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利用异源多倍体作为桥梁材料是克服远缘杂交障碍,创制新种质和进行品种改良的一种重要途径.本研究对已获得的大白菜(Brassica campestrisL.ssp.pekinensis (Lour.) Olsson)与结球甘蓝(Brassica oleracea var.capitata L.)种间异源四倍体和异源三倍体,利用形态学、解剖学、分子标记及细胞学等方法进行比较鉴定.研究表明,多倍体在植株形态、花器官和气孔大小等方面均表现出巨大性和超亲优势,其中四倍体比三倍体表现普遍更明显.多倍体的气孔密度显著的低于双亲.多倍体花粉生活力比双亲降低,四倍体花粉活力为81.56%,三倍体的花粉活力仅有18.78%.多倍体自交结实性明显低于双亲,四倍体自交结实率仅为0.28%;四倍体作为母本与大白菜杂交结籽率比其反交要高,是反交的2.11倍,以三倍体为母本或父本时与大白菜杂交,结实均非常低,且三倍体自交未获得种子.相关序列扩增多态性(SRAP)标记结果表明,多倍体中包含了双亲的遗传信息,但分f标记并不能区分四倍体与三倍体.细胞学观察显示,四倍体的染色体数目为2n=4x=38,三倍体的染色体数目为2n=3x=29.大白菜-结球甘蓝异源多倍体的鉴定为进一步大白菜品种改良和新种质的创制提供了基础资料.  相似文献   

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The domestication of cultivated flax (Linum usitatissimum L. subsp.usitatissimum) is briefly discussed. Using data documented as a matter of routine in genebank work, 63 accessions of cultivated flax from the flax germplasm collection of the Gatersleben Genebank are compared with 73 accessions of its wild progenitor pale flax (subsp.angustifolium (Huds.) Thell.), which have been observed in systematic field trials. Range of variation, genetically based variation, heritability and correlation of several characters are considered, especially with respect to the influence of domestication. Cultivated flax shows higher variation in the characters of generative plant parts, while pale flax varies more in the vegetative parts of the plant. The character correlations are similar in both subspecies. Of the 29 characters studied in pale flax the parameters describing tillering, height of plant, weight of seeds, width of petals and width of leaves are especially suitable for distinguishing between different accessions. In spite of the high heritabilities of most of the characters, the influence of the environment is significant in most cases.  相似文献   

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Hexane and ethyl acetate phases of the methanol extract of Macaranga monandra showed fungal growth inhibition of Colletotrichum acutatum, C. fragariae and C. gloeosporioides, Fusarium oxysporum, Botrytis cinerea, Phomopsis obscurans, and P. viticola. Bioassay-guided fractionation led to the isolation of two active clerodane-type diterpenes that were elucidated by spectroscopic methods (1D-, 2D-NMR, and MS) as kolavenic acid and 2-oxo-kolavenic acid. A 96-well microbioassay revealed that kolavenic acid and 2-oxo-kolavenic acid produced moderate growth inhibition in Phomopsis viticola and Botrytis cinerea.  相似文献   

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Cultivar Marion and Evergreen blackberry aromas were analyzed by aroma extract dilution analysis. Sixty-three aromas were identified (some tentatively) by mass spectrometry and gas chromatography-retention time; 48 were common to both cultivars, and 27 have not been previously reported in blackberry fruit. A comparison of cultivars shows that both have comparable compound types and numbers but with widely differing aroma impacts, as measured by flavor dilution (FD) factors. Ethyl 2-methylbutanoate, ethyl 2-methylpropanoate, hexanal, furanones (2,5-dimethyl-4-hydroxy-3-(2H)-furanone, 2-ethyl-4-hydroxy-5-methyl-3-(2H)-furanone, 4-hydroxy-5-methyl-3-(2H)-furanone, 4,5-dimethyl-3-hydroxy-2-(5H)-furanone, and 5-ethyl-3-hydroxy-4-methyl-2-(5H)-furanone), and sulfur compounds (thiophene, dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, 2-methylthiophene, and methional) were prominent in Evergreen (FD 512-2048). Except for ethyl 2-methylpropanoate, these same compounds were also prominent in Marion, but the FD factors varied significantly (FD 8-256) from Evergreen. The aroma profile of blackberry is complex, as no single volatile was unanimously described as characteristically blackberry.  相似文献   

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