首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
Mitogen-activated protein kinases (MAPKs) play important roles in the transduction of extracellular signals to the intracellular targets in all eukaryotes. Here, a cucumber cDNA designated CsNMAPK, encoding a mitogen-activated protein kinase was isolated using RT-PCR, 3′ and 5′ RACE. The full-length cDNA sequence contains 1636 bp and an open reading frame (ORF) of 1113 bp, which encodes 370 amino acid residues. According to the phylogenetic analysis, CsNMAPK belongs to subgroup I MAPK in plants. Northern blot analysis revealed that CsNMAPK expressed differently in response to excess NO3. And the CsNMAPK expression kinetics between a salt-resistant cultivar (Xintaimici) and a salt-sensitive cultivar (Shennongchunwu) was slightly different under 182 mmol L−1 NO3 treatment. The mRNA levels also increased after 24 h treatments with H2O2 and salicylic acid (SA), but decreased with abscisic acid (ABA) and low-temperature. However, there was no significant induction of CsNMAPK gene after 24 h drought and high-temperature treatments. Our results suggested that a MAP kinase cascade may function in excess NO3 and other abiotic stresses in cucumber.  相似文献   

2.
Gibberellins production by soil fungi received little attention, although substantial work has been carried out on other growth promoting aspects of soil borne fungi. We investigated gibberellins production and growth promoting capacity of a novel fungal strain of Neosartorya, which was isolated from the roots of Chinese cabbage (Bassica rapa L. ssp. pekinensis). Fungal culture filtrates (CF) obtained from pure cultures of 16 endophytic fungi were bioassayed on Waito-C, in order to investigate plant growth promoting capacity of these fungi. The fungal isolate CC-8 induced maximum shoot length of Waito-C (13.0 cm) as compared to control treatments. In a separate experiment, the CF of fungus CC-8 significantly promoted plant length and biomass of Chinese cabbage. The fungal CF also increased endogenous bioactive GA1 and GA4 contents of Chinese cabbage. Gibberellin analysis of CF of CC-8 showed presence of both physiologically active and non active gibberellins in higher concentrations (GA1, 1.42 ng/ml; GA3, 5.93 ng/ml; GA4, 11.36 ng/ml; GA7, 3.25 ng/ml; GA9, 0.79 ng/ml; GA15, 1.18 ng/ml). The culture filtrate of CC-8 produced higher amounts of GA3, GA4, GA7 and GA9 than wild type Fusarium fujikuroi, a well known gibberellins producing fungus. The fungal isolate CC-8 was later identified as a new strain of Neosartorya species on the basis of traditional and advance molecular techniques.  相似文献   

3.
Three greenhouse experiments were carried out to determine the growth, yield, nitrate, total N and S concentration in shoots, and water uptake of hydroponically grown Brassica rapa L. subsp. nipposinica var. chinoleifera and Brassica juncea L. In each experiment, daily photosynthetically active radiation (PAR) level was 5.0 mol m−2 (low), 6.8 mol m−2 (medium) or 9.0 mol m−2 (high). Plants were supplied with nutrient solutions having equal N concentrations of 11 mM in different forms: 100% NH4, 50% NH4 + 50% NO3, and 100% NO3. Nitrogen supplied as 100% NH4 reduced fresh and dry shoot biomass, leaf area, and leaf number in both Brassica species, especially at low and medium PAR levels. In both Brassica species, S concentrations were highest, while nitrate concentrations were lowest in leaves of plants grown at N supplied as 100% NH4. No differences in leaf nitrate concentrations were observed between 50% NH4 + 50% NO3 and 100% NO3 treatments. Low and high PAR levels increased the nitrate concentrations and decreased the N/S ratio in leaves of both crops compared to medium PAR level. Fresh shoot biomass was maximized in Brassica rapa when PAR level was above the medium value and nitrate was supplied in the nutrient solution as NO3 or as a mixture of 50% NO3 and 50% NH4. The highest fresh shoot biomass of Brassica juncea was observed in all nutrient solution treatments at high PAR level.  相似文献   

4.
Purple flowering stalk (Brassica campestris ssp. chinensis var.purpurea Hort.) was generally regarded as a recalcitrant species for microspore culture in Brassica crops. Conditions for reliable induction of microspore embryogenesis were studied in 12 genotypes of purple flowering stalk. A treatment of short heat shock to microspore by incubating at 32 °C for 18 h was suitable for the survival of microspores, sustained cell divisions, and further induced embryogenesis. Subsequently, the reduced concentration of macro salts (1/2 NLN) provided an optimal condition for the development of embryoids. Under the optimized conditions for microspore embryoid development, 10 genotypes responded to microspore culture with the frequencies ranging from 2.7 to 70.5 embryoids per dish. However, regenerated plants were obtained from 9 genotypes, and more than 75% these regenerated plants were double haploid. This report establishes an efficient protocol for microspore culture and offers great potential for DH breeding in purple flowering stalk.  相似文献   

5.
亚硫酸氢钠对白菜叶片硝酸盐还原及光合能力的影响   总被引:2,自引:0,他引:2  
 对日光温室内栽培的五叶一心白菜分别叶面喷施2、5、10 和15 mmol · L-1 亚硫酸氢钠(NaHSO3),以喷施清水为对照,分别在处理后0、4、8、12 和16 d 测定植株生物量、叶片的硝酸盐含量(NO3-)和硝酸还原酶(Nitrate reductase,NR)活性,同时测定叶片的光合参数和叶绿素荧光参数。结果表明,10 mmol · L-1 NaHSO3 处理后12 d 时的效应最为显著,与对照相比,叶片NO3-含量降低44.85%,NR 活性提高51.26%,且株高和地上部干质量均明显增加;同时显著提高其净光合速率(Pn)、羧化效率(CE)、最大羧化速率(Vcmax)、PSⅡ的原初量子效率(Q)和最大电子传递速率(ETRmax)。由此说明,对白菜叶面喷施NaHSO3,一方面能够在一定程度上提高NR 活性,拉动氮素的还原同化,降低NO3-的累积;另一方面能够通过提高PSⅡ电子传递能力和羧化反应速率,促进光合碳同化效率,可在碳骨架和能量供应上拉动氮代谢的还原同化。  相似文献   

6.
The objective of this study was to produce interspecific hybrids between an Ogura-cytoplasmic male sterile (CMS) line of zicaitai (Brassica campestris var. purupurea, 2n = 20) and cultivars of ornamental kale (Brassica oleracea var. acephala, 2n = 18) to develop a CMS system for hybrid seed production. Pollination with pollen grains of ornamental kales irradiated at a power output of 9.0 mW with a He–Ne laser for 3 min could overcome the cross-incompatibility between the species concerned. Intact hybrids could be efficiently produced from ovules cultured on Murashige and Skoog media supplemented by 0.2 mg l−1 6-benzyladenine. Chromosome number of hybrids was confirmed to be 2n = 19. Hybrids resembled ornamental kales in leaf morphology and in vernalization response. Pollens of hybrids had a sterile appearance. Moreover the hybridity of the putative hybrids was confirmed by RAPD data on a DNA fragment of 820 bp.  相似文献   

7.
The roots of 20 days old seedlings of tomato (Lycopersicon esculentum Mill.) at the time of their transplantation, were dipped in 10−8, 10−7, 10−6 or 10−5 M of 28-homobrassinolide (HBR) for 15, 30 or 45 min and were allowed to grow in earthen pots, in a net house. The leaves of the plants, at days 30 and 60, possessed elevated quantities of nitrate reductase (NR), carbonic anhydrase (CA) and the contents of chlorophyll. The values for all the above characteristics were significantly higher than that of the water-fed control. The fruits borned at the treated plants were more in number and possessed a lower quantity of ascorbic acid than the control. Moreover, the fruits at ripening, had higher levels of lycopene and β-carotene. Among the treatments, 15 min feeding of 10−8 M HBR proved best.  相似文献   

8.
Dianthus chinensis, Dianthus barbatus and Dianthus superbus are members of the Caryophyllaceae and are grown widely as ornamental plants. Information about relative genetic relationships can facilitate breeding programs. Here, we have compared two polymerase chain reaction (PCR)-based systems (sequence-related amplified polymorphisms (SRAPs) and inter-simple sequence repeats (ISSRs)) and morpological trait measurements for their relative effectiveness in estimating the genetic diversity found between 22 Chinese pink (D. chinensis) inbred-lines, one accession of D. barbatus and one accession of D. superbus. Interspecific differences were readily detected but the markers were less reliable in distinguishing the accessions according to their region of origin or in separating the wild species from the cultivars. Morphological traits were found to be the least effective genetic markers. The relative effectiveness of the three systems as markers for genetic diversity was concluded to be SRAP > ISSR > morphological traits, but the combined data from ISSR + SRAP analyses was superior to all three. The information generated by the SRAP marker system correlated more closely with morphological variability than did the ISSR marker system. The morphological markers of plant height/crown size ratio, lower leaf length, ovary shape index and calyx length showed strong correlations with the genetic diversity index (GDij, PPB(II) and PSB) as generated by the percentage of polymorphic bands and percentage of special bands of the PCR-based markers.  相似文献   

9.
The effect of different fertilisation (i.e. broadcast application and fertigation) and irrigation practices (tank sprinkler and drip irrigation) on yield, yield quality (nitrate content), nitrogen uptake of white cabbage (Brassica oleracea var. capitata L.) and the potential for N losses was assessed on sandy-loam agricultural soil. 15N-labelled fertiliser was used as a tracer. It was found that different practices significantly affected yield, nitrate content in plants, N uptake, as well as fertiliser use efficiency. The highest yield (93 t ha−1), plant N uptake (246 kg ha−1), and fertiliser use efficiency (42%) were obtained under treatment with broadcast fertilisation with farmer's practice of irrigation (tank sprinkler). The N surplus after harvest was −41 kg N ha−1, indicating the lowest potential for N losses. Treatment by fertigation and drip irrigation covering 100% of the crop's water requirements did not result in the highest yield as expected (72 t ha−1), the N surplus after harvest was about +38 kg ha−1. The lowest yield (58 t ha−1), fertiliser use efficiency (30%) and hence the highest potential for N losses (N surplus after harvest +68 kg ha−1) were found in treatment with broadcast fertilisation and drip irrigation covering 50% of the crop's water requirements.  相似文献   

10.
An in vitro plant regeneration protocol for pansy (Viola wittrockiana) cultivar ‘Caidie’ from petioles was established as following: callus induction on a half-strength MS medium supplemented with 0.45 μmol l−1 2,4-d plus 8.9 μmol l−1 BA, callus subculture on medium F (1/2MS with 4.5 μmol l−1 2,4-d, 2.7 μmol l−1 NAA and 0.44 μmol l−1 BA) and then on medium T (1/2MS with 4.5 μmol l−1 2,4-d, 2.7 μmol l−1 NAA and 2.2 μmol l−1 BA), shoot regeneration on medium D3 (MS media supplemented with 2.9 μmol l−1GA3, 23.6 μmol l−1 AgNO3, 0.02% active charcoal and 4.5 μmol l−1 TDZ), shoot multiplication on medium M (half-strength MS medium containing NAA 1.1 μmol l−1, TDZ 9.1 μmol l−1 and GA3 8.7 μmol l−1), and then shoot elongation and rooting on medium R (MS medium supplemented with 1.1 μmol l−1 NAA and 1.1 μmol l−1 BA). Subculture on appropriate medium was found to be important for successful shoot regeneration.  相似文献   

11.
12.
High-frequency somatic embryogenesis and shoot regeneration of broccoli (Brassica oleracea var. italica) were achieved. Cotyledon and hypocotyl explants from four varieties of broccoli were cultured on MS and modified MS media (mMS, supplemented with PG-96 organic components) with different combinations of growth regulator. The effects of genotypes, different explants, growth regulator combinations, organic components and AgNO3 on induction of calli and shoots were evaluated. The optimal media for inducting calli/shoots and roots were mMS medium containing 3% (w/v) sucrose and 0.8% (w/v) agar supplemented with NAA at 0.5 mg l−1, 6-BA at 3.0 mg l−1, AgNO3 at 4.0 mg l−1 and MS medium containing 3% sucrose and 0.8% (w/v) agar supplemented with NAA at 0.2 mg l−1, respectively. The callus induction percentages were over 90% in all four varieties; shoot induction percentage was 92.5% and the average number of shoot per explant was 4.1 from cotyledon explant in variety Bishan. In this study, we established high-efficient embryogenesis and shoot regeneration system of broccoli and analyzed genetic stability of regenerants at DNA level using RAPD molecular marker. Out of 62 arbitrary primers screened using PCR amplification, 79 polymorphic bands were amplified from 20 primers. The results demonstrated the genetic stability of regenerants from the same variety.  相似文献   

13.
Using Agrobacterium mediated transient expression method, plant bivalent expression vector pBI121 containing GUS as a report gene was transformed into lettuce (Lactuca sativa). Through designed orthogonal analysis, intact lettuce leaves infiltrated with 200 μM acetosyringone and 0.8 OD600 bacterial suspensions under vacuum for 30 min, then co-cultured at 24 °C for 6 ds produced a maximum GUS protein of 2.5% TSP with 21.39 nmol mg−1 min−1 MU activity, which was 19 times of the control (1.31 nmol mg−1 min−1 MU). Employed these optimized conditions HuIFN-beta was expressed in lettuce leaves. Western blot and antivirus bioactivity analyses confirmed the HuIFN-beta achieved by agrobacterium infiltration had a high biological activity (3.1 × 104 IU/mL). To our knowledge, it is the first detailed orthogonal optimizing study of Agrobacterium mediated transient expression and the first report on the production of the biologically active therapeutic proteins produced by Agrobacterium mediated transient expression in lettuce. In summary, transient expression by Agrobacterium vacuum infiltration can be adopted as an efficient, inexpensive and small-scaled plant expression system for therapeutic protein production.  相似文献   

14.
Pogonatherum paniceum (Lam.) Hack. is a rock plant with good potential for vegetative recovery on naked lands. A high frequency in vitro regeneration system was developed for P. paniceum. Calli were induced from explants of mature seeds, seedlings, young leaves, and stem segments on Murashige and Skoog (MS) medium supplemented with 1.0 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D), 2.0 mg L−1 α-naphthalene acetic acid (NAA) and 0.2 mg L−1 6-benzylaminopurine (BAP). High induction rates (59.57%) and regeneration rates (100%) were obtained from mature seed explants; calli were sub-cultured for over 2 years and still retained a high regenerative capacity. One seed explant resulted in 69,997 plants in 1 year. Shoot buds derived from calli were used for encapsulation in liquid MS medium containing 3% sucrose and two different alginate matrices (3% sodium alginate (w/v) + MS medium containing 3% sucrose and 3% sodium alginate + 1% activated carbon (w/v) + MS medium containing 3% sucrose) with a 20-min exposure to 2% CaCl2 and 0.3% bavistin (w/v). The capsule with 3.0% sodium alginate (w/v) and 1% activated carbon (w/v) showed a higher conversion rate (61.58%) and stronger plantlets under non-aseptic conditions. These systems are useful for the rapid clonal propagation and dissemination of artificial seed material of P. paniceum for eco-recovery.  相似文献   

15.
Elevated levels of nitrate-nitrogen (NO3-N) in the surficial aquifer above the drinking water quality standard, i.e. maximum contaminant limit (MCL; 10 mg L−1), have been reported in some part of central Florida citrus production regions. Soils in this region are very sandy (sand content >95%), hence are vulnerable to leaching of soluble nutrients and chemicals below the rooting depth of the trees. The objective of this research was to develop N and irrigation best management practices for citrus in sandy soils to maintain optimal crop yield and quality, and to minimize potential leaching of nitrate below the root zone. Six years of field experiment was conducted in a high productive (mean fruit yield > 80 Mg ha−1yr−1) >20-year-old ‘Hamlin’ orange trees [Citrus sinensis (L.) Osbeck] on ‘Cleopatra mandarin’ (Citrus reticulata Blanco) rootstock grown on a well drained Tavares fine sand (hyperthermic, uncoated, Typic Quartzipsamments) in Highland county, FL. Nitrogen rates ranged from 112 to 280 kg ha−1 yr−1 applied as fertigation (FRT), water soluble granular (WSG), 50:50 mix of FRT and WSG, and controlled-release fertilizer (CRF). Tensiometers were used to monitor the soil water content as a basis to schedule optimal irrigation. Fruit yield response over the entire range of N rates was greater for the FRT and WSG sources as compared to that for the WSG + FRT or CRF sources. Using the regression analysis of the fruit yield in relation to N rate, the optimum N rate appeared to be at 260 kg ha−1 yr−1. Based on fruit production response in this study, the N requirement for production of 1 Mg of fruit varied from 2.2 to 2.6 kg across four N sources. This study demonstrated an increased N uptake efficiency, as a result of best management of N and irrigation applications. The optimal N and K concentration in the 4–6-month-old spring flush leaves were 26–30, and 15–18 g kg−1, respectively. However, fruit yield response showed no significant relationship with concentrations of P in the 4–6-month-old spring flush leaves over a range of 0.8–2.4 g kg−1. The results of fate and transport of N in soil and in soil solution with application of different rates and sources of N, and components of citrus tree N budget, are reported in a companion paper.  相似文献   

16.
In order to increase the fruit weight of a shriveled-seed cultivar, trees of ‘Yu Her Pau’ litchi (Litchi chinensis Sonn.) growing in Taiwan were sprayed with Gibberellic acid (GA3) (ProGibb®, 20% of GA3) at 5 and 10 mg/l 14 days after full bloom (AFB) over 2 years. Both concentrations of GA3 significantly increased fruit longitudinal and transversal diameter, and fruit, aril and pericarp weight (40–41 and 37–38 mm, and 27.3–28.4, 21.7–22.7 and 5.0–5.3 g, respectively) compared with control (35–36 and 33–34 mm, and 22.3–22.4, 17.8–17.9 and 3.9–4.0 g), but had no significant effects on seed weight, percentage of aril weight of total fruit weight or total soluble solids (0.5–0.7 g, 78.9–80.3% and 18.1–19.0 °Brix, respectively). Fruit characteristics within the two concentrations of GA3 showed no significant difference. The results indicated that sprays of GA3 should be evaluated in ‘Yu Her Pau’ commercial orchards, and in other elite cultivars.  相似文献   

17.
This work examined the effect of nitrogen source and medium buffering on the micropropagation of Eucalyptus marginata Donn ex Sm. The number of shoots was increased when media contained 2-(N-morpholino) ethanesulfonic acid (MES) but this increase was minor and only applied to one of the two clones tested. Highest root production was obtained when the medium contained 7.5 mM nitrogen in a ratio of 2NO3:1NH4+ and was buffered with 10 mM MES. In the rooting medium the pH was influenced most significantly by the nitrogen source, and then whether the medium was buffered. The media pH remained relatively constant when nitrate was the sole nitrogen source and this was assisted by the addition of 10 mM MES. Lower concentrations (<10 mM) of MES were less effective in buffering media over a four-week culture period in both shoot multiplication and rooting medium.  相似文献   

18.
Agrobacterium-mediated transformation for both Melastoma malabathricum and Tibouchina semidecandra were optimized using green fluorescent protein (GFP) as a reporter. The binary vector pCAMBIA1304 harboring the modified green fluorescent protein (mgfp) gene driven by the CaMV 35S promoter was used. Parameters optimized were bacterial strain, bacterial concentration, pre-culture period, co-cultivation period, immersion time, acetosyringone concentration and wounding type. Results obtained were based on the percentage of GFP expression which was observed 3 days post-transformation. Agrobacterium tumefaciens strain LBA4404 and EHA105 at concentration 1 × 107 cfu ml−1 (OD600nm 0.8) showed the highest virulence on M. malabathricum and T. semidecandra, respectively. Four days of pre-culture and 2 days of co-cultivation were optimum for M. malabathricum transformation, while 3 days of pre-culture and co-cultivation for T. semidecandra. Result also showed that 60 min of immersion and addition of 200 μM acetosyringone gave the highest percentage of positive transformants for both M. malabathricum and T. semidecandra. Mild wounding also significantly increased the efficiency of M. malabathricum transformation.  相似文献   

19.
Dendrobium nobile Lindl. is a popular temperate Chinese orchid commonly marketed as a traditional medicinal plant. Seedlings of Dendrobium nobile Lindl. produced floral buds (33.3–34.8%) precociously on a defined basal medium (1/2 MS) containing paclobutrazol (PP333) at 0.5 mg L−1 or thidiazuron (TDZ) at 0.1 mg L−1 within 4 months of culturing. The frequency of floral buds formation can be further increased to 95.6% by growing seedlings in a PN (PP333 0.3 mg L−1 + NAA 0.5 mg L−1)-containing medium followed by transfer onto 1/2 MS medium with PP333 and TDZ (PP333 + TDZ). However, flower developed was deformed under 25 °C but it developed fully when grown in a lower temperature regime (23 °C/18 °C, light/dark) for 45 days. Under optimal condition, in vitro flowering was observed about 6 months after seed sowing.  相似文献   

20.
Since the response of cuttings to raised CO2 concentration is not documented, controlled atmosphere (CA) storage of kalanchoe cuttings at combinations of high carbon dioxide and low oxygen levels was investigated to study the feasibility of using CA to sustain quality of cuttings prior to planting. During storage, stomata opening and plant fresh weight (FW) were measured, and root formation (RF) was recorded post storage. Storage atmosphere composition (10/2, 15/2, or 15/5; kPa CO2/kPa O2), storage duration (9 or 19 days), and cutting type (rooted or un-rooted) affected stomata conductance (Gs), and influenced FW and subsequent RF in cuttings of kalanchoe ‘Yellow Josefine’. In CA stored plants, Gs was high, 60–160 mmol m−2 s−1, indicating open stomata, whereas in control plants Gs was low, 5–14 mmol m−2 s−1, indicating closed stomata. Generally Gs values were higher for un-rooted than for rooted cuttings. Overall, cutting FW was reduced by CA storage with no significant differences in FW reduction between the CA treatments. RF of un-rooted CA stored cuttings was comparable to that of controls, whereas for rooted cuttings controls grew better than CA stored cuttings. CA at 10 kPa CO2 and 2 kPa O2 for 2–3 weeks could sustain un-rooted cuttings, in a pests-free state whilst retaining the ability of the cuttings RF. The results showed that stomata aperture may be altered by high CO2 concentration combined with low O2, and results indicated that this effect was not only caused by high CO2 but also by low O2 concentration. In addition, the results indicated that CA storage, stomata conductance, and water stress of kalanchoe cuttings may be correlated. Monitoring Gs of leaves of cuttings could be used as a non-destructive indicator of storability and quality status. Based on the novel positive preliminary results reported here, a protocol that focuses on minimising water loss should be developed and optimised for kalanchoe.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号