杂交育种

Determination of combining ability was one effective way to select excellent parents and make excellent cross combinations in breeding of Antheraea pernyi.

配合力测定是柞蚕育种中选择优良亲本和组配优良杂交组合行之有效的方法之一。

Diallel analysis has been broadly used as an important tool of genetic analysis in classical quantitative genetics, which advanced the development of genetics studies and breeding practices.

双列杂交分析是经典数量遗传学中应用最为广泛的一种重要的遗传分析方法，推动了遗传研究与育种实践的发展。

Basing on our early stage research work about collection and description of sugarcane germplasm and the aided project of Yunnan Natural Science Fund (2001 C0015Q), the wild species Erianthus fulvus, which has good characters, cold-resistant, drought-resistant, higher Brix and less chromosome number, was utilized for the first time through intergeneric hybridization with sugarcane cultivar. Its F_1 hybrids were appraised with some new techniques and methods for germplasm enhancement.

本研究在课题组考察采集和保育鉴定甘蔗野生种质资源的前期工作基础上，依托云南省自然科学基金资助项目(2001C0015Q)，首次利用具有特异优良性状(抗旱、耐寒、锤度高、染色体数目少)的蔗茅野生种与甘蔗栽培种或品种进行属间远缘杂交，扩大甘蔗遗传多样性；采用新技术、新方法对蔗茅杂种F_1代材料进行早期鉴定评价研究，筛选具有育种价值的新种质，为进一步选育生态适应性广、抗逆性强、丰产高糖的甘蔗新品种奠定物质基础。

Graminaceae ; Tissue culture: Regulation of gene expression ; Micropropagation ; Gremplasm conservation ; Crop breeding ; Somatic hybrization ; Gene transfer techniques ; Plant genie engineering

禾本科植物；组织培养；基因表达的调控；无性系繁殖；种质保存；作物育种；体细胞杂交；基因转移技术；植物基因工程

The choice characters set up by regression and path analysises did not only provide basis ofchoice of charater for hydrid parent plant and hydrid progeny of rice but also opened a brightfuture for the application of computers in high-yield breeding.

回归和通径所确定的选择性状不仅可以作为对水稻杂交亲本及其杂种后代的性状选择依据，提高其选择效果，同时也为计算机在水稻高产育种中的应用开辟了广阔的前景。

So it is very necessary to study variances of Chinese Meretrix meretrix germplasm resources and their molecular genetic bases for their lasting utilization,sustained and healthy development of aquaculture industry. In this study, the genetic bases and their variances of representative populations of Meretrix clam were investigated through phenotypic traits and on the molecular level by quantitative genetic methods and molecular marker analysis technique.

本研究从表观性状和分子水平上探测我国文蛤种质资源的遗传基础和变异水平，旨在深入了解我国文蛤的种质状况并为其保护和可持续利用提供依据；在此基础上，通过杂交选择育种实践，分析和探讨文蛤由此获得杂种优势水平，为养殖文蛤的遗传改良和新品种培育提供理论指导。

Interspecies hybridization and backcrossing is a means to transfer desirable genes from one species to another in breeding programs of higher plants. Monosomic alien addition lines can be produced via addition of single chromosome of an alien donor species to the entire chromosome complement of the recipient species.

在高等植物中，以种间杂交和回交把有益基因从一个物种转移到另一个物种为目的育种项目中，单个外源染色体常常被附加到含有受体细胞完整一套染色体中，形成异源单体附加系。

The new plant type Indica and Japonica varieties showed somewhat check heterosis whencrossed with one of the four sterile lines. America Japonica varieties showed few fillers andlower seed set ratio and Africa Japonica varieties, Nuda varieties, Javanica varieties have fewtillers and taller plant height, so they could not be used directly in Japonica hybrid ricebreeding program.

美国稻的分蘖少且结实率较低，产量优势不大；非洲稻的分蘖少，实粒数也少，株高太高，无法直接利用；新株型粳稻与培矮64s、N422s配组有一定的优势，新株型籼稻与N422s、108s配组的优势也较大，在华北两系杂交粳稻育种中也有一定的利用价值；光壳稻和爪哇稻的株高偏高，无法直接利用，可间接利用这两个生态型千粒重大的特点。

In laboratory,"Pearl oyster breeding scheme, POBs" assumes populations of Indian and Sanya as the basic groups to nurture specialized lines, and then constructs cross lines by making use of heterosis and eventually bring out new varieties of P.martensii.

在我们实验室的&珍珠贝育种规划(Pearl oyster breeding scheme， POBs)&，就是以印度种群和三亚种群作为基础群，分别培育专门化品系，利用杂种优势，构建杂交配套系，最终育成马氏珠母贝新品种。

The mechanism of triploid seedlessness, evaluation approaches of triploid grapes and embryo rescue technique are also discussed. Seven newly bred triploid seedless cultivars in the world are briefly described such as Yileyi, King Dela, Honey Seedless, Kai Mi...

简要介绍了国内外育成的7个三倍体无核葡萄新品种尾玲、戴拉王、蜜无核、美嶺、夏黑、无核早红和马格拉契的特征特性，并讨论了三倍体无核葡萄育种存在问题和未来的研究重点如杂交亲本的选择、三倍体杂合胚的发育特点和无核性状的遗传规律等。

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％。