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1.
A highly efficient regeneration protocol for oilseed crop Crambe abyssinica has been developed using hypocotyls as explants in this study. Crambe is a potential engineering oilseed crop for industrial purposes as it contains 55-60% erucic acid in its oil and, more importantly, it does not outcross with any food oil seed crops. However, the low regeneration frequency with the currently available protocols is still a limiting factor for genetic modification of Crambe. In this study, we investigated the effects of N-source, C-source, AgNO3, cultural conditions as well as the concentration and combination of plant growth regulators (PGR) on the regeneration frequency of C. abyssinica. The results showed that all these factors, especially the N-source and PGR concentrations and combinations, played an important role in shoot regeneration. Among all the factors tested, the combination of using hypocotyls from C. abyssinica cv. galactica, the Lepiovre basal medium supplemented with 16 g l−1 glucose, 0.5 g l−1 AgNO3, 2.2 mg l−1 thidiazuron (TDZ), 0.5 mg l−1 α-naphthaleneacetic acid (NAA), 2.5 g l−1 Gelrite, seeds germinated in dark for 3 days and explants cultured in light, gave the best regeneration frequency (over 95%). The results also suggest that reducing the content of NH4+ or keeping a suitable NO3−/NH4+ ratio in the regeneration medium would be crucial to Crambe shoot regeneration.  相似文献   

2.
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3.
Factors influencing in vitro regeneration through direct shoot bud induction from hypocotyl explants of Jatropha curcas were studied in the present investigation. Regeneration in J. curcas was found to be genotype dependent and out of four toxic and one non-toxic genotype studied, non-toxic was least responsive. The best results irrespective of genotype were obtained on the medium containing 0.5 mg L−1 TDZ (Thidiazuron) and in vitro hypocotyl explants were observed to have higher regeneration efficiency as compared to ex vitro explant in both toxic and non-toxic genotypes. Adventitious shoot buds could be induced from the distal end of explants in all the genotypes. The number of shoot buds formed and not the number of explants responding to TDZ treatment were significantly affected by the position of the explant on the seedling axis. Explants from younger seedlings (≤15 days) were still juvenile and formed callus easily, whereas the regeneration response declined with increase in age of seedlings after 30 days. Transient reduction of Ca2+ concentrations to 0.22 g L−1 in the germination medium increased the number of responding explants.Induced shoot buds, upon transfer to MS medium containing 2 mg L−1 Kn (Kinetin) and 1 mg L−1 BAP (6-benzylamino purine) elongated. These elongated shoots were further proliferated on MS medium supplemented with 1.5 mg L−1 IAA (indole-3-acetic acid) and 0.5 mg L−1 BAP and 3.01-3.91 cm elongation was achieved after 6 weeks. No genotype specific variance in shoot elongation was observed among the toxic genotypes except the CSMCRI-JC2, which showed reduced response. And for proliferation among the toxic genotypes, CSMCRI-JC4 showed highest number of shoots formed. Among the rest, no significant differences were observed. The elongated shoot could be rooted by pulse treatment on half-strength MS medium supplemented with 2% sucrose, 3 mg L−1 IBA (indole-3-butyric acid), 1 mg L−1 IAA, 1 mg L−1 NAA (α-naphthalene acetic acid) and subsequent transfer on 0.25 mg L−1 activated charcoal medium. The rooted plants could be established in soil with more than 90% success. No significant differences were observed in rooting of shoots in the different toxic genotypes. However, rooting response was reduced in non-toxic genotype as compared to toxic genotypes.  相似文献   

4.
Avena sativa L. (Poaceae) has been reported to have traditional utilization against skin diseases and inflammation. Therefore, in this study, the n-hexane, ethyl acetate, ethanol, and water extracts of A. sativa were investigated for their wound healing and antioxidant activities. Total phenol and flavonoid contents of the extracts were established spectrophotometrically. For the wound healing activity, linear incision and circular excision models on rats and mice were evaluated with a standard ointment Madecassol®. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelating, and ferric-reducing antioxidant power (FRAP) assays. Significant wound healing activity was observed with the ointment formulation of the ethanol extract at 1% concentration. The histopathological examination results also supported the outcome of both linear incision and circular excision wound models. All of the extracts exerted low antioxidant activity in the applied assays. The present study provides a scientific evidence for the traditional usage of A. sativa in the management of wound healing.  相似文献   

5.
A simple and rapid method for micropropagation of succulent, salt accumulator and extreme halophyte Salicornia brachiata has been established for the first time using shoot tips and nodes. Individually, BA showed significant response compared to Kn and in combinations, improved shoot proliferation was observed with BA + NAA than BA + 2,4-D, however no significant response was observed with BA + IAA. Percentage of shoot response significantly increased with NaCl treatment in the combination of BA + NAA while BA + 2,4-D + NaCl combination showed reduced shoot proliferation followed by demises of most of cultures. Efficient shoot proliferation was observed with combinations BA (8.9 μM) + NAA (5.37 μM) + NaCl (500 mM) and BA (13.3 μM) + NAA (5.37 μM) + NaCl (250 mM) indicating that NaCl is required for the micropropagation. The developed method will facilitate functional analysis of novel salt responsive gene(s) isolated from S. brachiata and propagation of industrially important elite accessions.  相似文献   

6.
The study revealed, for the first time, accumulation of spilanthol, an antiseptic alkylamide, in in vitro cultures of Spilanthes acmella Murr., a medicinal plant of immense commercial value. To achieve this, in vitro shoots were regenerated via direct organogenesis from leaf-disc explants of Spilanthes. Shoots were induced in the presence of N6-benzylaminopurine (BAP) alone or in combination with either α-naphthalene acetic acid (NAA) or Indole-3-acetic acid (IAA) in Murashige and Skoog medium. The best treatment for shoot regeneration was MS + BAP (5.0 μM) + IAA (5.0 μM), which promoted adventitious shoot proliferation in >82% cultures with an average of 5.3 shoots per explant. Regenerated shoots rooted spontaneously with a frequency of 100% on half strength MS medium (major salts reduced to half strength) containing 50 g l−1 sucrose. The plantlets were acclimatized successfully with 90% survival rate. Additionally, ploidy stability of the regenerated plants was assessed by flow cytometry which showed that all investigated plants had the similar ploidy as that of the mother plant. For spilanthol identification, peaks eluted from HPLC were analyzed by mass spectrometry with its characteristic fragmentation pattern. For quantification studies, calibration curve was generated, which revealed a higher amount of spilanthol content (3294.36 ± 12.4 μg/g DW) in the leaves of in vitro plants compare to those of in vivo plants (2703.66 ± 9.6 μg/g DW of spilanthol). An efficient multiplication frequency, ploidy stability and enhanced spilanthol accumulation ensure the efficacy of the protocol developed for this industrially important medicinal plant.  相似文献   

7.
We tested here five distinct in vitro screening methods assessing Mycosphaerella graminicola resistance to strobilurin fungicides: (i) spotting on agar medium, (ii) spore germination on agar medium, (iii) growth in microplates without and (iv) with the addition of Alamar blue and (v) screening of the cytochrome b substitution conferring resistance G143A. The assays were performed by assessing resistance to azoxystrobin of 32 French M. graminicola strains and the two reference strains IPO323 and IPO94269 from the Netherlands. The microplate Alamar blue assay displayed high standard deviations from all growth averages, hence reporting the strong lack of reliability of this method. As expected, the two reference strains were found sensitive with all other methods. In agreement with the disruptive resistance of M. graminicola to single-site fungicides, the half maximal inhibitory concentration (IC50) values of sensitive and resistant strains displayed a bimodal distribution pattern with each type of assay. All strains carrying G143 or A143 alleles were found sensitive or resistant respectively with each bioassay. Although the absolute IC50 value for each strain varied among assays, the ranking of strains according to their IC50 values was overall conserved with all assays. Finally, the frequency of strobilurin resistant haplotypes within France was investigated by screening G143A in 82 strains isolated in 2005 year from 12 localities. Results showed a marked gradual decrease in resistance distribution from 70% in northern to 30% and 0% in central and southern France, respectively. The accuracy of each method as well as the widespread and incidence of strobilurin resistance within the French population of M. graminicola have been discussed.  相似文献   

8.
Stevia rebaudiana is a valuable medicinal plant species and it is being used for the treatment of diabetes. Currently, there is a high demand for raw material of this medicinal herb due to ever increasing diabetes disorder among the population. In order to meet the increased demand an efficient in vitro propagation of S. rebaudiana was established. Nodal explants collected from the field were cultured on MS basal medium fortified with different concentrations of BAP (0.5-3.0 mg/l) and KIN (0.5-3.0 mg/l) individually for shoot bud induction. In vitro derived nodal buds were cultured on MS medium supplemented with different concentrations (0.5-3.0 mg/l) of BAP and KIN for multiple shoot bud regeneration. In the second experiment, in vitro derived buds were placed on MS medium supplemented with different concentrations of BAP (0.5-3.0 mg/l) in combination with 0.5 mg/l IAA or IBA or NAA for shoot bud multiplication. The highest frequency (94.50%) of multiple shoot regeneration with maximum number of shoots (15.69 shoots/explant) was noticed on MS medium supplemented with 1.0 mg/l BAP. For large scale plant production, in vitro derived nodal bud explants were cultured on MS medium fortified with 1.0 mg/l BAP, in which about 123 shoots/explant were obtained after three subcultures on the same media composition. Elongated shoots (>2 cm) dissected out from the in vitro proliferated shoot clumps were cultured on half-strength MS medium containing different concentrations of NAA (0.1-0.5 mg/l) and/or MS medium fortified with various concentrations (0.5-2.0 mg/l) of auxins (NAA, IAA and IBA) for root induction. Highest frequency of rooting (96%) was noticed on half-strength MS medium augmented with 0.4 mg/l NAA. The rooted plantlets were successfully transferred into plastic cups containing sand and soil in the ratio of 1:2 and subsequently established in the greenhouse. The present in vitro propagation protocol would facilitate an alternative method for rapid and large-scale production of this important antidiabetic medicinal plant.  相似文献   

9.
The distribution patterns of Apple stem grooving virus (ASGV) and Apple chlorotic leaf spot virus (ACLSV) in in vitro-cultured pear plants were investigated using in situ tissue-printing hybridization (TPH) and tissue blotting immunoassay (TBIA) to detect viral RNAs and coating proteins. Both ASGV and ACLSV showed high concentrations in the tip of the pear shoots and lower concentrations in the middle stem. The highest viral RNA titers were found in the phloem parenchyma of vascular bundles. Monitoring of viral RNA concentrations was conducted on infected in vitro-cultured pear plants during thermotherapy using TPH combined with X-ray film exposure in serial cross sections. No viral RNA of ACLSV or ASGV was detected in less than 2 mm and 0.5 mm long tips, respectively. The heat treatment was less effective to reduce virus titers in the bottom shoot. The obtained results would assist in the selection of tips with proper sizes from pear shoots pre- and post-thermotherapy for the production of virus-free pear plants by meristem culture.  相似文献   

10.
Randomly amplified polymorphic DNA markers (RAPD) were employed to assess the level of genetic stability of long term micropropagated prickly pear (Opuntia ficus-indica) plantlets.Thirteen micropropagated plantlets were chosen from a clonal collection of shoots that originated from a single mother shoot. This clonal collection had been maintained under in vitro culture conditions for at least 5 years, as achieved for the time by axillary branch multiplication in Opuntia ficus-indica.Twenty arbitrary primers were used to compare RAPD patterns between in vitro raised material and the mother plant. Only 11 primers were found to yield distinct and reproducible amplification products resulting in a total of 87 amplified products, out of which 82 bands were monomorphic across all the plantlets and 5 showed polymorphisms.Cluster analysis performed on the basis of similarity indices indicated that all micropropagated plantlets and their mother plant grouped together in one major cluster with a 91% level of similarity.Low level of genetic variation has been detected, as polymorphic bands accounted for just 2.79% of the total genetic variation. This very low level of genetic variation, despite more than 5 years of in vitro culture, demonstrates the genetic stability of Opuntia ficus-indica and indicates that the axillary branch multiplication method is highly reliable for the multiplication of genetically true-to-type plant material.The high degree of clonal fidelity detected here, recommend the use of axillary-branching micropropagation technique for the safe in vitro conservation of prickly pear interesting genetic resources.  相似文献   

11.
In situ melting and crystallization of short-linear α-1,4-glucan (short-chain amylose, or SCA) from debranched waxy starches were investigated by synchrotron wide-angle X-ray diffraction. Amorphous SCA was prepared by dissolving completely debranched waxy starches in alkaline solution and neutralized by hydrochloric acid. When hydrated with 50% water at 25 °C, all amorphous SCA crystallized immediately and gave a B-type structure. The SCA from debranched waxy potato starch had a longer average chain length and a higher melting temperature but relatively lower crystallinity upon hydration; it was not completely melted at 100 °C and retained its original B-type structure during rapid cooling. In contrast, the SCA from debranched waxy wheat and waxy maize starches had a large portion of low molecular weight fractions, a higher crystallinity upon hydration, and a lower melting temperature. These differences suggest that amylopectin short chains crystallized more readily but their crystals were weaker than those of long chains. After the B-type crystals of hydrated SCA from waxy wheat and waxy maize starches melted, they reformed into the A-type polymorph upon rapid cooling. The thermal properties showed that the A-type polymorph of debranched waxy wheat and waxy maize starches had a higher melting temperature than their B-type structure.  相似文献   

12.
Verticillium wilt (VW), caused by Verticillium dahliae Kleb., has become one of the most serious problems in cotton (Gossypium hirsutum L.). The use of resistant cultivars has long been considered the most practical and effective means of control. The objective of this work was to study the quantitative genetic basis of fiber traits under Verticillium conditions in upland cotton by using five genotypes and their possible crosses without reciprocals, selecting simultaneously for quality fiber, resistance, and agronomic characteristics. Five cotton cultivars and 10 F1s from half diallel crosses were analyzed for quality fiber under VW conditions. The fiber length, uniformity, strength, elongation, and micronaire were measured during two crop seasons at two different sites each year, consistently in plots with soil naturally infested with Verticillium. Genetic components of variance were analyzed using the Hayman model. Analysis of variance for all traits showed significant differences between genotypes, with the genotype–site interaction in most of the studied traits except for fiber length and micronaire. Both the additive genetic variance component (D) and dominance genetic variance components (H1 and H2) were present in all traits. D was the most important component for uniformity, strength, elongation, and micronaire. Elongation was the trait most correlated with seed-cotton yield. Strength and micronaire were the traits most correlated with VWI. Broad-sense heritability was high for all the traits studied. Narrow-sense heritability was high for uniformity, strength and elongation, and moderate for length and micronaire.  相似文献   

13.
Several broomrape species including Orobanche crenata, Orobanche foetida and Phelipanche aegyptiaca are reported to infect various grain and forage legumes in the Mediterranean and West Asia. Pea (Pisum sativum) is severely damaged by O. crenata, but there are no reports on O. foetida or P. aegyptiaca infection. We report here that pea can induce high germination of seeds of O. crenata, O. foetida and P. aegyptiaca but only O. crenata success infecting pea roots and developing further. Some differences in levels of infection by O. crenata were observed among pea accessions what can be exploited in pea resistance breeding programmes. On the contrary, all pea accessions studied were highly resistant to infection by both O. foetida and P. aegyptiaca, preventing any tubercle attachment and development. This makes pea a promising candidate as trap crop for O. foetida and P. aegyptiaca seed bank demise in infested soils.  相似文献   

14.
Preharvest sprouting is common in cereals that lack grain dormancy if maturing grain is exposed to rain. Over three successive seasons wheat genotypes with a range of dormancy levels, were exposed to moisture stress and periods of high temperature stress (>30 °C) in controlled field trials. Dormancy assessments were based on a germination index of hand threshed grain throughout grain filling. There were three main results. First, moisture stress combined with consistently high temperature during grain filling was associated with induced dormancy in Cunderdin, (germination index of 0.41) in a normally non-dormant genotype (germination index normally >0.80), but no additional dormancy in DM 2001, a dormant genotype (germination index normally <0.10). In contrast sudden heat shocks (>30 °C max. for >12 days) at 30–50 days post-anthesis reduced dormancy, germination index increase of 0.42 on average across five genotypes. Secondly, whilst dormancy was affected by moisture and heat stress, genotypes maintained their relative rankings across environments and genotype had the most effect on dormancy (70–92% of the variation in germination index) with DM 2001 and DH 22 more dormant than DH 56, DH 45 and Cunderdin. Finally, the effect of environment was different for different genotypes; those with partial dormancy (germination index usually 0.20–0.50, DH 56 and DH 45) were most influenced by the environmental conditions with germination indexes ranging from 0.06 to 0.85 depending on environment. Consequently avoidance of high temperatures, moisture stress, and maturity × stress interactions, are important prerequisites in screening for genotypes with genetic differences in dormancy.  相似文献   

15.
F. Kobayashi 《Crop Protection》2011,30(11):1514-1518
To establish a method for disinfecting hydroponic culture solutions using ozone microbubbles (OMB), we examined the disinfectant activity of OMB against Fusarium oxysporum f. sp. melonis and Pectobacterium carotovorum subsp. carotovorum in infected plant roots. OMB had a higher solubility and remained in the water for a longer period than ozone millibubbles, resulting in extremely high disinfecting activity against both phytopathogens. Furthermore, disinfectant activity and durability of OMB-treated water against both phytopathogens increased with an increase in the initial concentration of dissolved ozone. Therefore, these results suggest that OMB may be suitable for use as a new disinfectant against phytopathogens in hydroponic culture solutions.  相似文献   

16.
Gossypium hirsutum L. is the predominant cotton of commerce and all cultivars of this species are susceptible to the reniform nematode, Rotylenchulus reniformis. To introgress resistance to R. reniformis into the tetraploid 2(AD1) G. hirsutum, a resistant diploid A2-genome Gossypium arboreum accession (A2-190) was crossed with a hexaploid 2((AD1)D4) bridging line (G 371) to obtain a tetraploid triple-species hybrid. The triple-species hybrid was back-crossed to G. hirsutum and a population of 277 BC1 individuals was produced. The BC1s and controls were assayed in growth chambers for resistance to R. reniformis. Fortuitously, the hexaploid bridging line G 371 was also found to be resistant to R. reniformis. The BC1 segregated 3:1, resistant:susceptible, indicating that resistance was conferred by dominant genes at two different loci, with each originating from a distinct germplasm source. This study demonstrated that it is possible to introgress and pyramid genes for resistance to R. reniformis in G. hirsutum.  相似文献   

17.
The practice of rubbing different plant material juices or extracts into the skin to relieve pain and rheumatic symptoms is deeply rooted in folk medicine and has been used for a long time. Several common species, usually available in agroecosystems of the Iberian Peninsula, were/are used for topical medicinal preparations as reported in recent ethnobotanical surveys. Based on these studies, the fruits of three relevant species (Bryonia dioica or white-bryony, Lonicera periclymenum or common honeysuckle and Tamus communis or black-bryony) were gathered and different analyses and assays were performed in order to characterize their phytochemical composition and to find biologically active compounds for pharmaceutical application. Black-bryony ripened fruits revealed the highest antioxidant properties which are in agreement to its highest concentration in phenolics, flavonoids, ascorbic acid, tocopherols and lycopene. The studied fruits revealed interesting antioxidant properties and bioactive phytochemicals that could provide scientific evidence for their folk uses as anti-inflammatory species.  相似文献   

18.
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19.
Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) are highly effective against the European corn borer, Ostrinia nubilalis (Hübner), and the closely related Asian corn borer, Ostrinia furnacalis (Guenée). Since the registration of Bt corn hybrids in the U.S. in 1996, there has been a great deal of information generated on O. nubilalis. However, relatively little information exists for O. furnacalis. To help determine whether the information generated for O. nubilalis can be leveraged for decisions regarding the use of transgenic Bt corn against O. furnacalis, experiments were designed to determine whether the pattern of sensitivity to various Bt Cry1 toxins is similar between the two species. Test insects included laboratory-reared O. furnacalis originating from Malaysia, a Bt-susceptible laboratory colony of O. nubilalis maintained at the University of Nebraska-Lincoln (UNL) and an out-group consisting of the sugarcane borer, Diatraea saccharalis (F.), from Louisiana which represents a different genus from the same family. O. furnacalis and O. nubilalis exhibited a similar pattern of susceptibility to all the Cry1 toxins and were highly susceptible to the range of Bt toxins tested including Cry1Aa, Cry1Ab, Cry1Ac and Cry1F. Both of the Ostrinia species were more tolerant to Cry1Ba compared with D. saccharalis, although sensitivity of O. furnacalis was intermediate and did not differ significantly from that of O. nubilalis and D. saccharalis. D. saccharalis was also susceptible to the range of toxins tested but unlike the two Ostrinia species, was more tolerant to Cry1F and more susceptible to Cry1Ba. These results indicate that both of the Ostrinia corn borer species are similar in sensitivity to the Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba and Cry1F toxins, thus suggesting shared toxin receptors and mechanisms of toxicity for the two species.  相似文献   

20.
The characteristically clustered occurrence and low level of mobility of Heterodera schachtii and Rhizoctonia solani in the soil and the induction of stress symptoms in the sugar beet canopy make them ideal targets for site-specific arrangements with precision agriculture tools. A field site infested with H. schachtii and R. solani was investigated in 2009 with near-range and aerial hyperspectral sensors during the growing season. At 31 sample points ground truth data for incidence and severity of the two organisms were collected and geo-referenced. Spectral vegetation indices computed from reflectance measurements obtained from two flight campaigns (AISA, 17th of June; HyMap, 28th of August) and the near-range spectroradiometers were significantly correlated (P < 0.01) with symptoms caused by the nematode or Rhizoctonia crown and root rot. A supervised classification with Spectral Angle Mapper of leaf symptoms induced by the organisms resulted in a classification accuracy of 72 and 64% for the AISA and HyMap data, respectively. The results demonstrated that remote sensing in combination with geographic information system technologies can be used effectively for the detection and mapping of symptoms caused by beet cyst nematode and Rhizoctonia crown and root rot.  相似文献   

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