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ABSTRACT The complete nucleotide (nt) sequences of the cloned DNA-A (2644 nts) and DNA-B (2609 nts) components of Bean golden yellow mosaic virus (BGYMV-MX) from Chiapas, Mexico were determined. The genome organization of BGYMV-MX is similar to that of other Western Hemisphere bipartite geminiviruses (genus Begomovirus). Infectivity of the cloned BGYMV-MX DNA components in common bean (Phaseolus vulgaris) plants was demonstrated by particle bombardment and agroinoculation. BGYMV-MX was identified as a BGYMV (previously type II BGMV) isolate based on sequence analyses, sap-transmissibility, and pseudorecombination experiments with other bean-infecting begomoviruses. On the basis of differences in the DNA-B hypervariable region, symptom phenotype, and properties of infectious pseudorecombinants, BGYMV-MX may represent a distinct strain of BGYMV. Pseudorecombination experiments further established that BGYMV symptom determinants mapped to DNA-B, and that BGYMV-MX was most closely related to BGYMV from Guatemala. A Tomato leaf crumple virus (TLCrV) DNA-A/BGYMV-MX DNA-B pseudorecombinant was infectious in bean, establishing that a viable reassortant can be formed between begomovirus species from different phylogenetic clusters. Bean germ plasm representing the two major gene pools (Andean and Mesoamerican) was screened for response to BGYMV-MX with three methods of inoculation: sap-inoculation, particle bombardment, and agroinoculation. Andean germ plasm was very susceptible and similar results were obtained with all three methods, whereas Mesoamerican germ plasm showed resistance to BGYMV-MX, particularly with agroinoculation. 相似文献
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Lani E. Yakabe M. Malendia Maccree Padma Sudarshana Ali E. McClean Shane R. Parker William P. Wechter Gernot Presting Mizuri Marutani-Hert Daniel A. Kluepfel 《Journal of General Plant Pathology》2012,78(2):121-126
Novel PCR primers were developed to amplify a 243-bp fragment of an intergenic region between gene 5 and tms2 on the T-DNA of Agrobacterium tumefaciens biovar 1. These primers exhibit 100% positive correlation with strain virulence, 100% negative correlation with avirulence, and did
not generate extraneous bands, thus facilitating robust real-time PCR detection. 相似文献
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Displacement of native rhizobia nodulating chickpea (Cicer arietinum L.) by an inoculant strain through soil solarization 总被引：1，自引：0，他引：1
Summary Soil solarization greatly reduced the native chickpea Rhizobium population. With inoculation, it was possible to increase the population of the Rhizobium in solarized plots. In the 1st year, 47% nodulation was obtained with chickpea inoculant strain IC 59 when introduced with a cereal crop 2 weeks after the soil solarization and having a native Rhizobium count of <10 g-1 soil, and only 13% when introduced 16 weeks after solarization at the time the chickpeas were sown, with 2.0×102 native rhizobia g-1 soil. In the non-solarized plots inoculated with 5.6×103 native rhizobia g-1 soil, only 6% nodulation was obtained with the inoculant. In the succeeding year, non-inoculated chickpea was grown on the same plots without any solarization or Rhizobium inoculation. The treatment that showed good establishment of the inoculant strain in year 1 formed 68% inoculant nodules. Other treatments indicated a further reduction in inoculant success, from 1%–13% to 1%–9%. Soil solarization thus allowed an inoculant strain to successfully displace the high native population in the field and can serve as a research tool to compare strains in the field, irrespective of competitive ability. In year 1, Rhizobium inoculation of chickpea gave increased nodulation and increased plant growth 20 and 51 days after sowing, and increased dry matter, grain yield, and grain protein yield at maturity. These beneficial effects of inoculation on plant growth and yield were not measured in the 2nd year.Submitted as Journal Article No. JA 945 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh 502 324, India 相似文献
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Khanum F Anilakumar KR Sudarshana Krishna KR Viswanathan KR Santhanam K 《Plant foods for human nutrition (Dordrecht, Netherlands)》2000,55(4):347-355
Curry leaves are one of the spices used in Indian dishes for aroma and preservation. There are no reports on the antioxidant properties of curry leaves. In this study, the antioxidant potential of curry leaves in rats treated with a known chemical carcinogen, dimethylhydrazine hydrochloride (DMH) was investigated. Food intake was reduced in the rats fed curry leaf-supplemented diet but the body and the organ weights were not affected.Vitamin A content in the liver was significantly increased whereas glutathione (GSH) content was not altered. A 50% reduction was seen in the micronuclei induced by DMH and a 30% reduction in the activity of ,-glutamyl transpeptidase when the rats were fed a curry leaf-supplemented diet. These results indicate that curry leaves have highpotential as reducer of the toxicity of DMH. 相似文献
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Ali E. McClean Padma Sudarshana Daniel A. Kluepfel 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(3):413-424
Deep bark canker (DBC) of walnut is caused by the bacterium Brenneria rubrifaciens which produces the red pigment rubrifacine. This disease of English walnut trees, is characterized by deep vertical cankers
which exude sap laden with B. rubrifaciens. Although DBC is not observed on young trees, it is hypothesized that B. rubrifaciens is present in host tissue years before symptom development. Therefore, a sensitive technique would be useful in detecting
B. rubrifaciens in asymptomatic trees. Tn5 mutants deficient in rubrifacine production (pig
−) were generated and DNA sequences from pig
− mutants were used to design two primer sets; GSP1F–GSP1R and GSP2F–GSP2R. A third primer pair, BR1–BR3 was designed from
the 16S rRNA gene. The three primer pairs did not amplify the diagnostic bands from members of the following bacterial genera:
Agrobacterium, Erwinia, Pseudomonas, Ralstonia, and Rhizobium. In addition, no amplification was observed using DNA from the following Brenneria species, alni, nigrifluens, quercina, or salicis. All three DNA primer sets detected B. rubrifaciens in spiked greenhouse soil and infiltrated walnut leaf tissue. PCR detection limits for BR, GSP1, and GSP2 primer pairs were
254, 254, and 2.54 × 104 colony forming units (CFU) respectively. Real-time PCR detection limit for BR primers was 8 CFU. The differential medium,
yeast extract dextrose calcium carbonate agar (YDCA) was amended with novobiocin, and bacitracin, to enhance isolation from
environmental samples. The improved detection and isolation methods described here will facilitate examination of B. rubrifaciens ecology under both nursery and orchard conditions. 相似文献
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Khanum F Siddalinga Swamy M Sudarshana Krishna KR Santhanam K Viswanathan KR 《Plant foods for human nutrition (Dordrecht, Netherlands)》2000,55(3):207-218
Legumes, leafy vegetables,roots and tubers, gourds and other vegetables were analyzed for total (TDF), soluble (SDF) and insoluble (IDF) dietaryfiber contents, both before and after cooking eitherby a conventional open-pan method or by pressurecooker. Data revealed a significant increase inSDF fraction with a concomitant decrease in the IDFfraction upon cooking by both the methods employed. Although the decrease in IDF matched the increase inSDF values in some cases, it was found to be more invegetables categorized as `other'. The dietary fiber values have also been reported on a fresh weight basis which may serve as a guideline for calculating dietary intake of eachcomponent by the consumer. 相似文献
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K. E. Giller M. R. Sudarshana J. A. Thompson O. P. Rupela 《Biology and Fertility of Soils》1988,6(4):347-351
Summary N accumulation, nodulation, and acetylene reduction activity were measured at frequent intervals during the growth of two chickpea genotypes, and N2 fixation was estimated by an isotope-dilution method, using safflower as a non-N2-fixing reference. Safflower was more efficient at N uptake than both the chickpea genotypes for at least the first 50 days and thus could not be used as an accurate reference control. We recommend that further work should employ non-nodulatiog genotypes of chickpea as reference plants and use slow-release forms of 15N fertilizer. Direct genotype comparison by isotope dilution estimated that genotype K 850 fixed 16–18 kg ha–1 more N than G 130, and this difference was supported by the greater nodule mass and acetylene reduction activity in the K 850 cultivar. Inoculation with an ineffective chickpea Rhizobium sp. led to 69% nodulation on cultivar K 850 but only 33% on G 130. While nodule weight, N uptake, and acetylene reduction activity decreased with inoculation in K 850, the isotope dilutions were similar for both inoculation treatments. The lack of a significant effect on N2 fixation was ascribed to the partial success of inoculant establishment.Published as Journal Article No. JA 692 of the International Crops Research Institute for the Semi Arid Tropics, Patancheru, A.P. 502324, India 相似文献
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