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991.
For improving seed germination of Prosopis koelziana and Prosopis juliflora, different treatments of seeds were conducted, including scarification with sulfuric acid 98% for 10 and 15 min, sandy paper, hot water for 5 and 10 min, potasium nitrate 0.1%, gibberellic acid at 250 mg·L−1 and 500 mg·L−1 and combinational treatment of scarification with gibberellic acid of 250 mg·L−1 and 500 mg·L−1. The results show that scarifications with sandy paper and sulfuric acids 98% were the most effective treatments on breaking seed dormancy and seed germination induction. Scarification with sulfuric acid 98% for 15 min was the best treatment. According to the positive effect of scarification and lack of reaction of seeds against KNO3 and gibberellic acid, the kind of seed dormancy was determined as exogenous.  相似文献   
992.
In this study we investigated the rooting ability and the growth performance of juvenile single-node leafy stem cuttings of Litsea monopetala (Roxb) Pers. collected from two mature mother trees preserved in the hill forest of Chittagong district, Bangladesh. The rooting ability of cuttings was studied under 0%, 0.1%, 0.2% and 0.4% indole-3-butyric acid (IBA) treatments. Significantly better rooting response (p ≤ 0.05) was observed with 0.1% IBA compared to control (0% IBA). The mean number of roots and the length of the longest root of cuttings in different treatments showed no significant difference (p≤0.05). After transfer into polythene bags from non-mist propagator, rooted cuttings treated with 0%, 0.1% and 0.2% IBA demonstrated the highest (100 ± 0.00%) survival capacity. The mean number of shoots developed in cuttings in the polythene bags in first three weeks varied significantly (p≤0.05) among the treatments. Effects of three fertilizer treatments, viz. T0 (no fertilizer), T1 (10g Urea, 20g TSP, 10g MOP dissolved in 1 L water) and T2 (10g Urea, 20g TSP, 10g MOP dissolved in 2 L water) on initial growth ofstecklings were also measured over a 90-days period. The increment of leaf area of stecklings was significantly higher (p≤0.05) under T0 compared with that under T1 and T2 while the increment of stem length, collar diameter and root biomass varied insignificantly among different fertilizer treatments. The results suggest that rooting juvenile single-node leafy stem cuttings could be an effective mean of regenerating L. monopetala. The application of 0.1% IBA concentration is recommended for rooting of juvenile leafy stem cuttings and application of fertilizer appeared unnecessary for the subsequent growth of stecklings in polythene bags.  相似文献   
993.
Synthetic seed has become a proficient tool that facilitates conservation as well as mass propagation of elite plant species by encapsulating somatic embryo or meristem tissue. Inclusion of meristematic tissues instead of somatic embryos hastens widespread utilization of this technology in recent years. Synseeds offer short term conservation of germplasms, provide readily available tissue source for easy mass propagation where each synseeds can virtually act as zygotic seeds giving rise to plantlets. This is the first report on synseed production following the confirmation of the genetic homogeneity in regenerated plantlets of Balanites aegyptiaca Del. (L.) using ISSR marker system. In this study, nodal segments, excised from in vitro proliferated shoot cultures developed from mother plant, were encapsulated in calcium alginate beads and the finest gel complexation was achieved using 3 % sodium alginate and 100 mM CaCl2·2H2O. Maximum percent response (80 %) for conversion of encapsulated nodal segments into plantlets was obtained on Murashige and Skoog (MS) medium containing 12.5 μM benzyladenine and 1.0 μM α-naphthalene acetic acid. Encapsulated nodal segments could be stored at low temperature (4 °C) up to 4 weeks with a survival frequency of 82 %. The regenerated shoots were rooted on half strength MS medium augmented with 1.0 μM indole-3-butyric acid. Well-developed plantlets regenerated from encapsulated nodal segments were acclimatized successfully with 90 % survival frequency. Fingerprinting profiles of the regenerated plantlets derived from synseeds and the donor plant were generated using a total of 20 ISSR primers, of which 14 primers produced distinct, reproducible amplified products. A total of 158 scorable bands were obtained from the complete amalgamation of primers and plantlets and 98.7 % bands were monomorphic across the plantlets which indicate that this micropropagated line derived from synseed is genetically stable and demonstrates the reliability of our protocol for short term conservation, germplasm exchange and distribution of identical plants.  相似文献   
994.
We investigated the effect of seed mass on emergence, seedling survival and growth ofPterocarpus marsupium Roxb., a medium to large, commercially valuable and deciduous tree species. Among the three size classes viz. small (10-12 mm), medium (13-15 mm) and large (16-17 mm), the maximum proportion, of seed by number (54.12%) and dry weight (51.87%) was recorded, in the medium size seed class. Seed length and seed width were greatest in the large seed class (16.50 mm, 7.33 mm) followed by medium (13.50 mm, 5.60 mm) and small (11.37 ram, 3.66 mm). Similarly, hundred seed weight (100 sw) varied from a maximum of 12.92 g in the large seed class to intermediate 10.95 g in the medium seed class and minimum of 7.02 g in the small seed class. The large seed size showed maximum emergence and shoot length over the medium and small seed class. After six months of growth, significant variations due to seed size were also observed for the growth and dry weight of P. marsupium seedlings. Seedling vigour, expressed in terms of height, collar diameter, number of leaves and dry biomass, was sig- nificantly affected by seed class. Seedlings that emerged from large seeds showed better growth and produced heavier seedlings as compared to medium and small seeds.  相似文献   
995.
996.
Determination of the sex and gonadal maturity of fish is necessary for successful commercial aquaculture operations. Sex identification is problematic in grouper fish, because they change sex at certain ages or sizes. Here we represent an accurate and reliable method for sex determination of the live grouper, using 5–10 mg gonadal tissue samples, harvested using non-lethal gonadal biopsy. Sex and sexual maturity of biopsied individuals were determined using standard histological method. All biopsied fish survived and there were no serious infections resulting from the surgery. Therefore, this biopsy technique is a simple and cost-effective tool for grouper fishery management.  相似文献   
997.
Journal of Crop Science and Biotechnology - The role of genetic diversity in crop germplasm is an important concept within genetic conservation. In this research, 43 accessions were analyzed at the...  相似文献   
998.
Linseed (Linum usitatissimum L.) is an important dual-purpose, industrial crop. Its seeds are used for the extraction of oil and stem for fibres. However, the production of linseed is not going parallel with the increasing demand of its products. The present work was carried out with an aim to find out whether exogenous application of gibberellic acid (GA3) with or without graded levels of nitrogen (N) and phosphorus (P) could improve the performance of three linseed genotypes Parvati, Shekhar and Shubhra together with minimizing the costly fertilizer input and losses. Four combinations of N and P, viz., 0 mg N+0 mg P kg-1 soil (N0P0), N13.4 P4.46 , N26.8P8.94 and N40.2P13.4 were constituted. Half dose of each combination was applied basally at the time of sowing and remaining half dose was given at 40 d after sowing (DAS) as foliar spray along with 10-6 mol L-1 GA3 . Prior to sowing, the seeds of each linseed genotype were grouped in to two, one group of seeds was soaked in 0 mol L-1 GA3 (control) and the other group was soaked in 10-6 M GA3 solution, each for 8 hours. Treatments were comprised of (i) 0 mol L-1 GA3+N0P0 (T0 , control), (ii) 10-6 mol L-1 GA3 + N13.4P4.46 (T1), (iii) 10-6 mol L-1 GA 3 +N 26.8 P 8.94 (T2) and (iv) 10-6 mol L-1 GA3+N40.2P13.4 (T3). The crop performance was assessed in terms of growth, physiological and biochemical parameters at 60 and 75 DAS and yield attributes at harvest (175 DAS). The results showed a parallel increase in most of the parameters with increasing levels of N and P. However, application of 10-6 mol L-1 GA3 in association with N26.8P8.94 proved best, it enhanced seed yield, oil yield and fibre yield by 83.3, 97.3 and 78.7%, respectively accompanied with increase in net photosynthetic rate, carbonic anhydrase activity and dry matter accumulation. Among the genotypes tested, Shubhra performed best, while Parvati the least for most of the parameters studied. Thus, combined application of 10-6 mol L-1 GA3 plus N26.8P8.94 proved best and can be recommended to exploit the linseed as a dual-purpose crop for good yield of seed and fibre.  相似文献   
999.
Chloroform extract (CE) of Achyranthes ferruginea and N-trans-feruloyl-4-methyldopamine (1) showed remarkable antimicrobial activities against a wide range of bacteria and fungi. Both crude extract (CE) and compound 1 showed significant cytotoxicity of LC(50) at 16.21 microg/ml and 11.70 microg/ml, respectively.  相似文献   
1000.
The major pathogens causing mastitis were evaluated by multiplex-polymerase chain reaction (M-PCR) with self-designed primers in four quarters of the first, third, and fifth parities in industrial, semi-industrial, and traditional dairy cattle farms in Iran. With the incidence of infection in the quarters by Staphylococcus aureus and Streptococcus agalactiae, the mean log somatic cell count (log SCC) increased from 5.06 to 5.77. The smallest changes occurred with Escherichia coli. Contagious pathogens, when compared with environmental pathogens, were more prevalent and common and created more profound quantitative and qualitative changes in SCC profiles. The second part of the study surveyed the diversity of contaminating pathogens and their effect on quantitative and qualitative profiles of somatic cells. M-PCR was used to determine the absence (M-PCR(-)) and presence of one (M-PCR(+1)), two (M-PCR(+2)), and three (M-PCR(+3)) major pathogens in raw milk samples. Quarter log SCC increased from 5.06 (for M-PCR(-1)) to 5.5 (for M-PCR(+1)), 5.7 (for M-PCR(+2)), and 6 (for M-PCR(+3)). Percent changes in polymorphonuclears (PMNs) were not significant between different quarters and parities but were significant between different farms in terms of pathogen diversity (P?相似文献   
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