polyethylene barrier), (2) non-barrier (root systems were free to interact), and (3) monoculture
of cotton (without above and belowground interspecific competition with trees). Results indicated that plants in the barrier
and non-barrier treatments had lower root:shoot ratios compared to the monoculture treatment. Belowground competition for
resources between pecan and cotton in the non-barrier treatment resulted in 25 and 33% reduction of total root length (359 cm)
when compared to that of the barrier (477 cm) and monoculture (539 cm) treatments, respectively. The non-barrier plants also
exhibited the lowest root length density. Specific root length was highest for the monoculture (179 cm g−1) and lowest for the non-barrier treatment (146 cm g−1) with the barrier treatment being intermediate (165 cm g−1). Interspecific competition with pecan significantly altered root development and morphology of cotton plants. Research in
agroforestry should take into account the developmental differences in root systems of the associated crop species so that
better models incorporating nutrient and water uptake can be developed. 相似文献
18.
Herrera MR Machocho AK Nair JJ Campbell WE Brun R Viladomat F Codina C Bastida J 《Fitoterapia》2001,72(4):444-448
The alcoholic extract of the fresh bulbs of Cyrtanthus elatus yielded zephyranthine (1) and 1,2-O-diacetylzephyranthine (2), together with three other known alkaloids. Complete assignment of 1H and 13C NMR spectra of compounds 1 and 2 was done by employment of two-dimensional NMR techniques. 相似文献
19.
20.
Sherin George P. R. Suresh P. A. Wahid Ramesh B. Nair K. I. Punnoose 《Agroforestry Systems》2009,76(2):275-281
The active root distribution pattern of mature rubber (Hevea brasiliensis Muell. Arg.) up to a lateral distance of 250 cm from the tree and to a soil depth of 90 cm was studied in an oxisol by employing
32P soil injection technique in Kerala, the state which accounts for 83% of rubber cultivation in India. The trees were aged
18 years and grown at a spacing of 4.9 × 4.9 m. The extent of absorption of applied 32P by the tree from various placements was assessed by radio assay of leaf and latex serum. Latex serum registered higher counts
and variability was less compared to leaf indicating the suitability of latex serum as a potential source for radio assay
for 32P studies in rubber. The results revealed that rubber is a surface feeder with 55% of the root activity confining to the top
10 cm of soil layer. Root activity declined with increasing depths and the concentration of physiologically active roots at
90 cm depth was only 6%. A more or less uniform distribution of root activity was noticed with respect to lateral distance
indicating more extensive spread of lateral roots. Concentration of physiologically active roots in the surface layer suggests
the possibility for competition under intercropped situation in mature plantations. 相似文献