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排序方式: 共有135条查询结果,搜索用时 31 毫秒
41.
两种常绿杜鹃亚属幼苗耐热性的主成分及隶属函数分析 总被引:1,自引:0,他引:1
以常绿杜鹃亚属(Rhododendron subgenus Hymenanthes)的井冈山杜鹃(R.jinggangshanicum Tam)、猴头杜鹃(R.simiarum Hance)4年生实生苗为材料,在人工气候箱中模拟高温试验,测定不同温度下叶片的丙二醛(MDA)、过氧化氢(H2O2)、脯氨酸(Pro)、可溶... 相似文献
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无花果亚属隶属于桑科,既是重要的水果资源,也是优良的中药资源,广泛种植于热带、亚热带地区,因含有丰富的生物活性成分和保健功效,经济价值突出。无花果亚属植物中异戊烯基类黄酮含量丰富,结构多样,已报道有37种异黄酮、2种黄烷酮、7种黄酮和1种查尔酮。无花果异戊烯基类黄酮具有突出的抗氧化活性,能够缓解更年期症状,保护骨骼、预防炎症、预防癌症等。从化学结构和生物活性两方面对无花果亚属植物的异戊烯基黄酮类化合物的研究概况进行总结,以期为该属植物的开发和利用提供参考。 相似文献
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The efficiency of any plant regeneration system lies in part in its wide applicability to diverse genotypes. In Asiatic Vigna, cotyledon and cotyledonary node explants from 4-day-old seedlings of 27 genotypes were cultured in a medium consisting of
MS salts, B5 vitamins, 3.0% sucrose and 1.0 mg l-1 BA. Direct and efficient multiple shoot regeneration (80–100%) from the cotyledonary nodes was obtained in all epigeal species
namely radiata, mungo, aconitifolia, subspecies radiata var. sublobata, mungo var. silvestris and in the hypogeal but allotetraploid glabrescens. In contrast, two other hypogeal species V. angularis and V. umbellata failed to initiate shoots from the nodes. However, adventititious shoots developed at the basipetal cut (hypocotyl) in 35–67%
of V. angularis explants. These results provide evidence in support of the existing genomic grouping within subgenus Ceratotropis, which designates AA, A1A1 and A1A1/- to epigeal, hypogeal and the allotetraploid species, respectively. Mean shoot production ranged from 3.3 to 10.4 shoots
per explant during the first subculture and varied significantly among the responsive genotypes within 4 species. Additional
shoots were obtained in all genotypes after subsequent subculture. However, cotyledons were not as regenerable as cotyledonary
node explants. Although significant differences in rooting were observed among the shoots of the 15 genotypes, the response
was generally higher in MS basal medium (MSO) than in MS with 1.0 mg l-1 IAA. Regenerated plants were successfully transferred to soil (50–100% survival rate) and all surviving plants were reproductively
fertile.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
45.
记述中国颊脊隐翅虫属Quedius二点颊脊隐翅虫亚属Microsaurus和一点颊脊隐翅虫亚属Raphirus 3新种,李氏二点颊脊隐翅虫Quedius(Microsaurus)lii sp.nov.,肖氏二点颊脊隐翅虫Quedius(Microsaurus)xiaoae sp.nov.,和粪一点颊脊隐翅虫Quedius(Rphirus)coprobius sp.nov..李氏二点颊脊隐翅虫至今未归入任何种群,可能代表一个新群,肖氏二点颊脊隐翅虫隶属二点颊脊隐翅虫亚属的穆柯颊脊隐翅虫群mukuensis,粪一点颊脊隐翅虫为一点颊脊隐翅虫亚属的里颊脊隐翅虫群intricatus的成员. 相似文献
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Allium subgenus Melanocrommyum (Alliaceae) from Eurasia comprises about 150 mostly diploid species adapted to arid conditions. The group is taxonomically complicated with different and contradictory taxonomic treatments, and was thought to include a considerable number of hybrid species, as the taxa show an admixture of assumed morphological key characters. We studied the phylogeny of the subgenus, covering all existing taxonomic groups and their entire geographic distribution. We analyzed sequences of the nuclear rDNA internal transcribed spacer region (ITS) for multiple individuals of more than 100 species. Phylogenetic analyses of cloned and directly sequenced PCR products confirmed the monophyly of the subgenus, while most sections were either para- or polyphyletic. The splits of the large sections are supported by differences in the anatomy of flower nectaries. ITS data (i) demand a new treatment at sectional level, (ii) do not support the hypotheses of frequent gene flow among species, (iii) indicate that multiple rapid radiations occurred within different monophyletic groups of the subgenus, and (iv) detected separately evolving lineages within three morphologically clearly defined species (cryptic species). In two cases these lineages were close relatives, while in Allium darwasicum they fall in quite different clades in the phylogenetic tree. Fingerprint markers show that this result is not due to ongoing introgression of rDNA (ITS capture) but that genome-wide differences between both lineages exist. Thus, we report one of the rare cases in plants where morphologically indistinguishable diploid species occurring in mixed populations are non-sister cryptic species. 相似文献
48.
S. Takamatsu H.-D. Shin U. Paksiri S. Limkaisang Y. Taguchi N. Thi Binh Y. Sato 《Mycoscience》2002,43(4):0333-0341
Serious outbreaks of powdery mildew by a fungus belonging to the mitosporic genus Oidium subgenus Pseudoidium have been reported on soybean (Glycine max) in a wide area of eastern Asia since 1998. The taxonomic and phylogenetic placement of the causal fungus has not yet been
determined because of lack of the perfect stage. We found ascomata having mycelioid appendages on a single leaf of soybean
infested by powdery mildew. Molecular phylogenetic analysis was conducted based on a total of 14 sequences of the rDNA internal
transcribed spacer (ITS) region from 13 soybean and wild soybean (Glycine soja) materials collected in Japan, Korea, Vietnam, and the United States, combined with 47 sequence data obtained from the DNA
databases. It was revealed that two Erysiphe species were associated with the outbreak of soybean powdery mildew. There was 16% difference between the two species in
genetic divergence of the ITS sequence. One species with perfect stage has an ITS sequence identical to that of Erysiphe glycines on Amphicarpaea and is identified as Erysiphe glycines based on the ITS sequence and morphology of ascomata. The second species, without the perfect stage, is likely to be Erysiphe diffusa (= Microsphaera diffusa), known as the fungus causing soybean powdery mildew in the United States, because the ITS sequences are identical to those
from materials collected in the United States. However, we need materials having ascomata of E. diffusa to confirm the species name.
Received: March 15, 2002 / Accepted: May 22, 2002 相似文献
49.
中国侧棘斑蚜属分亚属研究及五新纪录亚属(同翅目:蚜科:角斑蚜亚科) 总被引:3,自引:3,他引:0
研究认为中国侧棘斑蚜属Tuberculatus Mordvilko,1894蚜虫有7个亚属,刺棘斑蚜亚属Acanthocallis Matsumura 1917,东方棘斑蚜亚属Orientuberculoides Hille Ris Lambers,1974,针棘斑蚜亚属Acanthotuberculatus Quednau,1999,阿棘斑蚜亚属Arakawana Matsumura ,1917,日本棘斑蚜亚属Nippocallis Matsumura,1917,中日棘斑蚜亚属Nippotuberculatus Quednan,1999和肖棘斑蚜亚属Tuberculoides van der Goot,1915。给出分亚属检索素,并记述5个中国新纪录亚属和一个新纪录种环肖棘斑蚜Tuberculatus(Tuhberculoides)annulatus(Hartig 1841),研究标本存放在中国科学院动物所动物标本馆。 相似文献
50.