杂种的

Two signals of 45S rDNA were mapped on the mitotic metaphase chromosomes in the F1 hybrids, respectively, and one signal was present on a bivalent during meiotic of synaptene, diakinesis, and metaphase I. We inferred that the two mitotic chromosomes carrying 45S rDNA were homolo-gous pairs.

在有丝分裂中期染色体上2个杂种分别检测到2个杂交信号，在减数分裂粗线期、终变期、中期Ⅰ染色体上45S rDNA位于一个二价体上，说明这两个杂种携带45S rDNA的染色体为同源染色体。

The hybrid with genetic mark of narrow sense is considered as the hybrid which is of the most utilization value and meaning in four hybrids with genetic marks (broad sense,narrow sense,dominancy and recessive).

在广义、狭义、显性及隐性4种遗传标记杂种中，最有利用价值和意义的是狭义遗传标记杂种。

The utilization of heterosis and study on mechanism of heterosis are hotpoints in ricegenetics and breeding.

杂种优势利用和杂种优势机理研究是当前水稻生产和理论研究的热点。

In crosses of B. napus×B.carinata, the hybrid endosperm developed unsuffic-iently and became cellular precociously, the hybrid embryo developed slowly and stopped at the heart or torpedo stage after exhausting the precociously developed endosperm tissue.

在甘蓝型油菜×埃塞俄比亚芥中，杂种胚乳不甚发育并提前形成细胞，杂种胚发育缓慢，消耗早育的胚乳组织后便停滞在心形期或鱼雷形期。

F1 hybrid has the morphological feature which is between the male and female parents and shoed strong heterosis, exuberant vitality, late ripe period and low rate of self-fertility. The average chromosome configuration of F1 in PMC MI was 18.58Ⅰ+18.59Ⅱ+0.085Ⅲ+0.028Ⅳ. At anphase Ⅰ in PMC, some laggard chromosomes arranged in equatorial plate. Micronucleus and a lot of abnormal cells can be observed at dyad, tetrad and microspore.

杂种F1形态特征介于双亲之间，具有较强的杂种优势，生长旺盛，熟期晚，自交结实率较低。F1花粉母细胞减数分裂中期Ⅰ平均染色体构型为18.58Ⅰ+18.59Ⅱ+0.085Ⅲ+0.028Ⅳ，PMC后期Ⅰ观察到部分落后染色体排列在赤道板上；二分体、四分体和小孢子时期，细胞内普遍观察到微核，且出现大量异形细胞。

The contribution of the 5 main factors to total variation of population studied accounted for 86.84%.

遗传距离与杂种优势的关系较为复杂，并非遗传距离越大杂种优势越明显。

According to the performance of grain yield,these 10 QPM inbreeds could be divided into 4 heterotic groups.

根据杂交组合产量性状的配合力分析，可初步将这10个优质蛋白玉米自交系划分为4个杂种优势群和4种杂种优势模式。

The rate of maize yield growth has being declining due to narrow genetic background and limited new heterotic patterns since 1970s.The role of tropical and subtropical maize germplasm in maize improvement was discussed in this paper.

但70年代以来我国玉米增产率呈下降趋势，玉米生产一直处于徘徊状态，其主要原因是国内种质资源匮乏，缺乏新的杂种优势群和杂种优势模式。

Somatic hybrids grew weakly and took roots hard. By continuous subculture to facilitate to take roots using rhizogenic medium, the regenerants was transplanted on the cropland and backcrossed using cultivar wheat pollen.

体细胞杂种生长势差，生根困难，通过不断地使用生根培养基促进生根，然后移栽到大田中，利用不同播期的小麦花粉回交杂种，获得回交后代。

Sour orange and sweet orange may be the hybrid of pummelo and mandarin.

6根据胞质基因组的差异和聚类分析的结果对一些生物型的起源进行了分析，得出如下一些结论：葡萄柚是柚与甜橙的杂种，可能是与柚的回交种；本研究所包括的两个来檬生物型，其中之一的起源与枸橼、柚和澳洲指橘有关，另一个被误认为是枸橼的来檬生物型最后被认定为墨西哥来檬，来源与大翼橙和枸橼有关；粗柠檬是枸橼与宽皮橘的杂种；红黎檬可能是宽皮橘与粗柠檬的杂种；酸橙和甜橙为柚与宽皮橘的后代。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。