杂种优势的

The average heterosis of the grain yield per plant is 75. 79%, 57. 67% and 12. 55% in the hybrids of the common wheat with spelt wheat, club wheat and itself respectively. the heterosis degree of the interspecific hybrid was greater than that of intervarietal hybrid.

普通小麦与斯卑尔脱小麦的种间杂种每株产量的平均杂种优势为75.79%，普通小麦与密穗小麦的种间杂种每株产量的平均杂种优势为57.67%，普通小麦品种间杂种每株产量的平均杂种优势为12.55%，种间杂种优势大于品种间杂种优势。

The average heterosis of spike number per plant and 1 000-grain-weight were high and obviously related to yield heterosis at 0. 01 and 0. 05 level, respectively; the average yield heterosis of F1 hybrids between common wheat and club wheat was 77. 19%(ranged from-2. 18% to 143. 42%), the average heterosis of spike number per plant and spike grain number were high and both was also obviously related to yield heterosis at 0. 01 level.

结果发现：小麦种间杂种在产量上具有明显的杂种优势，其中斯卑尔脱小麦与普通小麦所配的30个种间杂交组合产量杂种优势平均为109.24%(43.14%～187.96%)，单株穗数及千粒重平均优势较大且与产量优势的相关分别达极显著水平和显著水平；密穗小麦与普通小麦所配的30个种间杂种的杂种优势为77.19%(-2.18%～143.42%)，单株穗数和主穗粒数优势较大且与产量优势的相关均达极显著水平。

The SCA effect was important in the heterosis of the spike number per plant of the intervarietal hybrid, the SCA and GCA were both important in the heterosis of the grain number of main spike of the intervarietal hybrid; the SCA effect played an major role in the heterosis of the spike number per plant of the interspecific crosses of the common wheat and club wheat, the SCA effect played an major role in the heterosis of the 1000-grain weight of the interspecific crosses of the common wheat and spelt wheat.

普通小麦品种间杂种每株穗数杂种优势中，特殊配合力所代表的非加性遗传效应起了主要作用，而主穗粒数杂种优势中一般配合力、特殊配合力所代表的加性、非加性遗传效应所起的作用相当；普通小麦与密穗小麦种间杂种主穗粒数杂种优势中特殊配合力所代表的非加性遗传效应起了主要作用；普通小麦与斯卑尔脱小麦间杂种千粒重杂种优势中特殊配合力所代表的非加性遗传效应起了主要作用。

Molecular systematics on germplasm resources of oak silkworm, Antheraea pernyi , including genetic diversity, cultivar taxonomy and microevolution within species, were investigated using Random Ampified Polymorphic DNA, mtDNA sequence analysis and population genetic analysis.

1.1.1 柞蚕的地理分布 20-211.1.2 柞蚕种质资源的收集、改良、保存和利用 21-231.1.3 柞蚕的滞育和化性 231.1.4 柞蚕的体色 23-241.1.5 柞蚕品种资源的系统分类 24-251.1.6 柞蚕杂种优势的利用研究 251.1.7 柞蚕的起源与传播 25-28

Genetic diversity among 46 rice clusters was studied using the AFLP molecular marker, and relationship between genetic distanceand hybrid performance in a diallel set of crosses between them was assessed.

利用AFLP分子标记对46个水稻品种进行遗传多样性分析，继而研究分子标记遗传距离与按照NC设计获得的195个杂交组合的产量及特殊配合力的相关性，探讨预测杂种优势的可能性。

The equations of heterosis areV(subscript F1)=(l/2)Na^2+(l/4)Nd^2+Vsubscript I(F1additive dominance F1 epistasisV=(1/2)Na^2+(l/2)V1,additive parental epistasisV=(1/4)Nd^2+Vsubscript I(F1+(1/2)Vl,dominance F1 epistasis parental epistasis.where N is number of genes controlling a trait,α=P(subscript i-P/2, d is deviation from midparent, while the variance components are all indicated by their names under the repective terms.

由一个二项分布随机变数及其推广至多项分布推导出杂种优势的公式：V(下标 F1)=Na^2/2+Nd^2/4+V下标(F1加性显性 F1上位V＝Na^2/2+V/2加性亲代上位V＝Nd^2/4+V下标(F1+V/2显性 F1上位亲代上位在此N=控制性状的基因数，α=p(下标 i-P/2， d=离中亲的偏差，而各方差则如方程底部所列。

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。

This paper studied relative characters and correlation of three ear leaf for 15 high combining inbred lines for select better inbred lines.studied that parents selected and mated,predicted heterosis.

通过对15个高配合力亲本自交系及其组配的8个杂交种棒三叶有关性状及相关性的研究，揭示优良自交系的特征，探索亲本的搭配，予测杂种优势的大小。

Major difference of gene expression occurred in the qualitative level, especially cross-fertilized kernel specifically expressed pattern.

对三个不同优势的小麦杂交种子和自交种子及其正反杂交种与其双亲种子发育前期基因表达研究表明，杂交种子和自交种子之间存在明显的基因表达差异，且以质的特异表达为主；不同优势的正反杂交当代种子与亲本间基因表达发生了显著的改变，进一步分析发现单亲表达与杂种优势存在一定的正向关系，而杂种沉默表达与杂种优势存在一定的负向关系。

He smashed the traditional concept about self-pollinating characteristic of crops, such as rice, that is they have no hybrid advantage.

他打破了水稻等&自花授粉作物没有杂种优势&的传统观念，在三系杂交稻、两系杂交稻的选育与推广及超级稻的研究等方面做出了开创性的卓越贡献。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。