胚

While doing the RFLP tagging of giant embryogene,the genome changebetween mutants and its original parent,the relationship between RFLP andheteroses in indica,japonica and intermediate rice,the performance of multipleand null allelism in rice varieties,the utilization of null allelic RFLP probes inidentifying indica and japonica rice specifically,the distribution of the nullallelic RFLP probe RG684 in rice cultivars,and the segregations of RFLPmakers in indica/japonica F2 population were also studied.

本实验从经典遗传、分子遗传、育种潜力评估、育种新品系选育等领域，对巨大胚、甜胚乳、暗胚乳三种新型突变体进行了全面系统研究。在对巨大胚进行分子定位过程中，对涉及到的突变体与原始亲本基因组变化，籼、粳、中间型材料的RFLP多态性与杂种优势之间关系，水稻品种的复等位、零等位表现，鉴定籼、粳特异性的零等位RFLP标记，零等位标记RG684在稻种中分布，RFLP标记在籼粳交F2群体中分离等遗传现象也一并进行了分析。

An embryo at the stage following the blastula, consisting of a hollow, two-layered sac of ectoderm and endoderm surrounding an archenteron that communicates with the exterior through the blastopore.

原肠胚一种囊胚之后的胚胎，含有中空、两层的外胚层和内胚层，包围着通过胚孔跟外界交流的原肠

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cytoplasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methylation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribution of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cyto-plasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methy-lation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribu-tion of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastcysts fellowed by fusion of cytoplasm and nucleus and cleavage in vitro.After fusion of cytoplasm, the DNA methylation levels of the fused embryos was very high as well as two-cell diploid embryos in vivo.Then the embryos was rapiddly demethylated when the nucleus begin to fuse, resulting the lowest DNA methylation levels when the nucleus fused completely.After that, the DNA methylation levels of fused embryos were gradually increased until the blastocysts stage.However, whereas an asymmetric distribution of DNA methylation was established in an vivo-derived blastocysts with a higher methylation level in the inner cell mass than in the trophectoderm, in most vitro-derived tetraploid blastocysts, we can not detect the asymmetric distribution.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在囊胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

So worked resistance decrease of grafted cucumber.Grafted cucumber and squash root exudates have the inhibitory effect of germination of cucumber, elongation of root and hypocotyls, and have the same effect on squash.

南瓜和嫁接黄瓜根系分泌物对黄瓜发芽率，胚根胚轴的伸长均具有明显的抑制作用，这种抑制效果与浓度呈正相关；对南瓜发芽率及其胚根胚轴伸长的抑制也达到显著水平，这种抑制效果与浓度同样呈正相关。

The method is based on a genetic model containing both the direct effects and maternal effects of an endosperm QTL and on an experimental design termed two-stage hierarchical design, in which the trait information is obtained from F3 endosperms and molecular marker information is obtained from F2 plants and F3 embryos.

文章提出了包括胚乳效应和母体效应的胚乳性状QTL定位的统计方法，该方法的实验设计是分子标记基因型信息来自F2母体植株和F3种子胚，胚乳性状表型值来自F3单粒种子胚乳，称之为两步等级设计。

Forward and reverse subtractive cDNA libraries were constructed using suppression subtractive hybridization method,using 10 DAP and 20 DAP endosperms of the two inbreds.The four subtracted cDNA libraries enriched gene expressed specifically or at higher level in early stage and middle stage of endosperm development for N04 and Dan232,respectively.

利用抑制差减杂交方法，分别构建了自交系N04和丹232 10 DAP和20 DAP胚乳的正反向4个抑制差减杂交库，分别富集了N04胚乳早期、N04胚乳中期、丹232胚乳早期和丹232胚乳中期增强表达的基因。

Embryoides occurred from exterior of callus and developed through the stages of globular embryoid,heart shaped embryoid,tin fish-shaped embryoid and cotyledon differentiation stage embryoid.

胚状体为外起源发生方式，经球形胚、心形胚、鱼雷形胚、子叶形胚等阶段发育成熟。

When cultured on the medium with different auxin , root segments could elongate and branch, and the addition of 1mg/l IBA into the medium was the most suitable for long-term root culture. Calli could be induced from root explants in the presence of 2, 4-D and when transferred onto E medium, they transformed further into embryonic calli which could develop into normal plants through the stages of globular-embryo, heart-shaped embryo, torpedo-shaped embryo, cotyledonary embryo.

培养基中添加生长激素（IAA，IBA，NAA）能够诱导无菌苗根切段的生长和分枝形成；而1mg／l IBA的存在，最适合于根的长期离体培养。2，4-D的存在能够诱导根外植体脱分化形成愈伤组织，愈伤组织转移至E型分化培养基能够转变成胚性愈伤组织，并进一步经球形胚、心形胚、鱼雷形胚、子叶形胚发育成正常植株。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失