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31.
Summary Over 7,600 durum wheat accessions belonging to 22 country gene pools were evaluated in Syria, during the seasons 1985–86 through 1987–88 under semi-arid Mediterranean climatic conditions. Data on seven agronomic traits are presented to assess the distinctiveness and the phenotypic diversity of these pools. Univariate statistical analysis revealed differences among materials of diverse origins for all traits. Mean phenotypic diversity within countries was highest in the germplasm from India, lowest in that from Bulgaria. In a canonical variate analysis, the first three canonical variables explained 77.7% of the total variance. A cluster analysis was performed to supplement the generated information by the canonical analysis. The multivariate analyses evidenced the distinctiveness of the Ethiopian germplasm. The gene pools from Syria and Jordan, closely resembling each other, appeared separate from all others. A certain peculiarity was also shown by the germplasms from Greece, Morocco and France, while the remaining countries clustered into four groups. The results of the present evaluation could provide useful information for breeding activities, germplasm collection, and establishment of core collections. Evidence is presented that environment played a major role in creating the overall variation for the considered traits, although germplasm exchange seemed also an important factor.  相似文献   
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Paolo Ranalli 《Euphytica》1996,87(2):127-132
Summary The effect of a recurrent selection procedure for improving seed yield per plant was evaluated in common bean. Progress was registered after three cycles of recurrent selection with S2 progeny evaluation performed on the grain yield/plant. Gain from selection was estimated by field testing 45 random S2 lines from each of the C0, C1 and C2 populations. Response to selection for seed yield/plant was 6 g from C0 to C1 and 4.4 g from C1 to C2. The seed yield improvement was due principally to an increase in pods/plant; little contribution was provided by the 1000-seed weight and seeds/pod traits. Broad-sense heritability and genotypic variance for grain yield remained high in all cycles which suggests further gain from additional selection cycles. Grain yield/plant is significantly correlated to pods/plant and seeds/pod traits in all cycles, indicating that plants with favourable combinations of these traits could be identified. The proposed recurrent selection procedure appears to be effective in improving the population and extracting superior genotypes for varietal development.  相似文献   
34.
Paolo Annicchiarico 《Euphytica》1993,71(1-2):131-141
Summary A set of Ladino white clover ecotypes including the last available landraces and some natural populations collected from old permanent meadows, together with some white clover varieties of various origins, were evaluated as monocultures for dry matter (DM) and seed yield assessed in separate field experiments. Other agronomic traits were also recorded. The best performing variety, Espanso, was significantly outyielded by some ecotypes for DM and seed production. Compared to landraces, natural populations yielded on average far less seed but as much DM and tended towards higher persistence indicating that domestication of the native Ladino at the farm level only improved seed yield of the crop. Natural populations showed, besides lower values of most seed yield components, a distinct canopy architecture characterized by smaller leaves, longer internodes and denser stolons. Seed weight proved the best character discriminating between the two ecotype groups. Significant variation for most traits was found both among landraces, in which it was mostly relatable to differences among provenances, and among natural populations. The relations between the main multivariate patterns of phenotypic variation and a set of environment collecting variables suggested that evolutive adaptation to different agronomic practices was a major determinant of the overall variation found in landraces. Evidence is provided that a relevant part of the variation observed among ecotypes for some important traits could be genetic.Abbreviations DM dry matter - DMY dry matter yield - NRH number of ripe heads - NFH number of florets per head - PL petiole length - LS leaf size - IL internode length - NS number of stolons - PRO protein content - SY seed yield - TSW thousand seed weight - NSF number of seeds per floret - PCA principal components analysis - PC principal component  相似文献   
35.
The composition of the essential oil from ripe and unripe berries and leaves of Juniperus oxycedrus L. ssp. oxycedrus, Juniperus phoenicea ssp. turbinata and Juniperus communis ssp. communis was analyzed by GC-MS, and microbiological assays were carried out. Samples were collected in different localities (Sardinia, Italy) and hydro distilled. The yields ranged between 2.54% +/- 0.21 (v\w dried weight) and 0.04% +/- 0.00. A total of 36 components were identified. The major compounds in the essential oils were alpha-pinene, beta-pinene, delta-3-carene, sabinene, myrcene, beta-phellandrene, limonene, and D-germacrene. Both qualitative and quantitative differences between species and between different parts of the plant were observed. The essential oils and their major compounds were tested against Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and the minimum inhibitory concentration and minimum bactericidal concentration were determined. The results obtained led to a nonsignificant inhibitory effect, although all the essential oils from Juniperus phoenicea ssp. turbinata and the essential oil from leaves of Juniperus oxycedrus ssp. oxycedrus exhibited rather good or weak activity against Candida albicans and Staphylococcus aureus.  相似文献   
36.
In this work an HPLC method for the determination of azadirachtin residues on olives was developed, and the field degradation kinetics of the pesticide was studied. In field trials the active ingredient (a.i.) decay had a half-life time of 0.8 days, which was too short to show a good efficacy of treatment. The mechanism of disappearance of the pesticide studied with model systems showed that it was unrelated to evaporation, thermodegradation, and co-distillation, but it was related to photodegradation. The high photodegradation rate of commercial formulations calls for the need to test different formulates in order to increase the persistence of the residue and thus the pesticide's efficacy.  相似文献   
37.
This study compares the detection of faecal contamination indicators in irrigation water (25 samples) by two analytical techniques: multiple tube fermentation method (MPN) and Colilert/Enterolert Quanti-Tray system. Our aim was to investigate variations in the test results and determine whether variations could be related to 1) the interval of time between the sample collection and analysis and 2) the manual labour of the operator. Each water sample was analysed at specific intervals of time from the sample collection within 24 h and by three different operators. Statistical analysis was employed to evaluate the results. We have proved that the indices obtained with the multiple tube fermentation method show greater variation than the values obtained with the Colilert and Enterolert systems. Furthermore, some samples, analysed by the MPN method, showed different values, but not statistically significant, in relation to the intervals of time between the sample collection and analysis and in relation to the data obtained by the manual labour of the operators. Values for the same sample varied in respect to legislative limits. The Colilert and Enterolert systems for the detection of indicator bacteria could be a substitute for the standard methods. This procedure could be used for monitoring the quality of irrigation water.  相似文献   
38.
A lupin seed γ-conglutin-enriched preparation was tested in a glucose overload trial with both murine models and adult healthy volunteers. The results with rats showed a dose-dependent significant decrease of blood glucose concentration, which confirmed previous findings obtained with the purified protein. Moreover, three test-product doses equivalent to 630, 315, and 157.5 mg γ-conglutin, orally administered 30 min before the carbohydrate supply, showed a relevant hypoglycemic effect in human trials. Insulin concentrations were not significantly affected. The general hematic parameters did not change at all.This is the first report on the glucose-lowering effect of lupin γ-conglutin in human subjects.  相似文献   
39.
The aim of this work was to develop a method for authenticity control of organically grown orange fruits. Due to the different kinds of nitrogen fertilization of the soil in organically and conventionally managed farms, the study tried to verify the possibility to differentiate Navelina and Tarocco orange fruits obtained by these production systems through the detection of markers linked to nitrogen metabolism. In addition to the classic quality parameters, total nitrogen (N) and synephrine contents in juice and (15)N/(14)N isotope ratio (expressed as delta(15)N per thousand) in proteins of pulp and amino acids of juice were determined. The results obtained indicated that total N and synephrine contents were significantly higher in conventional fruits, whereas the delta(15)N per thousand values were higher in the organic ones. The new markers identified in this research by linear discriminant analysis of the data may constitute a useful tool to differentiate organic citrus fruits or juices from conventional ones.  相似文献   
40.
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