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Denis Rusjan Heidi Halbwirth Karl Stich Maja Mikuli?-Petkov?ek Robert Veberi? 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(2):231-237
This study was carried out on the leaves of phytoplasma susceptible grapevine variety ??Chardonnay?? (Vitis vinifera L.), and included research of the alterations in chlorophyll and carotenoid contents, contents of phenol compounds and in related enzymes activity in the phenylpropanoid pathway during the Bois noir (BN) infection. Phytoplasma-infected leaves showed reduced contents of chlorophylls and carotenoids, which promoted their susceptibility to oxidative reactions. Furthermore, modulation of flavonoid biosynthesis occurred in infected leaves, leading to an increased activity of phenylalanine ammonia lyase, chalcone synthase/chalcone isomerase, flavanone 3-hydroxylase and polyphenoloxidase, but to a decreased peroxidase activity. Phytoplasma infection led to an increase of the contents of hydroxycinnamic acids (caftaric acid, sinapic acid glucose derivate and coutaric acid), flavanols (procyanidin B1, procyanidin dimer 3, catechin, epicatechin) and flavonols (quercetin 3-O-glucuronide, quercetin 3-O-glucoside) especially in the period up to vérasion. The study demonstrated that at certain phenological key-stages infection with phytoplasma (BN) induced different alterations in enzyme activities and in the contents of biochemical compounds from primary and secondary metabolism. 相似文献
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Orobanche amethystea Thuill.,O. loricata Reichenb. andO. pubescens D’Urv. were found to parasitize the roots of cultivated plants in Israel.Orobanche pubescens is known from the local flora, and was now found to cause damage in parsley fields and toTropaeolum majus L. (nasturtium) in ornamental gardens.Orobanche amethystea andO. loricata are known as occasional weeds in Europe and were recently found for the first time in Israel.Orobanche amethystea densely populated vetch fields in Israel, andO. loricata was found in ornamental gardens. A key for the identification ofOrobanche species in cultivated areas in Israel is given, based on morphological features.
http://www.phytoparasitica.org posting Jan. 13, 2002. 相似文献
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Knowledge of the occurrence of sound and dead knots on the surface of sugi is important for the classification and application of the material. This study examined a color vision system for detecting sound and dead knots on sugi. The system can be conceptually divided into three components: a CCD-camera scanning system, an image-segmenting module, and a rule-based defect identifying module. The results showed that the potential defect regions could be located by Otsus threshold algorithm in conjunction with t-test analysis. The accuracies of locating sound knots and dead knots were 92.6% and 97.1%, respectively. The rule-based approach was used to identify sound and dead knots and the identifying accuracies for sound knots and dead knots were 92.0% and 94.1%, respectively. The overall detection accuracy of the system was 87.6%. The results indicated that the rule-based color vision system is an efficient means of detecting sound knots and dead knots on sugi. 相似文献
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Low temperature is one of the major limiting environmental factors which constitutes the growth, development,productivity and distribution of plants. Over the past several years, the proteins and genes associated with freezing resistance of plants have been widely studied. The recent progress of domestic and foreign research on plant antifreeze proteins and the identification and characterization of plant antifreeze protein genes, especially on expression regulatory mechanism of plant antifreeze proteins are reviewed in this paper. Finally, some unsolved problems and the trend of research in physiological functions and gene expression regulatory mechanism of plant antifreeze proteins are discussed. 相似文献