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11.
【目的】进一步探明盐胁迫条件下营养元素K+、Ca2+和Mg2+对苗期不同水稻基因型耐盐性的影响差异,为明确作物耐盐胁迫的生理机制、提高作物耐盐胁迫能力提供参考。【方法】于2009年1—4月在严格控制水、温、光和营养元素供应的国际水稻研究所人工气候室进行水培试验,比较研究营养液中K+、Ca2+和Mg2+浓度的变化对不同水稻基因型苗期耐盐性的影响。【结果】在盐胁迫条件下(100mmol·L-1NaCl),耐盐基因型(FL478和IR651)与盐敏感基因型(IR29和Azucena)相比,植株体内有较低的Na+含量和Na+/K+、Na+/Ca2+、Na+/Mg2+比,有较高的K+含量,这些都是耐盐基因型耐盐胁迫能力高于盐敏感基因型的内在原因。盐胁迫条件下提高营养液中Ca2+和Mg2+的含量(60mg·L-1),可显著降低植株体Na+含量和Na+/K+、Na+/Ca2+、Na+/Mg2+比,明显减轻盐胁迫的危害,增强水稻耐盐胁迫能力,且Ca2+处理的效果优于Mg2+处理;而提高营养液K+含量对以上指标的影响远远小于Ca2+处理和Mg2+处理,这也是K+处理对水稻耐盐性影响相对不明显的内在原因。【结论】K+、Ca2+和Mg2+在植株体内的含量及其与Na+的比值变化都会影响水稻苗期耐盐性;适当提高水稻生长环境的Ca2+和Mg2+浓度可以明显增强植株耐盐胁迫能力,营养元素Ca2+的效果比Mg2+明显;而K+对水稻耐盐性的影响相对不明显。 相似文献
12.
The metabolism, uptake and translocation of paraquat in resistant (R) and susceptible (S) biotypes of Crassocephalum crepidioides (Benth.) S. Moore (redflower ragleaf) at the 10-leaf stage was investigated. A study on the properties of leaf surface was carried out to examine the relationship between leaf surface characters and paraquat absorption. The extractable paraquat was not metabolized by the leaf tissue of either the resistant or susceptible biotypes. Differential metabolism, therefore, does not appear to play a role in the mechanism of resistance. Both biotypes did not show any significant difference in the amount of cuticle and trichome densities. Furthermore, both biotypes are identical in the structure of stomata, trichomes and epicuticular wax. The results of the leaf surface studies are in agreement with the findings of the uptake study. Both biotypes demonstrated no significant difference in absorption between the resistant and susceptible biotypes. However, 10% of the absorbed 14 C-paraquat into the S biotype was translocated basipetally, but not in the R biotype. The results of this study suggest that in C. crepidioides , differential translocation may contribute to the mechanism of resistance at the 10-leaf stage. 相似文献
13.
Twenty two summer weeds belonging to fifteen plant families and twelve winter weeds from eight plant families were tested to compare the effects of their root diffusates with the corn root diffusates (CRD) of cv. Giza 2 on the hatchability of the corn cyst nematode (CCN),Heterodera zeae.All tested weed root diffusates (WRD) successfully stimulated the hatchability of the cysts, but less than CRD did except the root diffusates (RD) ofRumex dentatus which failed to stimulate the nematode cysts. 相似文献
14.
Bluetongue virus type 16, isolated from sheep in Egypt, was injected to 4 normally cycling Barki ewes and caused high levels of inhibin. This was assayed by a biological method, using suppression of the luteinising hormone (LH) of castrated rats. Albumin (fraction 2) was injected to normally cycling ewes. The sera of injected ewes were investigated 1 day after injection and weekly up to the 4th one injection. There was a gradual decrease of LH (4.8 +/- 0.52 I.U./ml serum) until the minimum level (1.17 +/- 0.25 I.U./ml serum) was reached, in comparison to the control serum LH which was 5.26 +/- 0.52 I.U./ml serum during the dioestrous phase. 相似文献
15.
The aim of this study was to investigate the effects of two commercially available probiotics, alone and in combination with an antibiotic, on the caecal flora of Japanese quail (Coturnix coturnix japonica) reared under unstressed conditions. Thirty-four 90-day-old Japanese quail were selected for this study. The birds were divided into four groups, two groups of nine birds and two groups of eight birds. The animals in these groups were given feed containing 0.5 kg per tonne of probiotics alone (Protexin or Biosacc), a mixture of probiotic plus antibiotic (Biosacc plus Zinc Bacitracin at 0.5 and 0.0525 ppm, respectively), and a group where no supplement was added to be used as controls. The total count of aerobic bacteria, lactobacilli, enterobacteriaceae, coliforms, enteroccoci, salmonellae, sulphite-reducing anaerobic bacteria (clostridia), and pH values in the caecal content of the birds were examined. No significant differences were detected among the four groups for pH values and bacterial number (p>0.05), except for sulphite-reducing anaerobic bacteria (p<0.001). These results suggest that the use of probiotics alone and/or a mixture of a probiotic plus antibiotic as a feed supplement does not have a major suppressing effect on the majority of bacterial groups in the caecal flora of mature, healthy Japanese quail reared in unstressed conditions. 相似文献
16.
A. E. Ismail 《Anzeiger für Sch?dlingskunde》1998,71(7):138-141
Four hardwood barks (HWB) i. e.Acacia arabica (AA),Ficus sycomorus (FS),Morus alba (MA) andZiziphus spinachristi (ZS) were tried as soil amendments at 0.5, 1.0 and 1.5% rates w/w for control ofRotylenchulus reniformis and improvement of cv. Giza 1 sunflower growth under greenhouse conditions. All HWB with various concentrations significantly
(P≤0.01) reduced numbers of larvae in soil, both females and eggmasses on roots, total final nematode population as well as
the nematode build-up as compared to control. 1.5% rate of ZS, AA and MA barks were most effective in reducing numbers of
larvae in soil, total final nematode population and the nematode build-up. Also, 1.5% rate of each of FS and AA barks were
most effective in reducing numbers of females or eggmasses, respectively. On the other hand, the least reduction in the previous
nematode stages and rate of build-up was observed with 0.5% dose of FS bark. Shoot weights were increased significantly with
both of 1.0% and 1.5% doses of each of FS and ZS barks and only with 1.5% dose of MA bark. Both shoot lengths and root weights
increased significantly with 1.5% dose of all HWB or with 1.0% dose of each of AA and ZS barks as compared to control. No
significant increase in root lengths was observed. Generally, there were positive significant correlations between doses of
HWB, each of the reductions in the previous nematode stages and increases in sunflower growth criteria. 相似文献
17.
Effendy A.W.M. Zamri-Saad M. Maswati M.A. Ismail M.S. Jamil S.M. 《Veterinary research communications》1998,22(3):147-153
Twenty goats of about 7 months of age were divided into five groups. The goats in groups 1 and 2 were exposed once, using an intranasal spray to 2 ml of an inoculum containing 106 colony-forming units/ml of living or dead Pasteurella haemolytica A2, respectively. The goats in groups 3 and 4 were similarly exposed twice at a 2-week interval. Group 5 was the untreated control. The number and size of the bronchus-associated lymphoid tissue (BALT) in goats exposed twice to either living or dead organisms were significantly (p>0.05) increased compared with those exposed once and with the unexposed control. In vitro colonization by living P. haemolytica A2 onto the lung tissue in which the BALT had been stimulated by two exposures of either living or dead organisms was significantly (p>0.05) reduced. The study indicates that stimulation of the respiratory mucosal immunity may prevent P. haemolytica A2 infection. 相似文献
18.
I M Ismail F Mohamed N M Aly N M Allam H B Hassan M S Saber 《Archiv fuer experimentelle veterinaermedizin》1990,44(5):789-792
2 Egyptian goats and Boscat rabbits were experimentally inoculated with peste des petits ruminants (PPR) local Egyptian strain (PPR, Egypt 87). The inoculated animals contracted the disease with minor clinical manifestations, accompanied by rise of neutralizing antibodies to PPR virus. Virus was isolated from ocular and nasal secretions, buffy coat, spleen, and liver. No contact infection was observed between inoculated and healthy goats. 相似文献
19.
Peste des petits ruminants virus was isolated from young goats in an outbreak of the disease for the first time in Egypt. Affected goats showed symptoms simulating rinderpest, disease in cattle. The mortality rate was about 30%, and morbidity reached 90%. History, clinical symptoms, postmortem lesions, and diagnosis were discussed. 相似文献
20.
Vaidya NA Mathias K Ismail B Hayes KD Corvalan CM 《Journal of agricultural and food chemistry》2007,55(9):3408-3413
The conversion and degradation of malonylglucosides were kinetically characterized under elevated pH/heat conditions. Malonylgenistin and malonyldaidzin were heated at 60, 80, and 100 degrees C and pH values of 8.5, 9, and 9.5. A simple kinetic model was developed, which adequately predicted the conversion and degradation reactions. The conversion and degradation rates increased as temperature and pH increased. The rates of conversion of both malonylglucosides into their respective beta-glucosides were comparable under all pH/heat treatments. However, at 100 degrees C, the rates of degradation of malonyldaidzin were approximately double those of malonylgenistin, under all pH treatments. When malonlydaidzin was heated at 100 degrees C and pH 9.5, degradation of the produced daidzin occurred. Therefore, an alternative kinetic model was developed to better predict the conversion and degradation of malonyldaidzin occurring at 100 degrees C and pH 9.5. The models developed provide soy food manufacturers with guidelines for better control of the profile and level of isoflavones.. 相似文献