杂种性

It was deduced that epitasis also was one of the genetic factors to indica/japonica hybrid sterility.

标记的互作分析表明，籼粳杂种的育性除了主效基因的单独作用以外，位点之间的互作，即上位性也是一重要的遗传因素。

The trigerieric hybrid involving Triticum, Leymus and Thinopyrum has been created by the cross between Octoploid Tritileymus and Octoploid Tritithinopyrum, and the morphology, fertility and cytology of the F1 hybrids was studied.

利用八倍体小滨麦和八倍体小偃麦杂交，创制出小麦－滨麦－偃麦草三属杂种，对杂种F1进行了形态学、育性和细胞学分析。

Chromosome pairing behavior in meiosis of the hybrid F1 was carried out. Results showed that in an average , 1.25 rod bivalents were observed in one PMC, meiotic configuration was 2n=14=11.49Ⅰ+1.25Ⅱ(Xta=1.25) and most of PMCs possessed 1～5 bivalens, indicating that the relatively high homeology was detected between the D genome of Ae.tauschii and the V genome of D.villosum. The morphological differences between F1 hybrids and their parents were significant. F1 plants were highly self-sterile, but partially self-fertile after treated by chromosome doubling technique.

对杂种F1花粉母细胞减数分裂中期Ⅰ染色体配对行为进行观察发现，"节节麦×簇毛麦"杂种F1平均每PMC有1.25个棒状二价体，染色体的平均构型为2n=14=11.49Ⅰ+1.25Ⅱ(Xta=1.25)，大部分被观察的细胞出现1～5个二价体，表明节节麦D染色体与簇毛麦V染色体间具有相对较高的部分同源配对， D和V染色体之间存在一定的部分同源性。F1植株高度自交不育，经染色体加倍处理后能够自交结实。

Fromthese facts,It could be deduced that 8 to 14 pairs of chromosomes possessed a certaindegree of hetorology,which was directly groved to be hybrid origin of P.tomentosaaccording to the good chromosome homology and fertility of P.bolleana and thehybrids of P.tomentosa×P.bolleana,it could be further deduced that the original parentsof P.tomentosa involved probably P.bolleana or P.alba.

从终变期、中期I的染色体构型看，有数目不等的联会程度较差的单价体和棒状二价体出现，在后期I，甚至末期I亦可见到含落后染色体分裂相的细胞，由此推断可能有8~14对染色体表现出一定程度的异源性，鉴于新疆杨以及毛白杨与新疆杨杂交产生的杂种毛新杨的染色体同源性较强、育性较好等现象，进一步推断毛白杨起源亲本可能包括新疆杨或银白杨。

But to make good use of them, their genetic characteristics and germplasm relationship with Chinese inbred lines representing different heterotic groups should be studied.

本研究采用传统的配合力和杂种优势分析与现代的SSR分子标记技术相结合的方法，探讨引进南斯拉夫玉米自交系与我国不同优势类群骨干自交系的配合力、杂种优势、遗传距离和杂合性，为引进自交系的高效合理利用提供理论依据；并通过各项遗传指标与F1产量的相关分析，探讨各项指标预测杂种优势的可行性和效果。

In this study, through the traditional methods, analysis of combining ability and heterosis, and modern SSR marker technique, the combining ability, heterosis, genetic distance and heterozygosity between introduced Yugoslavia inbreds and important lines representing different heterotic groups in our country were studied, which will greatly influence to make full use of those indroduced lines.

本研究采用传统的配合力和杂种优势分析与现代的SSR分子标记技术相结合的方法，探讨引进南斯拉夫玉米自交系与我国不同优势类群骨干自交系的配合力、杂种优势、遗传距离和杂合性，为引进自交系的高效合理利用提供理论依据；并通过各项遗传指标与F1产量的相关分析，探讨各项指标预测杂种优势的可行性和效果。

To study the molecular mechanism of Larix somatic embryogenesis, a differentially expressed cDNA library of Larix somatic embryo in the period of maturation was constructed using suppression subtractive hybridization. The cDNA from the cultures at the stage of somatic embryo maturation of embryogenic cell line Y35 of L. leptolepis ×L. principis-rupprechtii was used as the tester and the cDNA from its subcultured callus was used as the driver. Eight hundreds randomly selected positive clones were sequenced, and 468 UniGenes were obtained finally.

为研究落叶松体细胞胚胎发生的分子机理，文章以日本落叶松×华北落叶松杂种无性系胚性细胞系Y35体细胞胚成熟阶段培养物的cDNA为实验组，继代培养阶段胚性愈伤组织的cDNA为对照组，利用抑制性消减杂交技术(Suppression subtractive hybridization， SSH)构建了体细胞胚成熟阶段的差异表达基因文库。

To study the molecular mechanism of Larix somatic embryogenesis, a differentially expressed cDNA library of Larix somatic embryo in the period of maturation was constructed using suppression subtractive hybridization. The cDNA from the cultures at the stage of somatic embryo maturation of embryogenic cell line Y35 of L. leptolepis L. princi-pis-rupprechtii was used as the tester and the cDNA from its subcultured callus was used as the driver. Eight hundreds ran-domly selected positive clones were sequenced, and 468 UniGenes were obtained finally.

为研究落叶松体细胞胚胎发生的分子机理，文章以日本落叶松华北落叶松杂种无性系胚性细胞系Y35体细胞胚成熟阶段培养物的cDNA为实验组，继代培养阶段胚性愈伤组织的cDNA为对照组，利用抑制性消减杂交技术(Suppression subtractive hybridization， SSH)构建了体细胞胚成熟阶段的差异表达基因文库。

To study the molecular mechanism of Larix somatic embryogenesis, a differentially expressed cDNA library of Larix somatic embryo in the period of maturation was constructed using suppression subtractive hybridization. The cDNA from the cultures at the stage of somatic embryo maturation of embryogenic cell line Y35 of L. leptolepis × L . princi-pis-rupprechtii was used as the tester and the cDNA from its subcultured callus was used as the driver. Eight hundreds ran-domly selected positive clones were sequenced, and 468 UniGenes were obtained finally.

为研究落叶松体细胞胚胎发生的分子机理，文章以日本落叶松×华北落叶松杂种无性系胚性细胞系Y35体细胞胚成熟阶段培养物的cDNA为实验组，继代培养阶段胚性愈伤组织的cDNA为对照组，利用抑制性消减杂交技术(Suppression subtractive hybridization， SSH)构建了体细胞胚成熟阶段的差异表达基因文库。

Stuber et al.(1992) considered the overdominance is the major genetic basis of heterosis in maize; Xiao et al.(1995) suggested the dominance is the major molecular mechanism of heterosis in rice. Subsequently, Yu et al.(1997) and Hua et al.(2003) demonstrated the epistasis made the siginificant contribution to heterosis in rice.

Stuber等认为，超显性是玉米杂种优势形成的主要原因；Xiao等(1995)认为显性作用是水稻杂种优势形成的遗传基础，Yu等(1997)和Hua等(2003)认为上位性在杂种优势形成过程中起重要作用。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。