属间杂交的

Nigra, B. oleracea and B. carinata belonged to class 2A according to the classification of karyotypes by Stebbins (1971). According to Levitzky's and Stebbin's view, the more asymmetric karyotype a species has, the more evolved it is. Therefore, B. campestris is the furthest evolved species among the elementary species, and B. juncea and B. napus the furthest among the amphidiploid species. Compared with the previous reports, there is no any cytoplasm in the chromosome sample prepared using this protocol which is very useful for the karyotype analysis, as well as the FISH research on Brassica species.

对上述研究结果分析表明：（1）芸薹属复合种是由基本种相互杂交而成；（2）B基因组与A或与C基因组亲缘关系较远，而A和C基因组亲缘关系较近；（3）芸薹属复合种在演化过程中，发生了染色体结构上的重排现象；（4）芸薹属复合种演化过程中，rRNA基因位点发生了减少；所获结果与国外同类报道相比表明：国内的白菜型油菜存在新的rRNA基因位点，即rRNA基因在芸薹属同一物种不同的品种间具有多态性；有关这类研究国内尚未见报道。

The self-fertile trigeneric hybrids between Triticum aestivum L.(2n=6x=42;AABBDD) and Agropyron michnoi Roshev.(2n=4x=28;PPPP) F1 hybrid (CM,2n=5x=35,ABDPP)with two rye (Secale cereale L.,2n=2x=14;RR)cultivars, Wugong 774 and AR132 were produced.

普通小麦(Triticum aetivum L。，2n=6x=42；AABBDD)和根茎冰草(Agrop yronmichnoi Reshev。，2n=4x=28；PPPP)间的F1杂种(2n=5x=35；ABDPP)与两个黑麦(Secale cereale L。， 2n=2x=14；RR)品种杂交，产生了自交可育的三属杂种。

Bidens pilosa var. radiata, one of the rapid expanding invasive weeds, has become prevailing throughout Taiwan. A study on the result enhanced by the breakdown of geographic isolation with the native varieties in genetic variation, population structure and introgressive hybrization is really in need. In this study the genetic variation and population structure among the varieties of Bidens pilosa complex were studied using ISSR markers.

在台湾Bidens pilosa种群在外部形态及分布上均非常类似，加上大花咸丰草又属极具侵略性的新归化种，在与其他自生变种又无明显隔离下，是否增加种间之交流与渐渗杂交之机会及对族群结构的影响，实有深入探讨之必要。

In addition, the authors suggest:① The research of firs hybridization should be carried out on a large scale in China;② In hybridization, the phylogeny of Abies must be considered, and we should put emphasis on the intro-section hybridization;③ The research on the strobili phenology of firs can ensure the hybridization succeed;④ The research is also important for the hybridization to study the genetic diversity of Abies;⑤ We can use the biotechnology and the knowledge of modern molecular biology to overcome the difficulties of breeding.

作者对我国开展这项研究提出了几点看法：①应大力开展我国冷杉树种间，以及与国外冷杉树种间的杂交研究；②杂交时必须考虑种的系统关系学并以派内杂交为主导方向；③对我国冷杉属树种进行开花结实习性研究；④开展我国冷杉属树种的系统学和遗传多样性研究；⑤结合现代生物技术和分子生物学知识，克服常规杂交中的困难。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。