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橡胶主要无性系对白粉病抗性的鉴定 总被引：4，自引：2，他引：2
1983—1990年在抗病系比苗圃和大田鉴定了48个主要橡胶品系对白粉病的抗性。结果表明:RRIC52、红山67—15等品系具有高度抗病力;热研11—9、RRIC102、IAN873;湛试8—67—3等品系,具有中度抗病力,热研14—20、八—36—3、保亭938、热研7—33—97、文昌12—12、RRIC100、RRIM600等品系,也具有中度抗病力,但个别年份易发病,属于中抗至中度感病品系;其他品系都不同程变地感病,其中PB5/51、热研88—13、PR107、热研44—9等品系尤其感病。 相似文献
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橡胶炭疽病是橡胶树重要的叶部病害之一,已成为影响天然橡胶产量的主要限制因素。我国对橡胶树炭疽病病原物鉴定结果一直为胶孢炭疽(Colletotrichum gloeosporioides）,直到2008年在云南首次发现危害我国橡胶树的炭疽菌有尖孢炭疽(Colletotrichum acutatum）。针对我国对于尖孢炭疽病研究甚少的现状,研究组对从广东、云南、海南分离得到的橡胶树尖孢炭疽病菌菌株进行了致病性测定,并用菌丝体接种鉴定方法对国内橡胶树主要种质和品系进行抗尖孢炭疽病评价。结果发现,在供试的91个种质中,有抗病种质6个(占总数的6.6 %)、轻感病种质57个(占总数的62.6 %)、易感病种质28个(占总数的29.8 %);在18个国内主推品种的抗病性评价中发现抗病品种4个(占总数的22 %)、轻感病品种11个(占总数的63 %)、易感病品种1个(占总数的5.6 %)。SAS统计分析结果表明,不同种质或品种对尖孢炭疽病的抗性水平存在明显差异;在α=0.05水平上,抗病种质或品种与轻感病种质或品种及易感病种质或品种间的差异达到显著水平。 相似文献
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从1982—1985年共鉴定品种(系)1253份,总结了适合大量材料田间人工接种鉴定和评价方法。结果表明,抗细菌斑点病的抗源材料丰富,高抗材料322份,抗病材料247份,其余为中等以上感病材料。对于田间的人工接种鉴定结果的可靠性易受年度间气候差异的影响,提出设立感病标杆品种和苗期1—2片复叶展开时进行室内人工接种鉴定。植株发病与子叶发病不呈正相关,所以在选择抗源做杂交亲本时,应选择植株与子叶均抗病的材料。 相似文献
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橡胶树炭疽菌生物学和侵染特征研究 总被引：8，自引：0，他引：8
橡胶树炭疽病是危害我国橡胶树的一种重要叶部病害,致病菌为胶抱炭疽菌。对其生物学特性研究结果表明,在28 ℃下,有利于菌丝体生长、产孢和孢子萌发 。最适合菌丝体生长的pH值为6。黑暗下有利于孢子萌发和菌丝体生长,但产孢则不如在光照条件下。在100 %相对湿度下孢子萌发率最高。在葡萄糖、橡胶叶汁和琼脂胶等营养液中, 孢子萌发率高于清水对照。对其侵染特征研究结果表明,主要侵染源为受害嫩梢和半枯死枝条,寄主范围广泛。病菌可从伤口、气孔和表皮3种途径入侵,风雨是传播媒介。潜育期一般3~6d,条件最适宜时潜育期为1~ 2d。田间气温21~24℃、相对湿度大于95%时,病菌产孢多,侵人迅速,病斑扩展快 相似文献
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辽宁省常用玉米自交系及杂交种对弯孢菌叶斑病的抗性鉴定 总被引：1，自引：0，他引：1
通过人工接种的方法对辽宁省常用的３０个玉米自交系及２６个杂交种进行了玉米弯孢菌叶斑病的抗性鉴定。结果表明：所鉴定的自交系及杂交种中,绝大部分感病,仅有个别的表现抗病。 相似文献
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水稻品种对稻瘟病抗性组分的研究 总被引：6，自引：2，他引：6
应用主成分分析法研究了21个水稻品种对稻瘟病9个抗性组分。结果表明，第一主成分为抗稻瘟病病害基本因子，它主要由产孢量、成株叶瘟严重度、成株病斑孢子层级指数、苗期叶瘟严重度和苗期病斑孢子层级指数5个有效组分构成；第二主成分为抗穗瘟因子，主要由穗颈瘟严重率构成。两主成分的特征根之和占全部特征根的96.2%。该两综合因子几乎能反映原来抗性组分的全部信息量。此外，研究还表明，选用苗期病斑孢子层级指数、产孢量、成株期或苗期叶瘟严重度和穗颈瘟严重率作持久抗性的病区病圃抗性组分鉴定的定量指标是可行的。 相似文献
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Lakshman Lal 《Potato Research》1987,30(2):329-334
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong
(1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage,
sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over
45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield
of a subsequent crop. 相似文献
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《Journal of Crop Improvement》2013,27(2):81-114
Summary The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices. 相似文献
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M. I. Siri P. Villanueva M. J. Pianzzola L. Franco Fraguas G. Galván M. Acosta F. Ferreira 《Potato Research》2004,47(3-4):127-138
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results
for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin
presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear
relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins
and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds. 相似文献
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Novel food and non-food uses for sorghum and millets 总被引：4，自引：3，他引：4
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity. 相似文献
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Alejandro Carlos Tozzini María Fernanda Ceriani María Verónica Saladrigas H. Esteban Hopp 《Potato Research》1991,34(3):317-324
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets
that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and
slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging
toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta.
Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact). 相似文献
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Alejandro M. S. Mayer Abimael D. Rodríguez Orazio Taglialatela-Scafati Nobuhiro Fusetani 《Marine drugs》2013,11(7):2510-2573
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories. 相似文献
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Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase). 相似文献
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Rita Favas Janaína Morone Rosrio Martins Vitor Vasconcelos Graciliana Lopes 《Marine drugs》2022,20(3)
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms. 相似文献