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91.
针对黄顶菊种子人工识别时存在的主观性强、效率低、可重复性差等缺点,提出利用计算机视觉和图像处理技术提取黄顶菊种子特征参数的方法,研究了黄顶菊种子图像的分割方法、目标提取及种子图像中形态和颜色特征的提取方法,分析了各形态特征参数的相关性,筛选出了能精确反映黄顶菊种子几何特征的参数,验证了各特征参数提取方法的有效性,为后期的种子自动识别提供了依据。 相似文献
92.
Early assessment of processing strawberries for colour 总被引:1,自引:0,他引:1
Hedley Williams 《Euphytica》1977,26(3):841-845
Summary It is possible to select strawberry cultivars that give a satisfactory, naturally coloured canned product as an alternative to the commercially dyed one. Spectrophotometric measurements of the syrup from cans, the canned fruit and fresh fruit were compared with visual scoring. A preliminary screening for colour based on visual assessment of fresh flesh colour is possible. 相似文献
93.
Summary The sensitivity of Fragaria seedlings to colchicine is dependent on the plant organ that is treated. Complete immersion of seedlings in a 1.5% colchicine solution results in total lethality, whereas the survival rates were more than 75% even at concentrations of 3.0% when only shoot apices were treated. High proportions of polyploids were isolated by treating shoot apices of seedlings with a 2.0% colchicine solution for 24–28 h. The dropper method is preferred to the tube method as it involves a minimum of manipulation and requires simple equipment. A differential response to colchicine was observed within and between different diploid species, diploid and tetraploid hybrids. 相似文献
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Petra Scheewe 《Euphytica》1994,77(1-2):25-29
Summary The fungusPhytophthora fragariae Hickman is the causal agent of red stele disease in strawberry (Fragaria × ananassa), this being a major disease in many areas with cool and moist conditions. Success of resistance breeding can be nullified
by the appearence of specific races of the fungus capable of overcoming the introduced resistance. In some countries (USA,
UK, Japan and Canada) races were identified by using a differential set of strawberry cultivars. The absence of an international
standard differential set and the use of different test methods make a comparison of the identified races difficult or even
lead to contradictory results for one variety/race combination. The aim of this study was to obtain information about the
spectrum of pathogenic races in Germany as a basic contribution to research on resistance breeding against the fungus. The
susceptibility of different strawberry cultivars to German isolates ofP. fragariae was evaluated. The inoculation was done by modifying a method described by Milholland et al. (1989). Rootedin vitro plants, four weeks after transferring them to the soil, were used for the investigation. Inoculation was done with a zoospore
suspension of defined concentration. Up to now three German isolates, G-1, G-2, and G-3, can be separated by their ability
to infect and produce oospores in the roots of the strawberry cultivars ‘Senga Sengana’, either ‘Saladin’, ‘Redgauntlet’ or
‘Climax’ andFragaria chiloensis clone ‘YaquinaB’. These results confirm the existence of pathogenic races ofP. fragariae in Germany and should be taken into consideration for resistance breeding against the fungus. 相似文献
96.
Effect of in vitro propagation methods on field performance of two strawberry cultivars 总被引:2,自引:0,他引:2
Summary Strawberry cultivars, Redcoat and Veestar, propagated by meristem culture (MC), callus culture (CC) and direct shoot regeneration (DR) from leaf disks were compared for their vegetative and reproductive characters with standard runner (SR) propagated plants under field conditions. In the planting year, in vitro propagated plants of both cultivars had the same number of leaves as SR plants, but in vitro propagated Redcoat produced fewer stolons per plant than SR plants. However, in the following year, in vitro propagated mother plants of both cultivars had more leaves and higher runner production than SR mother plants. Flowering and fruiting behaviour of Veestar was not appreciably influenced by in vitro propagation methods. However, in vitro propagated plants of Redcoat flowered earlier and produced more flowers and fruits than SR plants, but still maintained normal berry weight. Among in vitro propagated plants, DR plants of Redcoat were the earliest to flower, whereas MC plants produced more flowers and fruits. The field performance of the first daughter plants derived from the in vitro propagated plants was consistent with their respective mother plants. Leaf shape of both cultivars was not altered by in vitro propagation. Phenotypic abnormalities were mainly confined to occurrence of yellow leaf variants in MC and CC plants and occasional appearance of plants with irregular flowering and growth habit among CC plants.NRCC No. 38004 相似文献
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99.
A method using possibility theory and fuzzy logic is introduced. Possibility functions of each feature are determined during training. Methods of fuzzy logic are used to combine the possibility of different features. This Chinese character recognition system consists of a pre-classifier and a two-level fine classifier. In order to handle deviations of the characters,a fuzzification of features is introduced. This method is used to develop single-font classifiers. The whole system consists of a font-classifiers and four single-font-classifiers. 相似文献
100.
The learning algorithm of networks is discussed. The programming example of 3 layer BP networks is given with Visual C++6.0 program langue. Based on this model, a lung cancer intelligent diagnosis system is successfully implemented. Furthermore, the paper introduces network's structure design, preferencesand the source of stylebookdatum in factual applications. The ameliorative arithmetic is applied to the study of networks and BP dynamic evolving process is designed. The experiments indicatecell images are recognized and classified by the trained neural network. The study illustrates the system has feasibility and clinical value in lung cancer diagnosis. 相似文献