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1.
敦煌阳关保护区湿地植物群落优势种种间关系分析 总被引：2，自引：1，他引：1
用χ2检验和Pearson 相关系数检验以及Spearman 秩相关系数检验方法,分析了甘肃敦煌阳关保护区湿地植物群落中16 个优势种的种间关联性,从而可为其湿地的保护、管理和恢复提供科学依据。结果表明：多物种总体关联性检验结果显示16 个优势种总体种间呈负关联,表明该群落结构不稳定;χ2检验中呈正相关的物种对有53 个,呈负相关的物种对有67 个,正负关联比为0.79;Spearman 秩相关系数检验与χ2检验和Pearson 相关系数检验相比,有较高的灵敏度,其中52 个种对呈正相关,68 个种对呈负相关,正负关联比为0.76;3 种检验结果都表明,大多数种间关联程度不显著,且负关联的种对数多于正关联,说明敦煌阳关保护区湿地植物群落比较脆弱,群落的结构简单,仍处于演替之中。根据Spearman 秩相关系数结果,将16 个优势种划分为3 种类型的生态种组。种间关联性分析对全面认识阳关保护区湿地优势种间的相互关系具有重要意义,可为该保护区湿地资源的可持续利用和多样性保护提供理论依据。 相似文献
2.
山西左云县兴隆沟煤矿矸石山自然定居植物群落优势种种间关系研究 总被引：1，自引：1，他引：0
为了探明矸石山自然定居植物群落的物种组成和种间关系,采用χ2检验、Pearson相关系数、Spearman秩相关系数检验数量分析方法,对山西省左云县兴隆沟煤矿矸石山自然定居植物群落12个优势种组成的66个种对间的关联性进行了研究。结果表明：（1）χ2检验有30个种对呈正相关,36个种对呈负相关,正负关联比为0.83;Pearson相关系数检验有19个种对呈正相关,47个种对呈负相关,正负关联比为0.40;Spearman秩相关系数检验有29个种对呈正相关,37个种对呈负相关,正负关联比为0.78;与χ2检验和Pearson相关系数相比,Spearman秩相关系数检验具有较高的灵敏度。66个种对中负相关居多,达到极显著或显著的种对少,说明兴隆沟煤矿矸石山自然定居植被群落比较脆弱,群落结构简单,仍处于演替初、中期阶段;（2）优势种披碱草、沙生冰草和旱榆等种对间呈极显著正相关或正相关,它们为地带性分布植物种类,耐旱、耐寒、耐贫瘠,生态适应性强,可用于该区煤矸石山人工植被恢复的优选先锋物种进行混合种植;而优势种小叶杨与披碱草、沙生冰草等种对间呈负相关,在人工植被恢复中不宜混种;（3）根据Spearman秩相关系数结果,采用聚类分析方法,可将12个优势种群划分为3种生态种组。 相似文献
3.
承德县人工油松林林下草本植物种间关系研究 总被引：2，自引：0，他引：2
以承德县人工油松林林下草本植物为研究对象,采用χ2检验、Pearson相关分析和Spearman秩相关分析检验了35个物种595个种对间的关联性,研究结果表明：(1) 在表征种间关联方面,Spearman秩相关分析较χ2检验、Pearson相关分析灵敏度高;(2)3种检验方法的一致结果为:负相关的种对数远多于正相关,而极显著和显著相关的种对数所占比例较低,大多数种间关系松散,独立性相对较强,群落还处于演替之中;(3)种对间的正相关是由于它们的生态适应性相近,是生态位重叠的表现;而种对间的负相关正是生态位分离的结果。 相似文献
4.
阳泉矿区煤矸石山复垦地不同植被下草本植物群落优势种种间关系及生态位 总被引：3，自引：1，他引：2
《中国农学通报》2019,(1)
为揭示煤矸石山不同人工植被下草本植物群落优势种种间关系和生态位特征。在植物样方调查的基础上,采用χ2检验、Pearson相关系数、Spearman秩相关系数以及生态位宽度和重叠分析方法,分析了山西阳煤五矿2003年复垦的煤矸石山不同植被下草本植物群落12个优势种种间关系。结果表明:(1)不同植被下草本植物群落12个优势种的正负关联比小于1,整体间呈现负相关,呈极显著和显著相关的种对较少,种间关系较松散、关联性差;(2)12个优势种划分成3个生态种组,导致其生态种组分化的主导因子为水分条件;(3)优势种种间关联程度与生态位重叠值具有一致性,但生态位宽度与重叠值无明显线性相关;(4)自然定居的草本植物白羊草、茵陈蒿和阿尔泰紫菀对煤矸石山恶劣生境的生态适应能力和生存竞争力较强。该复垦地不同植被下草本植物群落稳定性差,仍处于演替的初、中期阶段;自然定居的草本植物白羊草可作为未来煤矸石山生态恢复的优选先锋植物种,但人工种植的高羊茅与其呈负相关,故二者不宜混种。 相似文献
5.
民勤荒漠区霸王群落种间联结性分析 总被引：2，自引：2，他引：0
为了从种间联结性的角度揭示霸王群落的稳定性机制,基于2×2列联表,运用多物种总体联结性,各物种间联结性、联结系数、共同出现百分率,对民勤荒漠区霸王群落2大分布区的种间联结性进行分析。结果表明：五托井霸王群落总体表现为联结程度不显著的正关联,群落处于比较稳定的阶段,建群种霸王的优势明显,整个群落将朝着稳定无关联的方向发展;石榴井西霸王群落总体表现为联结程度不显著的负关联,群落处于比较不稳定的演替阶段。五托井霸王群落内12个主要植物种构成的66个种对间,有显著相关性的仅占12%,正联结程度明显高于负联结程度,但很多χ2检验相关性不显著的种对间,尤其是霸王与其他种对间的联结程度极高,群落处于稳定阶段;石榴井西霸王群落内12个主要植物种构成的66个种对间,有显著相关性的仅占7.58%,负联结程度明显高于正联结程度,霸王与其他物种间的联结系数AC均表现为相互独立,群落处于比较不稳定阶段。群落稳定性、群落总体联结性及群落内物种间联结性相互之间呈正相关关系。 相似文献
6.
莽山南方铁杉群落种间关系研究 总被引：2，自引：1，他引：1
为了研究莽山南方铁杉群落种间关系,以便更好地保护这种植物,笔者采用方差比率法（VR）,应用Jaccard指数、Dice指数和Pearson相关系数、Spearson秩相关系数,对莽山自然保护区南方铁杉群落种间关系进行分析。结果表明：（1）南方铁杉群落中主要种群总体上表现出正关联;（2）群落中种间联结的显著度较低,其中有显著正相关2对,显著负相关4对,极显著正负相关各1对,南方铁杉与水青树呈显著负联结,与香樟呈极显著负联结;（3）大多数种对间关联程度较低,存在极大排斥性的种对较少,表明目前南方铁杉群落处于较成熟阶段。研究种间关系时,结合多种方法共同分析,能够更有效地寻找种间潜在的联结关系,最后对南方铁杉的保护提出了一些建议。 相似文献
7.
采用2×2列联表,对衡阳盆地自然恢复灌丛阶段植物群落中20个主要种的种间联结性进行分析,结果表明：（1）自然恢复灌丛阶段群落优势种多物种间显著负关联;（2）群落中重要值较高的20个种群组成的190种对中,有58对呈显著正联结,有34对呈显著负联结;（3）以X2为基础,结合联结系数和种间关联度的3个指标较好地测定了20个主要植物种群的联结性。 相似文献
8.
华北驼绒藜种群空间分布格局及其环境依赖性研究 总被引：1，自引：0，他引：1
应用地统计学中的半方差分析方法对4种群落类型华北驼绒藜种群的空间分布格局进行研究.结果表明:华北驼绒藜种群Ⅰ(华北驼绒藜+小叶锦鸡儿+短花针茅+多根葱群落)和种群Ⅱ(华北驼绒藜+大针茅+冷蒿+糙隐子群落)半变异函数曲线为球状和高斯模型,空间分布格局为聚集型,种群较稳定;种群Ⅲ(华北驼绒藜+大针茅群落)和种群Ⅳ(华北驼绒藜+羊草+杂类草群落)半变异函数曲线为线形,空间分布格局为随机型,种群呈增长型.对种群分布格局形成有重要影响的15个环境因子的主成分分析表明,群落总盖度、华北驼绒藜种群密度、驼绒藜种群分盖度、坡度、土壤速效氮、土壤速效磷、年平均降雨量和人为干扰度是影响种群分布格局形成的最重要因素. 相似文献
9.
旨在探究秦岭草本植物群落种间关联性。通过野外60个样方对太白县咀头镇黄凤山村地区30种草本植物,测定χ 2检验、联结系数(AC)、Ochiai种间关联度指数(OI)等指标。结果表明：在由30个植物物种两两组合而成的435个种对中,AC结果中显著负关联的有301个;OI的结果显示弱联结(0≤OI<0.5)的物种对数是较强联结(0.5≤OI≤1)的5.80倍;χ 2联结性检验的结果显示,负关联和无关联的种对数分别占总种对数的21.15%和76.78%。综上所述,该地区的草本植物物种间独立性较强,群落整体处于不稳定状态,仍处于演替阶段。 相似文献
10.
运用方差比率法（VR）、X2检验、种间共同出现百分率（PC）和联结系数（AC）分析了贵州省六盘水市玉舍国家级森林公园十齿花群落20个优势灌木种群的种间联结性。总体关联度检验显示：20个灌木种群构成的190个种对总体上表现为显著的正关联。几项关联检验指标对十齿花群落主要灌木种群之间联结性关系检测结果表明：共同出现百分率PC和联结系数AC反映出的显著关联及完全独立的种对数均比用X2检测所得的种对数多,尤其是显著负联结的种对较为明显,但几种方法检验的结果总体上反映了大致相同的联结趋势;在总的种对数中,正联结种对数略多于负联结,呈显著和极显著关联以及完全独立的种对数所占比率较低,多数种对联结性不显著,趋于独立。 相似文献
11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
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
18.
[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
19.
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
20.
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