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1.
Tuber huidongense and T. liyuanum are common commercial white truffles in China that belong to the Rufum and Puberulum groups of the genus Tuber, respectively. Their mycorrhizae were successfully synthesized with two native trees—Castanea mollissima and Pinus armandii—under greenhouse conditions. The identities of the mycorrhizae were confirmed through internal transcribed spacer (ITS) sequence analyses, and their morphological characteristics were described. All of the obtained mycorrhizae have an interlocking pseudoparenchymatous mantle, which is a typical feature of truffle mycorrhizae. The mycorrhizae of T. huidongense on the two trees have hyaline branched emanating hyphae, similar to the documented mycorrhizae of the Rufum group. The unramified, spiky, and hyaline cystidia on the mycorrhizae of T. liyuanum with both C. mollissima and P. armandii further confirmed that this characteristic is constant for the mycorrhizae of the Puberulum group. The successful mycorrhizal syntheses on the two nut-producing trees will be of economic importance in the cultivation of the two truffles.  相似文献   

2.
Boletus edulis Bull. is one of the most economically and gastronomically valuable fungi worldwide. Sporocarp production normally occurs when symbiotically associated with a number of tree species in stands over 40 years old, but it has also been reported in 3-year-old Cistus ladanifer L. shrubs. Efforts toward the domestication of B. edulis have thus focused on successfully generating C. ladanifer seedlings associated with B. edulis under controlled conditions. Microorganisms have an important role mediating mycorrhizal symbiosis, such as some bacteria species which enhance mycorrhiza formation (mycorrhiza helper bacteria). Thus, in this study, we explored the effect that mycorrhiza helper bacteria have on the efficiency and intensity of the ectomycorrhizal symbiosis between C. ladanifer and B. edulis. The aim of this work was to optimize an in vitro protocol for the mycorrhizal synthesis of B. edulis with C. ladanifer by testing the effects of fungal culture time and coinoculation with the helper bacteria Pseudomonas fluorescens Migula. The results confirmed successful mycorrhizal synthesis between C. ladanifer and B. edulis. Coinoculation of B. edulis with P. fluorescens doubled within-plant mycorrhization levels although it did not result in an increased number of seedlings colonized with B. edulis mycorrhizae. B. edulis mycelium culture time also increased mycorrhization levels but not the presence of mycorrhizae. These findings bring us closer to controlled B. edulis sporocarp production in plantations.  相似文献   

3.
The present study aimed at evaluating the role of captive scarlet ibises (Eudocimus ruber) and their environment as reservoirs of Aeromonas spp. and Plesiomonas spp., and analyzing the in vitro antimicrobial susceptibility and virulence of the recovered bacterial isolates. Thus, non-lactose and weak-lactose fermenting, oxidase positive Gram-negative bacilli were recovered from cloacal samples (n = 30) of scarlet ibises kept in a conservational facility and from water samples (n = 30) from their environment. Then, the antimicrobial susceptibility, hemolytic activity and biofilm production of the recovered Aeromonas spp. and Plesiomonas shigelloides strains were assessed. In addition, the virulence-associated genes of Aeromonas spp. were detected. Ten Aeromonas veronii bv. sobria, 2 Aeromonas hydrophila complex and 10 P. shigelloides were recovered. Intermediate susceptibility to piperacillin-tazobactam and cefepime was observed in 2 Aeromonas spp. and 1 P. shigelloides, respectively, and resistance to gentamicin was observed in 4 P. shigelloides. The automated susceptibility analysis revealed resistance to piperacillin-tazobactam and meropenem among Aeromonas spp. and intermediate susceptibility to gentamicin among P. shigelloides. All Aeromonas isolates presented hemolytic activity, while 3 P. shigelloides were non-hemolytic. All Aeromonas spp. and 3/10 P. shigelloides were biofilm-producers, at 28 °C, while 10 Aeromonas spp. and 6/10 P. shigelloides produced biofilms, at 37 °C. The most prevalent virulence genes of Aeromonas spp. were asa1 and ascV. Scarlet ibises and their environment harbour potentially pathogenic bacteria, thus requiring monitoring and measures to prevent contamination of humans and other animals.  相似文献   

4.
The role of 4.1 or 8.2 μM meta-topolin (mT) on shoot multiplication, rooting and ex vitro acclimatization of micropropagated Corylus colurna L., a promising non-suckering rootstock for hazelnut (Corylus avellana L.), was examined in comparison to N6-benzyladenine (BA), the most used cytokinin in tissue culture of Corylus spp. The influence of 8.2 μM mT and BA on photosynthetic pigments content and antioxidant enzymes activity, catalase (CAT) and guaiacol peroxidase (POD), in regenerated shoots, and on the preparation of the rootstock for micrografting was also evaluated. The highest shoot multiplication was recorded on medium containing 8.2 μM mT and an overall positive effect of mT on growth and quality of micropropagated shoots was found. The highest chlorophyll a content (1.236 mg g?1 fresh weight, FW) and chlorophyll a/b ratio (2.48), and the lowest total carotenoids content (0.292 mg g?1 FW) and CAT activity (25.8 μmol min?1 mg?1 protein) were detected after 8.2 μM mT application, while no significant differences were found in chlorophyll b content and POD activity between the two cytokinins. The best rhizogenesis response (98% for 4.1 μM and 100% for 8.2 μM mT) and ex vitro acclimatization competence (higher than 78%) were exhibited from shoots multiplied on mT. Furthermore, the multiplication of rootstock on mT allowed obtaining the highest (70%) response of successful micrografting. The present findings provide the first evidence of the successful applicability of mT in C. colurna tissue culture and development of micrografted plantlets.  相似文献   

5.
In addition to the already known cagA gene, novel genetic markers have been associated with Helicobacter pylori (H. pylori) virulence: the dupA and vacAi genes. These genes might play an important role as specific markers to determine the clinical outcome of the disease, especially the vacAi gene, which has been expected to be a good marker of severe pathologies like gastric adenocarcinoma. In the present study, the association of cagA, dupA, and vacAi genes with gastroduodenal pathologies in Chilean patients was studied. One hundred and thirty-two patients positive for H. pylori were divided into two groups—non-severe and severe gastric pathologies—and investigated for the presence of cagA, dupA, and vacAi H. pylori virulence genes by PCR. The cagA gene was detected in 20/132 patients (15.2%), the vacAi1 gene was detected in 54/132 patients (40.9%), the vacAi2 gene was detected in 26/132 patients (19.7%), and the dupA gene was detected in 50/132 (37.9%) patients. Logistic regression model analysis showed that the vacAi1 isoform gene in the infected strains and the severity of the diseases outcome were highly associated, causing severe gastric damage that may lead to gastric cancer (p < 0.0001; OR = 8.75; 95% CI 3.54–21.64). Conversely, cagA (p = 0.3507; OR = 1.62; 95% CI 0.59–4.45) and vacAi2 (p = 0.0114; OR = 3.09; 95% CI 1.26–7.60) genes were not associated with damage, while the dupA gene was associated significantly with non-severe clinical outcome (p = 0.0032; OR = 0.25; 95% CI 0.09–0.65). In addition, dupA gene exerts protection against severe gastric pathologies induced by vacAi1 by delaying the outcome of the disease by approximately 20 years.  相似文献   

6.
Arbutoid mycorrhizas of Comarostaphylis arbutoides (Arbutoidea, Ericaceae) from neotropical montane forests are rarely described. To date, only mycorrhizal associations with the fungal species Leccinum monticola, Leotia lubrica and Sebacina sp. are known from literature. The genus Cortinarius is one of the most species-rich ectomycorrhizal taxa with over 2000 assumed species. In this study, two sites in the Cordillera de Talamanca of Costa Rica were sampled, where Com. arbutoides is endemic and grows together with Quercus costaricensis. Using a combined method of rDNA sequence analysis and morphotyping, 33 sampled mycorrhizal systems of Cortinarius were assigned to the subgenera Dermocybe, Phlegmacium and Telamonia. Specific plant primers were used to identify the host plant. Here, we present the phylogenetic data of all found Cortinarii and describe four of the arbutoid mycorrhizal systems morphologically and anatomically.  相似文献   

7.
Many species of the butterfly genus Phengaris are regarded as endangered in many parts of their distribution. Several species are also widely distributed across northern China. Due to land use change and overgrazing, their habitats are declining and many patches have been lost. This paper investigates the distribution and habitats of the Chinese Phengaris species (of the subgenus Maculinea). Shrub-grassland near forests seem the most frequent habitat for Phengaris, while flat open grasslands are mostly over-grazed and thus survival for Phengaris butterflies there seems difficult. Throughout Europe, P. teleius is an endangered species, while there is still no information on its status in China. To improve the knowledge on the population ecology of P. teleius, its population structure, adult behaviour and movement were studied through mark–release–recapture methods in the Qinling Mountains of Taibai County. Eight grassland patches which were potentially suitable were found in the area in 2013. In total, 480 individuals (274 females) were marked, resulting in an overall recapture rate of 16 %. The average daily population size was 44 butterflies (±23 SD) during the adult flight period. Sixty-seven percent of the females and 38 % of the males moved less than 50 m, and 17 % of recaptured females and 38 % of males moved more than 200 m. The mean movement distance was 107 ± 177 m for males and 182 ± 122 m for females. The majority of the recaptures (86 %) were made within the patches, only a few individuals (14 %) moved between patches. Due to human disturbance and destruction, all of the eight potentially suitable patches are becoming smaller and increasingly isolated, thus these populations of P. teleius may face an increasing risk of extinction, which may well be a tip of the iceberg of habitat loss and fragmentation of P. teleius in Taibai County and possibly beyond. Hence we hope our initial study of P. teleius could have positive impacts on the conservation of Phengaris butterflies in China.  相似文献   

8.
Ectomycorrhizal (ECM) and ectendomycorrhizal fungal species associated with Pinus montezumae were recorded in 8 year-old trees established in microcosms and compared with those associated with 2 year-old trees, in order to determine their persistence over the long-term. Mycorrhizal root tips were morphologically and anatomically characterized and sequenced. The extension of extramatrical mycelium of ECM fungi with long exploration strategies was evaluated. In total, 11 mycorrhizal species were registered. Seven mycorrhizal species were detected on both 2 and 8 year-old pines: Atheliaceae sp., Rhizopogon aff. fallax, R. aff. occidentalis, Suillus pseudobrevipes, Tuber separans, Wilcoxina mikolae and Wilcoxina rehmii. One species, Thelephora terrestris, was exclusively associated with two year–old seedlings, while Cenococcum geophilum, Pezizaceae sp. and Pyrenomataceae sp. were exclusively found on 8 year-old trees. Atheliaceae sp. was the ECM fungal species that presented the most abundant mycelium. Finally, we report one new fungal species of Pezizaceae occurring as a symbiont of P. montezumae.  相似文献   

9.
Hybridization between alien and native species is biologically very important and could lead to genetic erosion of native taxa. Solidago × niederederi was discovered over a century ago in Austria and described by Khek as a natural hybrid between the alien (nowadays regarded also as invasive) S. canadensis and native S. virgaurea. Although interspecific hybridization in the genus Solidago is considered to be relatively common, hybrid nature of S. × niederederi has not been independently proven using molecular tools, to date. Because proper identification of the parentage for the hybrid Solidago individuals solely based on morphological features can be misleading, in this paper we report an additive polymorphism pattern expressed in the ITS sequences obtained from individuals representing S. × niederederi, and confirm the previous hypothesis that the parental species of this hybrid are S. canadensis and S. virgaurea. Additionally, based on variability at the cpDNA rpl32-trnL locus, we showed that in natural populations hybridization occurs in both directions.  相似文献   

10.
The potential of endophytic bacteria to act as biofertilizers and bioprotectants has been demonstrated, and considerable progress has been made in explaining their role in plant protection. In the present study, three endophytic bacterial strains (BHU 12, BHU 16 isolated from the leaves of Abelmoschus esculentus, and BHU M7 isolated from the leaves of Andrographis paniculata) were used which displayed high sequence similarity to Alcaligenes faecalis. The biofilm formation ability of these endophytic strains in the presence of okra root exudates confirms their chemotactic ability, an initial step for successful endophytic colonization. Further, reinoculation of spontaneous rifampicin-tagged mutants into okra seedlings revealed a CFU count above 105 cells g?1 of all three endophytic strains in root samples during the first 15 days of plant growth. The CFU count increased up to 1013 by 30 days of plant growth, followed by a gradual decline to approximately 1010 cells g?1 at 45 days of plant growth. Systemic endophytic colonization was further supported by 2, 3, 5-triphenyl tetrazolium chloride staining and fluorescence imaging of ds-RED expressing conjugants of the endophytic strains. The strains were further assessed for their plausible in vivo and in vitro plant growth-promoting and antagonistic abilities. Our results demonstrated that the endophytic strains BHU 12, BHU 16, and BHU M7 augmented plant biomass by greater than 40 %. Root and shoot lengths of okra plants when primed by BHU 12, BHU 16, and BHU M7 increased up to 34 and 14.5 %, respectively. The endophytic isolates also exhibited significant in vitro antagonistic potential against the collar rot pathogen Sclerotium rolfsii. In summary, our results demonstrate excellent potential of the three endophytic bacterial strains as biofertilizers and biocontrol agents, indicating the possibility for use in sustainable agriculture.  相似文献   

11.
Three hundred and sixty presumptive lactic acid bacteria (LAB) isolated from pregnant sows, newborn, suckling, and weaned piglets were preliminarily screened for anti-Salmonella activity. Fifty-eight isolates consisting of Lactobacillus reuteri (n = 32), Lactobacillus salivarius (n = 10), Lactobacillus mucosae (n = 8), Lactobacillus johnsonii (n = 5), and Lactobacillus crispatus (n = 3) were selected and further characterized for probiotic properties including production of antimicrobial substances, acid and bile tolerance, and cell adherence to Caco-2 cells. Eight isolates including Lact. johnsonii LJ202 and Lact. reuteri LR108 were identified as potential probiotics. LJ202 was selected for further use in co-culture studies of two-bacterial and multiple-bacterial species to examine its inhibitory activity against Salmonella enterica serovar Enteritidis DMST7106 (SE7106). Co-culture of LJ202 and SE7106 showed that LJ202 could completely inhibit the growth of SE7106 in 10 h of co-culture. In co-culture of multiple-bacterial species, culturable fecal bacteria from pig feces were used as representative of multiple-bacterial species. The study was performed to examine whether interactions among multiple-bacterial species would influence antagonistic activity of LJ202 against SE7106 and fecal coliform bacteria. Co-culture of SE7106 with different combinations of fecal bacteria and probiotic (LJ202 and LR108) or non-probiotic (Lact. mucosae LM303) strains revealed that the growth of SE7106 was completely inhibited either in the presence or in the absence of probiotic strains. Intriguingly, LJ202 exhibited notable inhibitory activity against fecal coliform bacteria while LR108 did not. Taken together, the results of co-culture studies suggested that LJ202 is a good probiotic candidate for further study its inhibitory effects against pathogen infections in pigs.  相似文献   

12.
We aimed to study MLH1 and MGMT methylation status in Helicobacter pylori-associated chronic gastritis in Egyptian patients with and without gastric cancer. 39 patients were included in our study. They were divided into 2 groups; patients without (group I) and with gastric adenocarcinoma (group II). Patients were subjected to clinical examination, abdominal ultrasound and upper endoscopy for gastric biopsy. Biopsies were subjected to urease test, histological examination, and DNA purification. H. pylori, Braf, Kras, MLH1 and MGMT methylation were assessed by quantitative PCR. DNA sequencing was performed to assess Braf and Kras genes mutation. qPCR of H. pylori was significantly higher in patients with adenocarcinoma (group II) than those without adenocarcinoma (group I); with a p < 0.001 as well as in patients with age above 50 years with a p value = 0.008. By applying logistic regression analysis it was reported that the H. pylori qPCR is a significant predictor to the adenocarcinoma with OR = 1.025 (95 % CI: 1. 002–1.048), with sensitivity of 90 % and specificity of 100 %. Adenocarcinoma patients had a significantly higher mean age and levels of H. Pylori, Braf, K-ras, methylated MGMT and methylated MLH1 than those of gastritis patients. DNA sequence analysis of Braf (codon 12) and Kras (codon 600) had genes mutation in gastric adenocarcinoma versus chronic gastritis. Conclusion: H. pylori may cause epigenetic changes predisposing the patients to cancer stomach. Estimation of H. pylori by qPCR can be a good predictor to adenocarcinoma. Braf and Kras genes mutation were reveled in gastritis and adenocarcinoma patients.  相似文献   

13.
Molecular markers derived from the complete chloroplast genome can provide effective tools for species identification and phylogenetic resolution. Complete chloroplast (cp) genome sequences of Capsicum species have been reported. We herein report the complete chloroplast genome sequence of Capsicum baccatum var. baccatum, a wild Capsicum species. The total length of the chloroplast genome is 157,145 bp with 37.7 % overall GC content. One pair of inverted repeats, 25,910 bp in length, was separated by a small single-copy region (17,974 bp) and large single-copy region (87,351 bp). This region contains 86 protein-coding genes, 30 tRNA genes, 4 rRNA genes, and 11 genes contain one or two introns. Pair-wise alignments of chloroplast genome were performed for genome-wide comparison. Analysis revealed a total of 134 simple sequence repeat (SSR) motifs and 282 insertions or deletions variants in the C. baccatum var. baccatum cp genome. The types and abundances of repeat units in Capsicum species were relatively conserved, and these loci could be used in future studies to investigate and conserve the genetic diversity of the Capsicum species.  相似文献   

14.
We examined differences in fine root morphology, mycorrhizal colonisation and root-inhabiting fungal communities between Picea abies individuals infected by Heterobasidion root-rot compared with healthy individuals in four stands on peat soils in Latvia. We hypothesised that decreased tree vitality and alteration in supply of photosynthates belowground due to root-rot infection might lead to changes in fungal communities of tree roots. Plots were established in places where trees were infected and in places where they were healthy. Within each stand, five replicate soil cores with roots were taken to 20 cm depth in each root-rot infected and uninfected plot. Root morphological parameters, mycorrhizal colonisation and associated fungal communities, and soil chemical properties were analysed. In three stands root morphological parameters and in all stands root mycorrhizal colonisation were similar between root-rot infected and uninfected plots. In one stand, there were significant differences in root morphological parameters between root-rot infected versus uninfected plots, but these were likely due to significant differences in soil chemical properties between the plots. Sequencing of the internal transcribed spacer of fungal nuclear rDNA from ectomycorrhizal (ECM) root morphotypes of P. abies revealed the presence of 42 fungal species, among which ECM basidiomycetes Tylospora asterophora (24.6 % of fine roots examined), Amphinema byssoides (14.5 %) and Russula sapinea (9.7 %) were most common. Within each stand, the richness of fungal species and the composition of fungal communities in root-rot infected versus uninfected plots were similar. In conclusion, Heterobasidion root-rot had little or no effect on fine root morphology, mycorrhizal colonisation and composition of fungal communities in fine roots of P. abies growing on peat soils.  相似文献   

15.
In vitro culture and genetic transformation of black gram are difficult due to its recalcitrant nature. Establishment of gene transfer procedure is a prerequisite to develop transgenic plants of black gram in a shorter period. Therefore, genetic transformation was performed to optimize the factors influencing transformation efficiency through Agrobacterium tumefaciens-mediated in planta transformation using EHA 105 strain harbouring reporter gene, bar, and selectable marker, gfp-gus, in sprouted half-seed explants of black gram. Several parameters, such as co-cultivation, acetosyringone concentration, exposure time to sonication, and vacuum infiltration influencing in planta transformation, have been evaluated in this study. The half-seed explants when sonicated for 3 min and vacuum infiltered for 2 min at 100 mm of Hg in the presence of A. tumefaciens (pCAMBIA1304 bar) suspensions and incubated for 3 days co-cultivation in MS medium with 100 µM acetosyringone showed maximum transformation efficiency (46 %). The putative transformants were selected by inoculating co-cultivated seeds in BASTA® (4 mg l?1) containing MS medium followed by BASTA® foliar spray on 15-day-old black gram plants (35 mg l?1) in green house, and the transgene integration was confirmed by biochemical assay (GUS), Polymerase chain reaction, Dot-blot, and Southern hybridisation analyses.  相似文献   

16.
Gut bacterium Pantoea sp. is one of the predominant bacterial species in the larval gut of the diamondback moth, Plutella xylostella. The phenotypic characters of Pantoea sp. were investigated with BIOLOG phenotype MicroArray (PM) in this study. Totally 950 different metabolic phenotypes were tested using the PM plates 1–10. Results exhibited that Pantoea sp. was able to metabolize 37.37 % of the tested carbon sources, 91.32 % of nitrogen sources, 100 % of sulfur sources, and 98.31 % of phosphorus sources. Most informative utilization patterns for carbon sources of Pantoea sp. were organic acids and carbohydrates, and for nitrogen were various amino acids. The bacterium had 94 different biosynthetic pathways. It had a wide range of adaptabilities, and could still metabolize in osmolytes with up to 9 % sodium chloride, 6 % potassium chloride, 5 % sodium sulfate, 20 % ethylene glycol, 4 % sodium formate, 4 % urea, 5 % sodium lactate, 200 mmol/L sodium phosphate (pH 7.0), 100 mmol/L ammonium sulfate (pH 8.0), 100 mmol/L sodium nitrate, and 100 mmol/L sodium nitrite, respectively. It also exhibited active metabolism under pH values between 4.5 and 10. Pantoea sp. showed active decarboxylase activities while poor deaminase activities in the presence of various amino acids. The phenotypic characterization of Pantoea sp. increased our knowledge of the bacterium, in particular its interactions with insect hosts and the adaptability in gut environments, and showed us some possible approaches to controlling diamondback moth through decreasing Pantoea sp. density.  相似文献   

17.
Plectosphaerella cucumerina (Lindf.) W. Gams was evaluated as a bioherbicide for Cirsium arvense L. (Scop.) using a Canadian and a New Zealand isolate. Both isolates defoliated C. arvense when applied at 1013 conidia ha?1 in water volumes ranging from 250 to 6400 l ha?1 with a rapid decline in effect with declining conidial dose. Repeat application and the addition of the adjuvant Pulse® penetrant to the conidial suspension increased the disease severity in C. arvense. Maximum disease occurred at 20 °C with a 48 h post-application dew period. The experiments demonstrate that P. cucumerina can defoliate C. arvense under the environmental conditions of temperate pastures where the weed is problematic. The results also show that modifications to formulation and strategic application may reduce the 48 h dew period requirement and risk to non-target species respectively, supporting the conclusion that the fungus has potential as a bioherbicide for C. arvense.  相似文献   

18.
Klebsiella pneumoniae is a 2,3-butanediol producer, and R-acetoin is an intermediate of 2,3-butanediol production. R-acetoin accumulation and dissimilation in K. pneumoniae was studied here. A budC mutant, which has lost 2,3-butanediol dehydrogenase activity, accumulated high levels of R-acetoin in culture broth. However, after glucose was exhausted, the accumulated R-acetoin could be reused by the cells as a carbon source. Acetoin dehydrogenase enzyme system, encoded by acoABCD, was responsible for R-acetoin dissimilation. acoABCD mutants lost the ability to grow on acetoin as the sole carbon source, and the acetoin accumulated could not be dissimilated. However, in the presence of another carbon source, the acetoin accumulated in broth of acoABCD mutants was converted to 2,3-butanediol. Parameters of R-acetoin production by budC mutants were optimized in batch culture. Aerobic culture and mildly acidic conditions (pH 6–6.5) favored R-acetoin accumulation. At the optimized conditions, in fed-batch fermentation, 62.3 g/L R-acetoin was produced by budC and acoABCD double mutant in 57 h culture, with an optical purity of 98.0 %, and a substrate conversion ratio of 28.7 %.  相似文献   

19.
Global warming is affecting Mediterranean ecosystems, in which Arbutus unedo represents an important species. Mesophyll protoplasts are convenient material to study plant DNA integrity, nevertheless their release from mature plants along the year has not been reported in sclerophyll species. In this respect, in the present study the chance to isolate protoplasts from leaf tissues of A. unedo in different seasons was investigated. The digestion was obtained using Macerozyme R10 (1%) and Cellulase Onozuka RS (2%), with 0.6 M of mannitol, incubated for 4 h at 25 °C in the dark. In spring, soft leaves of different ages were studied to identify the most suitable material and protoplast yields were significantly influenced, with the still expanding 4th leaf characterized by the highest amount. Protoplast release decreased during the growing season when leaves become partially hardened, while their obtainment was quite impossible in summer and winter, due to leaf hardening. In November, an increase of incubation time (16 h) and of Cellulase RS (4%) or mannitol concentration (0.8 M) was needed with chilled leaves from the field; conversely, a good source for protoplasts were the green soft leaves coming from detached and pruned branches placed in controlled environment at spring temperatures. The employment of polyvinylpyrrolidone-40 during isolation procedure is discussed. The isolated protoplasts were employed to assess the DNA integrity, by using single cell gel electrophoresis (SCGE). The X-irradiated nucleoids were significantly damaged confirming that the present approach could be used in the selection of elite material of A. unedo devoted to fruit plantation.  相似文献   

20.
Cajanus platycarpus, a wild relative of Cajanus cajan, is an important source for various agronomically desirable traits, including resistance towards pod borer, Helicoverpa armigera. In the present study, the inhibitory activity of proteinase inhibitors (PIs) present in crude protein extracted from different accessions of C. platycarpus and cultivars of C. cajan was evaluated against H. armigera under in vitro and in vivo conditions. The PIs active against H. armigera gut trypsin-like proteinases (HGPs), referred to as ‘HGPIs’, were more pronounced in mature dry seeds of C. platycarpus accessions when compared with cultivars, which is also evident through gelatin activity staining studies. Therefore, the inhibitory activity of HGPIs was further evaluated in various plant organs of C. platycarpus accessions, such as leaves, flowers, pods, developing seeds at 8–10 days (DAP-I), 18–20 days (DAP-II), and 28–32 days after pollination (DAP-III). However, the HGPI activity was more pronounced in mature dry seeds > DAP-III > DAP-II > DAP-I > flowers > pods > leaves. The observed quantitative allocation of HGPIs closely resembled “Optimal Defense Theory”. Further, bioassays demonstrated that there was a significant reduction in the body weight of the larvae fed upon crude PI extracts of C. platycarpus accessions with concomitant increase in mortality rate and the formation of larval–pupal intermediates. Nevertheless, such changes were not observed when the larvae were fed on crude PI extracts of C. cajan cultivars. These results suggest that the PI gene(s) from C. platycarpus accessions could be exploited in the management of H. armigera by introgression into C. cajan cultivars.  相似文献   

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