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41.
When detached broad bean leaves were preinoculated with virulent strain B304 of Botrytis cinerea 24 h before a challenge inoculation with strain B304, lesion formation by B304 was significantly inhibited in red light but not in the dark. In leaves that were preinoculated with avirulent strain 021 and then challenged by B304, however, lesion formation was not inhibited even under red light. Such differences in lesion formation after the challenge inoculation with an avirulent strain were also observed with lesions caused by Alternaria alternata, a nonpathogen of broad bean and by avirulent strain 021R in the presence of germination fluid from spores of strains B304 and 021R. These results suggest the possibility that virulent B. cinerea produced a suppressor involved in induced susceptibility and an elicitor involved in resistance induced by red light during spore germination.  相似文献   
42.
43.
There are many reports on the effect of arginine on the growth of cultivated tissues or organs. Arginine usually enhances the growth of tissues and organs (1-9).  相似文献   
44.
It has generally been accepted that humus and its C/N ratio decrease with the depth of soil profile.  相似文献   
45.
Floral scent attracts pollinators. We investigated the floral scent compounds recognized by pollinators in six Brassica crop species, including allogamous species with different genomes and autogamous species with two parental genomes and radish (Raphanus sativus). Biologically active compounds recognized by honeybees were screened from all floral compounds by combined gas chromatography–electroantennogram analysis and their profiles were determined by gas chromatography–mass spectrometry. Fourteen of the 52 compounds were active. All accessions had more than two active compounds, but the compounds greatly differed between the two genera. On the basis of similarities in whether active compounds were presence or absence, their amount and their composition ratio, we divided the Brassica accessions into three to five groups by cluster analyses. Most groups were composed of a mixture of allogamous and autogamous species sharing same genome, indicating that the variation depended on genome, not species. These results suggest that all species require pollinator visits for reproduction, despite their different reproductive systems. However, the inter-genus and intra-specific variations shown by the multiple groups within a species might cause different visitation frequencies by pollinators between genera and among accessions within a species, resulting in insufficient seed production in some accessions or species.  相似文献   
46.
Seed saponin composition of 3025 wild soybean (Glycine soja Sieb. and Zucc.) accessions collected from nine regions of Korea was analysed by thin‐layer chromatography to determine its polymorphic variation and geographical distribution and find mutants in saponin components. The saponin composition of seed hypocotyls was primarily divided into seven phenotypes, designated as Aa, Ab, AaBc, AbBc, Aa+α, AaBc+α and AbBc+α. The predominant phenotypes were AaBc (55%), Aa (33%), AaBc+α (7.5%) and Aa+α (3.3%). The frequencies of Ab, AbBc and AbBc+α were very low (0.3‐0.5%). Codominant alleles Sg‐1a and Sg‐1b and dominant allele Sg‐4 occupied 98.6, 1.1 and 63.3%, respectively. Alleles Sg‐3 and Sg‐5 were found to be dominant in all the analysed accessions except the mutants. Three accessions were discovered as mutants via LC‐PDA/MS/MS. The accession CWS0115 did not produce saponin Aa and Ax, CWS2133 did not produce saponin Aa and Ab and CWS5095 did not produce any group A saponins. These newly determined mutants might be utilized in producing a new soybean variety with good taste as well as in biosynthetic studies.  相似文献   
47.
Simultaneous determination of all polyphenols in vegetables,fruits, and teas   总被引:10,自引:0,他引:10  
Polyphenols, which have beneficial effects on health and occur ubiquitously in plant foods, are extremely diverse. We developed a method for simultaneously determining all the polyphenols in foodstuffs, using HPLC and a photodiode array to construct a library comprising retention times, spectra of aglycons, and respective calibration curves for 100 standard chemicals. The food was homogenized in liquid nitrogen, lyophilized, extracted with 90% methanol, and subjected to HPLC without hydrolysis. The recovery was 68-92%, and the variation in reproducibility ranged between 1 and 9%. The HPLC eluted polyphenols with good resolution within 95 min in the following order: simple polyphenols, catechins, anthocyanins, glycosides of flavones, flavonols, isoflavones and flavanones, their aglycons, anthraquinones, chalcones, and theaflavins. All the polyphenols in 63 vegetables, fruits, and teas were then examined in terms of content and class. The present method offers accuracy by avoiding the decomposition of polyphenols during hydrolysis, the ability to determine aglycons separately from glycosides, and information on simple polyphenol levels simultaneously.  相似文献   
48.
Some physicochemical properties and molecular structures of starches from millet (Pennisetum typhoides, Doro and Gero) and sorghum (Sorghum bicolor, red and white) in Nigeria were examined. Starch granules of millet and sorghum were 3–14 μm and 4–26 μm in diameter, respectively. Millet cultivars had similar peak viscosities (204–205 RVU) on pasting, while sorghum showed similar minimum viscosities (155–156 RVU). The actual amylose content (%) calculated from iodine affinity (IA, g/100 g) was 20.1 and 21.4 for sorghum and 21.3 for millet. The IA of amylopectin was high (1.27–1.42) and its average chain lengths were 20–21 with β‐amylolysis limit of 56%. Amylopectins showed a polymodal molecular weight distribution on a molar basis. The distributions differed among the samples with a higher amount of larger molecules in Doro and red sorghum. Weight‐ and molar‐based distributions of debranched amylopectins on HPSEC were polymodal with weight‐based distribution showing presence of long chains. Peak DP values for A+B1 and B2+B3 chain fractions were 13–16 and 42–43, respectively. The (A+B1)/(B2+B3) ratio on molar basis (9.0–11.5) was similar to maize and rice amylopectins. Peak DP on molar‐based distribution for white sorghum and millet amyloses were similar (490–540) and the DPn range was narrow (1,060–1,300), but weight‐based distribution profiles differed. The average chain lengths were 260–270 with 3.9–4.8 chains per molecule.  相似文献   
49.
Nitrate leaching from agricultural lands is one of the most critical problems related to both environmental quality and human health. Although in many studies surfacecharge properties of and nitrate adsorption in soils have been analyzed in tropical and subtropical regions, fewer studies have been conducted on the nitrateretention properties of allo phanic Andisols. The objectives of the present study were to examine the potential nitrate adsorption capacity and the factors affecting nitrate retention in topsoils and subsoils of three Andisols Tokaachi, Hokkaido. Nitrate adsorption at pH 6.0 was found to be low or negligible even in the subsoil of a Haplic Wet Andisol (Melanaquands), despite the high clay content, Nitrate adsorption maxima calculated from the Langmuir equation were higher in the lower horizons of a Haplic Andisol (Melanudands) and a Lowhumic Andisol (Hap ludands), which were developed under moderate to moderately dry moisture conditions and displayed a high allophane content and a low total carbon content. The nitrate adsorption of the aliophanic Andisols was much higher than that reported from other studies conducted in Ultisols and Oxisols, which are rich in iron oxides. The potential capacity to adsorb nitrates and retard nitrate movement should be taken into account in predicting the fate of nitrate in soils and the consequent mitigation of groundwater contamination.  相似文献   
50.
The diversity of neonicotinoid insecticides acting as insect nicotinic acetylcholine (ACh) receptor (nAChR) agonists is illustrated by imidacloprid (IMI) with chloropyridinylmethyl (CPM) and N-nitroimine substituents, dinotefuran (DIN) with tetrahydrofurylmethyl (TFM) and N-nitroimine moieties, and acetamiprid (ACE) with CPM and N-cyanoimine groups. These three neonicotinoids are used here as radioligands to test the hypothesis that they all bind to the same site in the same way in both fruit flies (Drosophila melanogaster) and a leafhopper pest (Homalodisca coagulata): that is, neonicotinoid binding site specificity is conserved in the insect nAChRs. Multiple approaches show that [3H]IMI and [3H]ACE interact with an identical site in both species. However, although [3H]DIN binds with high affinity in both insects, its pharmacological profile in Homalodisca is surprisingly unique, with high sensitivity to some TFM-containing compounds and ACh. The TFM moiety of DIN may bind in a different orientation compared to the CPM group of IMI and ACE.  相似文献   
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