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1.
为了比较5个茶用菊新品种(系)的产量水平,并筛选出获得高产的定植期和摘心方案,以 ‘苏菊10号’、‘苏菊12号’、‘苏菊13号’、‘CH1-44’、‘CH5-13’ 为试材,采用三因素裂区试验设计,主区为早、中、晚3个定植期,裂区为5个新品种(系),裂裂区为4种摘心方案,比较不同栽培措施下植株生长和产量的差异.结果表明: 5个新品种(系)中,‘CH5-13’和‘苏菊13号’产量相对较高,‘CH1-44’和‘苏菊10号’产量次之,‘苏菊12号’产量最低;5月27日中期定植、二次摘心措施下5个新品种(系)的株高、冠幅、单株花数、花径、单花鲜质量、单株产量和单位面积产量均显著优于其他处理,较5月7日和6月13日定植分别提高16.0%和19.0%、18.0%和22.8%、36.7%和42.2%、11.1%和2.3%、13.0%和4.0%、47.8%和36.6%、48.5%和36.7%.随着摘心时间的推迟,株高显著降低,二次摘心株高较不摘心降低50.2%;二次摘心处理的冠幅、单株花数、单花鲜质量、单株产量和单位面积产量最高,较不摘心依次提高17.0%、29.1%、5.5%、34.0%和34.8%.品种(系)、定植期、摘心方案3个因素对茶用菊生长性状和产量影响作用的大小依次为:定植期>品种>摘心.  相似文献   
2.
TAKEUCHI (1969) provides a uniformly most powerful (UMP) one side test for testing the location parameter of the two parameters exponential model when the scale parameter is unknown. The power of his similar size α test depends, however, on the unknown scale parameter. In this case and in more general situations when there exists a sufficient statistic for the nuisance parameter, the theory of generalized THOMPSON's distributions, more specifically, the Thompsonization of a test statistic, LAURENT (1959, 1972) provides a UMP test whose power does not depend on the nuisance parameter. Examples of application of the general nuisance parameter free test procedure include here the truncated exponential, the inverse Gaussian, and the geometric distributions.  相似文献   
3.
不同菜豆品种(系)对美洲斑潜蝇种群参数的影响   总被引:9,自引:1,他引:8  
李绍勤  邓望喜  谢宪高 《生态学报》2002,22(8):1354-1357
在温度 (2 7± 1 )℃、湿度为 70 %± 5 %的实验室条件下 ,测定了菜豆属矮生菜豆 (无架 )、西宁豆、83 -B架豆、白花架豆、新春架豆等 5个菜豆品种 (系 )对美洲斑潜蝇种群参数的影响。结果表明 ,美洲斑潜蝇的各虫态发育历期 ,成虫寿命 ,卵、幼虫和蛹的存活率 ,蛹重 ,成虫产卵量和持续产卵期在 5个品种 (系 )间均存在显著性差异 (α=0 .0 5 )。其中美洲斑潜蝇在选择性弱的品种 83 -B架豆上表现为幼虫、蛹的历期最长 ,蛹的存活率最低 ;在选择性强的白花架豆上则表现为卵 -蛹的历期最短 ,幼虫存活率最高 ,蛹重最重  相似文献   
4.
Summary Genetic effects for varietal value are defined at the level of the population of k-parent synthetic varieties. A simple expression for the total variance among synthetics arises directly from these definitions. A general expression for the covariance among related synthetics is given. Genetic effects are also defined in a completely general way so as to allow for any system of testing and used to derive an expression for the genetic advance in recurrent selection for varietal value. Covariances between relatives evaluated in the system of testing and in varietal combination are introduced, allowing a direct expression of the genetic advance in varietal development when parents are selected either individually or in groups. Some general implications for plant breeding are outlined.Dedicated to Professor F.W. Schnell on the occasion of his 65th birthday  相似文献   
5.
Summary A general model for the evolution of pathogen populations on mixtures or multilines is developed. This model is used to extend previous analyses of the effects of the widespread cultivation of multilines on the evolution of virulence in obligate parasites to mixtures of lines carrying different numbers of resistance genes. It is concluded that the composition of an equilibrium pathogen population growing on a multiline may vary within wide limits and the prinicipal determinant of its composition is the number of components in the multiline and the resistance genes they carry. Other factors of importance are (i) the relative contribution made by each host class (with different numbers of resistance genes) to the pathogen spore pool each generation; (ii) the levels of stabilizing selection against unnecessary virulence genes; and (iii) the way in which unnecessary genes for virulence combine to reduce pathogen fitness. Conditions for the fixation of avirulent biotypes in the pathogen population and the evolution of a pathogen superrace are given for multilines of various compositions.Paper No. 9246 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina. This investigation was supported in part by NIH Research Grant No. GM 11546 from the National Institute of General Medical Sciences  相似文献   
6.
Summary Our field surveys conducted in 10 Hungarian grape producing areas have revealed that the nutrient contents of vine leaves of different grape varieties were closely correlated with the EUF-nutrient contents of different soil types with different contents of clay. Resulting from these relationships the following EUF-nutrient values are considered as required for optimal nutrition of the vine-stock to attain grape yields of 10–12 t/ha in the areas under investigation:  相似文献   
7.
Genetic distances (GDs) based on molecular markers are important parameters for identifying essentially derived varieties (EDVs). In this context information about the variability of molecular markers within maize inbred lines is essential. Our objectives were to (1) determine the variation in the size of simple sequence repeat (SSR) fragments among different accessions of maize inbreds and doubled haploid (DH) lines, (2) attribute the observed variation to genetic and marker system-specific sources, and (3) investigate the effect of SSR fragment size differences within maize lines on the GD between maize lines and their consequences for the identification of essentially derived varieties. Two to five accessions from nine inbred lines and five DH lines were taken from different sources or drawn as independent samples from the same seed lot. Each accession was genotyped with 100 SSR markers that evenly covered the whole maize genome. In total, 437 SSR fragments were identified, with a mean of 4.4 alleles per locus. The average polymorphic information content (PIC) was 0.58. GD estimates between two accessions of the same genotype ranged from 0.00 to 0.12 with an average of 0.029 for inbred lines and 0.001 for DH lines. An average of 11.1 SSRs was polymorphic between accessions of the same inbred line due to non-amplification (8.1 SSRs), heterogeneity (4.0 SSRs) or unknown alleles (2.6 SSRs). In contrast to lab errors, heterogeneity contributed considerably to the observed variation for GD. In order to decrease the probability to be suited for infringing an EDV threshold by chance, we recommend to increase the level of homogeneity of inbred lines before applying for plant variety protection.  相似文献   
8.
辽河流域栽培稻对二化螟(Chilo suppressalis)的抗性   总被引:2,自引:0,他引:2  
郝丽霞  韩永强  侯茂林  廖晓兰 《生态学报》2008,28(12):5987-5993
采用活体成株鉴定法测定了辽河流域主栽水稻品种对二化螟发育和为害的影响,同时测定了不同品种的主要形态特性、硅细胞数量和主要生化特性,评价这些品种对二化螟的抗性、分析其发生的可能机制。盐丰47对二化螟幼虫表现出较好的抗性,在沈农265上二化螟幼虫体重最小。在所测定的特性中,螟害株率与不同品种倒二叶叶角的自然对数之间具有显著的正相关关系,与稻茎Si含量之间具有显著的负线性相关关系;二化螟幼虫体重只与不同品种稻茎直径之间具有显著的正线性相关关系.研究结果对水稻品种杭件利用和未来水稻抗件育种的意义。  相似文献   
9.
【目的】研究烟粉虱Bemisia tabaci(Gennadius)对同种寄主不同品种的选择性及适生性,可为该寄主抗性品种的选育和烟粉虱的综合治理提供理论依据。【方法】在温度(29±2)℃、湿度80%±5%的自然光照温室内,进行B型烟粉虱对不同茄子品种的选择性以及这些品种对其生长发育、繁殖、存活和生命表参数的影响实验。【结果】B型烟粉虱对茄子不同品种的选择及适生性具有一定的差异,在14个茄子品种或材料中,B型烟粉虱对黑马紫长茄的选择性最强,对龙茄1号的选择性最弱;B型烟粉虱从卵发育到成虫的存活率在辽茄3号上最低,在龙茄1号上最高;世代发育历期在辽茄3号上最短,在徐州长茄上最长。此外,B型烟粉虱在苏崎茄、扬茄1号和紫圆茄上的种群趋势指数(I)分别为68.7215、37.4675、25.6245,表明B型烟粉虱对这3个品种的适生性为苏崎茄>扬茄1号>紫圆茄。  相似文献   
10.
Ten Napier grass [Pennisetum purpureum Schumach (Poaceae)] varieties, used in various parts of Kenya as animal fodder, were tested for their potential role as a trap crop in the management of the gramineous spotted stemborer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), through habitat manipulation. Oviposition preference and larval survival and development were determined for each of these varieties under laboratory and screen‐house conditions. Two‐choice tests revealed that seven of the varieties tested were preferentially chosen by gravid female moths for oviposition over a susceptible maize cv. Inbred A. Larval survival was significantly lower on the majority of the Napier grass varieties (about 10%) than on maize cv. Inbred A (about 60%). Similarly, larval development was about 2 weeks longer on the majority of the Napier grass varieties. It was concluded that four of the varieties tested (Bana, Ex‐Machakos, Gold Coast, and Ex‐Nyanza‐2) had potential for use as trap crops in C. partellus management because they were more preferred by the borer moths for oviposition and allowed minimal survival of the larvae. This minimal larval survival is desirable in the conservation of C. partellus natural enemies when the cultivated host plant is out of season.  相似文献   
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