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播前氟乐灵土壤处理减轻棉花枯萎病的效果 总被引：2，自引：0，他引：2
田间试验结果，除草剂氟乐灵４８％乳油以０．８６４ｋｇ／ｈｍ２作棉苗播前土壤处理，可明显减轻棉花枯萎病的发生，在现蕾期，施用氟乐灵后对感病品种沪棉２０１１和抗病品种中棉１２枯萎病株发病率的防治效果分别为４８．２５％～６９．４２％和４９．４１％～７０．５９％；病害严重度也明显下降，对沪棉２０１１和中棉１２的抑制作用分别为５５．９８％～６４．７８％和４６．３６％～７０．４５％。从棉花收获后进行的剖秆检查看，氟乐灵施用后不仅降低了枯萎病菌对棉花的侵染率，对沪棉２０１１和中棉１２的防治作用分别为１６．０２％和２６．８２％；而且也减轻了受侵棉花植株木质部的病变程度，对沪棉２０１１和中棉１２植株木质部病变的抑制作用分别为２２．０２％和３６．３３％，对施药２个月后土壤中枯萎病菌接种体密度的测定结果表明，氟乐灵并不影响土壤中枯萎病菌的接种体密度。综上所述结果，氟乐灵播前土壤处理可以减轻田间棉花枯萎病的发生，其原因是氟乐灵处理诱发了棉株对枯萎病的抗侵入和抗扩展能力。 相似文献
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用比色法测定了甲哌啶在棉子和土壤中的残留及其在棉叶和土壤中的消解动态。棉子、棉叶和土壤的方法添加回收率７１．５％～７４．８％、７２．８％～８１．７％和８３．３％～９２．２％，变异系数４．９８％～９．８４％、４．７９％～７．１５％和５．１６％～７．１３％，最小检出浓度０．２８、０．１９和０．２９ｍｇ·ｋｇ－１。测定结果表明，按照甲哌啶推荐用量处理棉花，棉子中未检出甲哌啶。甲哌啶在棉叶和土壤中的半衰期为９．４１～９．４４天和８．２天。 相似文献
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内生假单胞菌诱导棉花抗蚜性的研究 总被引：2，自引：1，他引：1
研究采用胚轴切断扦插法诱导棉株产生抗虫性。该方法是在棉花２片真叶期,将其根茎在下胚轴处切断,接种假单胞菌,扦插使其生根。通过该机械损伤及菌处理,诱导棉株产生系统抗性。实验设菌诱导扦插株和无菌诱导扦插株两项处理,以自然生长棉株作对照。诱导棉株扦插时,接种假单胞菌（ＰｓｅｕｄｏｍｏｎａｇｌａｄｉｏｌｉＤ－２２５１）的抗利福平突变菌株。生根后取其根、茎、叶组织,检测其体内接种菌菌量,结果发现诱导菌能够在棉株体内定殖,其浓度高低顺序为：根＞茎＞叶;诱导后,棉株体内单宁含量在各生长期均有不同程度提高,菌诱导株和无菌诱导株的变幅分别为３０．７８％～２８９．９９％和３．８８％～１３９．６９％。除盛花期外,各生长期酚含量也有所提高,菌诱导株和无菌诱导株的变幅分别为２．６０％～３６．２２％和１．３２％～２６．１６％;温室条件下,对诱导株上的自然感蚜状况进行了调查;５叶期,菌诱导和无菌诱导棉株的百株蚜量分别降低７４．９５％和４３．５１％,有蚜株率分别降低６７．８４％和５４．９８％;７叶期,百株蚜量分别降低３５．９８％和１７．２１％,有蚜株率分别降低３２．２４％和１７．２１％。 相似文献
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麦棉套种不同间距对棉花生态环境及生育的影响 总被引：1，自引：0，他引：1
于１９９２－１９９４年研究了套种春棉５－２式配置方式麦棉不同间距的生态环境，及其对棉花生长和产量的影响。结果表明，麦棉间距越大，虽然光、热、水环境因子综合作用有利于棉苗生长，但因棉花的小行距太小，不利于棉株中、后期生长发育和获得高产量。３年结果表明·采用５－２式配置方式公顷产皮棉１５００ｋｇ和１５００ｋｇ以上，伏前桃和伏桃应占“三桃”总数的４５％以上和５２％以上，麦棉间距以２６．７－３３．３ｃｍ为好．研究结果可作为黄淮海地区推广麦套春棉的参考。 相似文献
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棉花苗期病害拮抗细菌的筛选及其防效测定 总被引：4，自引：0，他引：4
从山东德州棉田采集病株根际土样12份,以棉花立枯丝核菌(Rhizoctonia solani)为指示菌,采用对峙法对平板稀释法分离的菌株进行抑菌初筛,共筛选出具有拮抗作用的细菌菌株11支.其中D24菌株对上述指示菌皆有很强的拮抗效果,该菌的发酵液对棉花立枯丝核菌、棉花黑斑病菌(Alternaria macrospora)、棉花红腐病菌(Fusarium moniliforme)、棉花枯萎病菌(Fusarium oxysporum)4种常见的棉花苗期病菌也有很好的抑制作用.室内小区试验表明,棉苗用D24菌株发酵液处理后,防效可达50.1%. 相似文献
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北疆高产棉花养分吸收特性的研究 总被引：38，自引：7，他引：38
本文以新陆早４号为材料，研究了北疆高产棉花群体（１８００ｋｇ·ｈｍ－２）条件下棉株Ｎ、Ｐ２Ｏ５、Ｋ２Ｏ养分的吸收特性。结果表明，棉花茎枝、叶片、花蕾、铃壳、子棉中的Ｎ、Ｐ２Ｏ５的含量随生育进程呈下降趋势；Ｋ２Ｏ含量在铃壳中呈上升趋势，在其它器官中呈下降趋势。棉株对Ｎ、Ｐ２Ｏ５、Ｋ２Ｏ的吸收均呈Ｌｏｇｉｓｔｉｃ曲线变化，养分吸收的快增期出现在出苗后５８～９７ｄ，此期吸收了约养分总量的６０％，是需肥最大的时期。棉株对养分的吸收分配中心与干物质积累分配中心一致。在本试验中，公顷产１８００～１９００ｋｇ皮棉从土壤中吸收Ｎ为２４５．０～２７０．１ｋｇ，Ｐ２Ｏ５为７２．４～７５．５ｋｇ，Ｋ２Ｏ为２６９．５～２７１．９ｋｇ。 相似文献
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Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
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C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
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Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
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G. H. Kroon 《Euphytica》1994,76(1-2):125-125
Summary
K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes. 相似文献
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Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
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Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed. 相似文献
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Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes. 相似文献
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W. Erskine M. Tufail A. Russell M. C. Tyagi M. M. Rahman M. C. Saxena 《Euphytica》1993,73(1-2):127-135
Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed. 相似文献
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D. A. Bond G. J. Jellis G. G. Rowland J. Le Guen L. D. Robertson S. A. Khalil L. Li-Juan 《Euphytica》1993,73(1-2):151-166
Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses. 相似文献
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Chunli TANG Fengxian ZHAO Hongxia CHEN Jiabao MA Jiangcun WEI Meiyan QIU Zhen XIE 《Medicinal Plant》2019,(6):60-65
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination... 相似文献