黄瓜游离小孢子培养诱导成胚和植株再生   总被引：4，自引：0，他引：4  

詹艳  陈劲枫 《园艺学报》2009,36(2):221-226

 以10个不同基因型黄瓜为试材进行游离小孢子培养，通过对成胚条件的系统研究，从‘7447’和‘Poinsett97’中获得了子叶形胚和再生植株。研究结果表明：基因型和小孢子发育时期是限制黄瓜游离小孢子成胚的关键因子。不同品种间胚状体产量差异显著，每皿产胚1.5～33.4个。单核靠边期是进行黄瓜游离小孢子培养的最佳时期。低温预处理有利于胚状体的诱导，4 ℃预处理2～4 d为宜，以处理2 d时胚状体产量最高。外源激素在诱导胚状体时并非必需，但低浓度的外源激素（0.5 mg·L^-1 2,4－D、0.2 mg·L^-1 6－BA）更能促进小孢子成胚。NLN和B5两种基础培养基在诱导胚状体上无显著差异。子叶形胚易分化成苗，而其它类型的胚状体不能获得再生植株。  相似文献   

Effects of Stocking Density and Monosex Culture of Freshwater Prawn Macrobrachium rosenbergii on Growth and Production in Concrete Tanks in Saudi Arabia     

Abdul Qayyum  Siddiqui  Yousef S.  Al-Hafedh  Ahmed H.  Al-Harbi Seikh A.  Ali 《Journal of the World Aquaculture Society》1997,28(1):106-112

Abstract This study was conducted to evaluate the effects of stocking density and monosex culture on growth, survival, yield and feed conversion ratio of freshwater prawn Macrobrachium rosenbergii in concrete tanks. Juvenile prawns with an average weight of 1.8 g were stocked into triplicate tanks at densities of 5, 10, 15 and 20 prawns/m², grown for 168 d and fed a 34% tilapia diet. Stocking density had significant effect on prawns. Final mean body weight decreased with the increasing density, being highest at 5 prawns/m² (29.6 9). and lowest at 20 prawns/m² (17.4 g). Total yield increased from 135 g/m² (1,350 kg/ha) at a density of 5 prawns/m² to 261 g/m² (2,610 kg/ha) at density 15/m^z to 245 g/m² (2,450 kg/ha) at 20/m^z. Feed conversion ratios were high and ranged from 3.7 (5 prawns/m²) to 5.6 (20 prawns/m²).
In monosex culture of freshwater prawns stocked in triplicate tanks at a density of 5 prawns/m² for 112 d, the all-male population had the best growth performance and feed conversion ratio, followed by the mixed-sex and all-female populations. The all-male population had 99% marketable prawns (>20 g) with an average yield of 159 g/m² (1,590 kg/ha); the mixed-sex population had 90% marketable prawns and the yield was 135 g/m^z (1,350 kg/ha); and the all-female population had 75% marketable prawns with an average yield of 108 g/m² (1,080 kgha).  相似文献   

Ultrastructure of Camel (Camelus dromedarius) Spermatozoa     

E. Heath    M. S. Mostafa  S. Karasek 《Anatomia, histologia, embryologia》1986,15(2):147-154

Spermatozoa collected from the caudae epididymidis of six camels were examined by phase contrast, scanning electron and transmission electron microscopy. A comparison of the morphology of the camel spermatozoa with that of other domestic animals is presented.  相似文献   

Effects of emulsified versus saline administration of GnRHa on induction of ovulation in rainbow trout, Oncorhynchus mykiss     

Arya Vazirzadeh  Abdolmajid Hajimoradloo  Hamid Reza Esmaeili  Mostafa Akhlaghi 《Aquaculture (Amsterdam, Netherlands)》2008,280(1-4):267-269

The effects of saline-dissolved or Freund's incomplete adjuvant (FIA)-emulsified GnRHa treatment on the induction of ovulation in rainbow trout, Oncorhynchus mykiss, were examined. The FIA-emulsified GnRHa was first diluted in 0.25 ml physiological saline and then mixed with an equal volume of FIA. Fish were selected in the beginning of the spawning season and were allocated into four groups and were treated intraperitoneally with (a) 0.5 ml of emulsified GnRHa (GnRHa–FIA), (b) 0.5 ml saline-dissolved GnRHa in a single injection (GnRHa-1), (c) 0.5 ml saline-dissolved GnRHa in two injections spaced 1 d apart (GnRHa-2) and (d) 0.5 ml of saline (Control). The GnRHa dose in all hormone treatments was 25 µg kg^− 1. All fish in the FIA–GnRHa and GnRHa-2 groups ovulated within 10 and 11 d after treatment, respectively. In contrast, only 75% in the Control fish and 60% of the fish in the GnRHa-1 group ovulated within 36 d after treatment. None of the treatments caused any pre- or post-spawning mortality in the broodstock. Fertilization, eyeing and hatching percentages of the produced progeny were normal in all the treatment groups and did not differ significantly among them. In conclusion, FIA-emulsified GnRHa can be effective in advancing the onset of and synchronizing the ovulation of rainbow trout within a two-week period, thus shortening the egg collection period, without affecting broodstock survival and egg quality.  相似文献   

Explosion pulping of eucalyptus: a comparison with CTMP and CMP     

B. V. Kokta  A. Ahmed 《Wood Science and Technology》1993,27(4):271-279

Summary Explosion pulping results in strong pulp with breaking length at 100 ml CSF (Canadian standard freeness) higher than 6.5 kg and burst index approaching 4 KPa m²/g. The real advantage of eucalyptus explosion pulp over conventional CMP (chemical-mechanical pulp) and CTMP (chemical-thermo-mechanical pulp) is observed when the impregnation solution contains less than 2% NaOH along with 8% Na₂SO₃, and when the liquor/chips ratio equals 3. The strength of eucalyptus explosion pulp obtained by using a pretreatment solution consisting of 8% Na₂SO₃ and 1% NaOH is comparable with that of eucalyptus kraft pulp. The concentration of NaOH present in the pretreatment solution has a very important effect on the specific refining energy of eucalyptus explosion pulp as well as of CMP and CTMP. The explosion pulp obtained from eucalyptus pretreated with a solution containing an appropriate quantity of caustic along with Na₂SO₃ not only requires a minimum specific refining energy but also provides the highest strength values in comparison to that of CMP and CTMP.  相似文献   

Agroforestry: a viable land use of alkali soils     

P. Ahmed 《Agroforestry Systems》1991,14(1):23-37

A system of land use of alkaline wastelands of the Indo-Gangetic plain has been proposed consisting of planting Prosopis juliflora, a multi-purpose tree species, with the objectives of economic return as well as soil amelioration. Tree farming onalkaline wastelands provides not only fuel, fodder, timber and income to the rural population but also shows good effects in improving the soil characteristics. The detailed costs of such an agroforestry system on alkali soils have been worked out and the mean annual production of Prosopis juliflora on soils of different pH have been analysed. In spite of the high cost of establishing a plantation, an economic analysis of the system yields a 9.5% internal rate of return which is reasonably high for degraded lands of strongly alkali soils and also viable within the economic structure of the region.  相似文献   

Bioactive constituents of Leptadenia arborea     

El-Hassan A  El-Sayed M  Hamed AI  Rhee IK  Ahmed AA  Zeller KP  Verpoorte R 《Fitoterapia》2003,74(1-2):184-187

The aerial part of Leptadenia arborea has been shown to contain pinoresinol (1), syringaresinol (2), leucanthemitol (3) and E-ferulaldehyde (4). These known compounds are being reported for the first time from this plant. Among them, syringaresinol has shown an inhibitory effect against acetylcholinesterase. The IC(50) (the concentration of 50% enzyme inhibition) value of this compound was 200 microg/ml.  相似文献   

A new eudesmanolide from Crataegus flava fruits.     

A A Ahmed  A M Khattab  M H Grace  M M Sahl 《Fitoterapia》2001,72(7):756-759

A new eudesmanolide, 1beta,9alpha-dihydroxyeudesm-3-en-5beta,6alpha,7alpha,11alphaH-12,6-olide (1), was isolated from Crataegus flava fruits. Its structure was determined by spectroscopic methods.  相似文献   

Resistant Starch Content Is Related to Granule Size in Barley     

Zaheer Ahmed  Ian J. Tetlow  Duane E. Falk  Qiang Liu  Michael J. Emes 《Cereal Chemistry》2016,93(6):618-630

Physical properties of resistant starch (RS) were examined in a range of barley genotypes to determine the contribution of starch and seed physical characteristics to the RS component. Thirty‐three barley genotypes were studied, which varied significantly in their RS, amylose, and starch contents and grain yield. From 33 genotypes, 13 exhibiting high RS were selected for detailed physicochemical analysis of starch. In high‐RS varieties, granule size and number were unimodal, compared with normal starches from a reference genotype, which showed a bimodal distribution. Principal component analysis (PCA) showed that a higher content of granules <15 µm was positively correlated with RS and amylose content, whereas the proportion of granules 15–45 µm was negatively correlated with the RS and amylose contents. Physical fractionation of starches by centrifugation into different population sizes demonstrated that size alone is not an accurate indicator of the population of A‐type and B‐type granules within a given genotype. PCA also showed that large 15–45 µm granules were positively correlated with seed thickness and that thousand grain weight was positively correlated with seed width. High‐RS and high‐amylose genotypes showed variation in overall yield and starch content, with some genotypes showing yield comparable to the reference genotype. Analysis of amylopectin chain length distribution showed that high amylose or RS content was not associated with a higher proportion of amylopectin long chains when compared with either waxy or reference (normal) barley genotypes. This study highlights useful markers for screening barley genotypes with favorable starch characteristics.  相似文献   

Labor- und Freilandversuche zur Bekämpfung von vier Blattlausarten mit zwei synthetischen Juvenilhormon-Analogen     

Associate Professors S. M. Ahmed  Associate Professors A. A. Abdel-Gawaad 《Journal of pest science》1975,48(10):148-150

Laboratory and field trials with two synthetic Juvenil Hormone Analogues on four Aphid species Two juvenile hormone analogues (JHA) were applied in laboratory in three different concentrations to four aphid species. Mortality-concentrations and mortality-time for the lowest concentration were plotted on logprobit paper and the slope calculated from the eye fitted lines. The results indicated the feasibility of probit analysis for concentration-mortality or time mortality responses. However in one of the aphid species i. e.Aphis gossypii, there was a lack of linearity in the relationship, this species proved to be tolerant to JHA in field trials. Both JHA supressed progeny production, the supression was found to be selective to different species. In field trials both JHA brought about appreciable reductions in the populations with the exception ofAphis gossypii. The colour ofH. arundinis was found to differ in adults insuing from treated nymphs, otherwise no remarkable morphonogenic changes were observed.  相似文献