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１材料与方法１．１预报要素的确立根据安徽省望江县棉花病虫测报站资料，棉红铃虫第三代卵量与青铃被害程度极显著相关（ｒ＝０．７３９８，Ｐ０．０１＝０．７０８）。因此以棉红铃虫第三代卵量为预报对象ｙ，就能正确反映当代棉花的受害程度。从１９７４～１９８５年历... 相似文献
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长江下游棉花落叶型黄萎病发生消长与气象因子关系分析 总被引：2，自引：0，他引：2
１９９３～１９９７ 年, 在江苏省常熟市徐市镇棉花落叶型黄萎病地（致病小种为落叶型ＪＣ５）,对苏棉８ 号从６ 月初至９ 月中旬进行棉花黄萎病调查, 并结合当地的气温、雨日等气象因子对黄萎病的发生消长关系进行统计分析。结果表明, 平均气温２３℃最适宜发病, 平均气温大于２８℃时发病停止（隐症）。黄萎病的日增病指与平均气温、雨日相关性较强, 与雨量相关性较差。合并５ 年的资料, 通过多因子筛选, 得出日增病指（Ｙ）与雨日（Ｘ２）、大于２３℃的有效积温值（Ｘ１）的关系式： Ｙ＝ － ０．１４９４９Ｘ１＋ ０．１４５４４Ｘ２＋ ０．９３５５１。 相似文献
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“硒芽菜”硒积累规律的研究 总被引：6，自引：0，他引：6
研究表明，培育“硒芽菜”所选用的Ｎａ２ＳｅＯ３的最佳深度为１×１０＾－６－２０×１０＾－６，在此范围内芽菜所积累的硒量与浓度有明显的线性关系。回归方程：绿豆芽Ｙ＝－０．０１１９３＋０．９２７２Ｘ，ｒ＝０．９８８６；苜蓿芽Ｙ＝２．５０９５＋３、６６３７Ｘ，ｒ＝０．９８３１。苜蓿芽硒的积累量大约为绿豆芽的５倍。“硒芽菜”的感官品质和对照相比无差异，具具有栽培普遍、周年供应等优点，可作为一种良好的硒补充 相似文献
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青海省家驴染色体核型研究 总被引：2，自引：0，他引：2
采用外周血淋巴细胞培养方法和常规染色体制备分析技术，对青海省家驴染色体核型进行了研究分析。结果表明：家驴染色体数目为２ｎ＝６２，常染色体形态类型为１６ｓＴ＋１４ｓＭ＋１４Ｍ＋１６Ｔ，性染色体类型Ｘ为ｓＭ，Ｙ为Ｔ，公母驴染色体核型式为６２，ＸＹ和６２，ＸＸ；染色体总臂数为ＮＦ＝１０７（♂），１０８（♀）。 相似文献
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不同年代棉花品种产量构成、纤维品质及其系谱分析 总被引：20，自引：4，他引：20
对５０年来我国自育的有代表性的棉花品种２０份进行了比较研究，结果表明，棉花单产呈递增趋势，９０年代棉花品种比５０年代品种皮棉增产１７．７３％，平均每年增产皮棉３．３８４ｋｇ·ｈｍ－２，产量增加主要是衣分和单株结铃数增加所致，衣分呈递增趋势，年均递增０．１００２个百分点；单株结铃数增加１．６个。新品种的子指变小，衣指变大；棉花衣分与皮棉产量呈显著正相关（ｒ＝０．７００３＊＊），衣分对棉花产量贡献最大（ Ｐ３ｙ＝０．５８１０），单株铃数次之（Ｐ１ｙ＝０．２８５８），铃重最低（Ｐ２ｙ＝０．１３２６）。棉花纤维品质逐步得到改良，绒长变长，纤维强度变大；棉花遗传基础狭窄。 相似文献
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棉花栽培计算机模拟决策系统(COTSYS) 总被引：22，自引：1，他引：22
棉花栽培计算机模拟决策系统（简称：棉花系统）（英文名： ＣＯＴｔｏｎ ｃｕｌｔｉｖａｔｉｏｎａｌｓｉｍ ｕｌａｔｉｏｎ ａｎｄ ｄｅｃｉｓｉｏｎ－ ｍ ａｋｉｎｇ ＳＹＳｔｅｍ ， 简称ＣＯＴＳＹＳ），是在大量田间试验和生产示范信息反馈基础上，结合劳模、专家经验和模式化栽培技术，历时７年研制完成的。系统由数据库管理、模拟与分析、栽培决策、病虫害防治及经济效益分析５个子系统组成，可用于棉区棉花生产和当年栽培优化决策，制作栽培决策方案和栽培规程；进行棉区生产潜力分析，模拟预测棉花生长发育和产量的形成；进行有关参数和数据库管理，以及病虫害防治决策和经济效益分析等。系统适在特早熟、中早熟及中熟三个生态棉区应用效果良好。 相似文献
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离子注入诱发棉花过氧化物酶同功酶及农艺性状变异的研究 总被引：2，自引：0，他引：2
本文分析了氮离子注入处理棉花种子诱发Ｍ１植株第二真叶过氧化物酶同功酶（ＩＰＯ）变异的遗传表现；Ｍ＝ＩＰＯ和农艺性状变异的频率及类型，探讨了剂量效应及ＩＰＯ变异与农艺性状变异的关系。结果表明：Ｍ１ＩＰＯ变异有些是非遗传的，Ｍ２中ＩＰＯ不同酶带对氨离子注入的敏感性及最佳诱变剂量不同；氮离子注入能诱发较高频率的ＩＰＯ变异及数量性状和多个性状的同时变异，可在较轻的Ｍ１损伤下获得较高的Ｍ２农艺性状变异频率，Ｍ２ＩＰＯ和农艺性状变异频率与Ｍ１ＩＰＯ变异频率的关系可用Ｙ＝Ａ＋ＢＸ＋ＣＸ２来描述。在Ｍ２铃数和早熟性变异株中均可观察到第二真叶ＩＰＯ第８条酶带，而铃重和株高变异株中可观察到第６条酶带。 相似文献
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水稻生长发育的进程可以用某一品种或组合不同生育时期的叶龄来表达。本研究利用叶龄余数来鉴定稻穗分化的进程，大量植株解剖实验发现，幼穗开始分化的叶龄余数为４．０左右，这与前人研究为３．０或３．５有所不同，并建立起稻穗分化各期（Ｙ）与叶龄余数（Ｘ）之间的直线回归方程Ｙ＝Ａ＋ＢＸ，其Ｆ测验为极显著。此外还通过调查出叶速度，记载有效积温，经统计分析发现，有效积温与叶龄增长关系相当密切，以此建立了叶龄（Ｙ）与有效积温（Ｘ）之间的回归关系Ｙ＝Ｃ＋ＤｌｇＸ，其相关系数（ｒ）这极显著，从而实现了由有效积温预测叶龄的目的。此二项研究结果为利用叶龄来指导栽培技术措施提供了一套模式化的理论依据和方法，在生产上有一定的参考价值。 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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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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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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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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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
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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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Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed. 相似文献
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[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho... 相似文献
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E. Keep 《Euphytica》1986,35(3):843-855
Summary Cytoplasmic male sterility (cms) is described in the F1 hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf
1) and recessive for the other (Rf
2).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph
3(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf
1(one of two dominant additive genes controlling early season leafing out) indicated that Rf
1and Rf
2were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf
1, and 0.15 for Lf
1-Sph
3were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph
3.It is suggested that competitive disadvantage of lf
1-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph
3. Poor performance of lf
1- (and possibly lf
2-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off). 相似文献
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Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques. 相似文献