摘要
构建遗传图谱是当前生物学研究领域中的一个热点，进行图谱构建，林木与作物既有共性，又有各自的特点。因为进行图谱构建一是要有合适的分离群体，二是要有能揭示亲本多态性的遗传标记。两者可利用的遗传标记是一样的，但在进行作图群体构建时却存在一定差异，林木的遗传组成高度杂合，大多数林木为长期异交的树种，一般都有自交不亲合和近交衰退现象，象作物那样利用近交系或其它的高世代群体进行遗传图谱构建是不太可能的。由于研究方法的不同，以前的林木育种工作者很少留意建立和保存谱系清楚的Ｆ_２和ＢＣ_１群体，由于林木生命周期很长，建立这样一些高世代的群体也需要很长的时间，而且除了杨树、柳树等一些可在温室内水培杂交的物种，大多数林木的控制授粉杂交操作也是很困难的。因此研究过程中，等待材料的问题成为目前林木遗传图谱构建的主要限制因子之一。如何利用现成的材料和低世代群体，对林木遗传图谱构建工作的广泛开展具有重要意义。下面就这一问题作一些理论上的探讨和分析。
Most linkage maps in plants have been obtained from segregating pedigree derived from crossesbetween inbred lines. Such pedigrees or even three--generation pedigrees are generally not available intrees and are difficult to obtain due to a significant genetic load and time constraints. To incorporatemolecular marker assisted strategies into forest tree breeding, it is imperative to explore alternative approaches for the construction of linkage maps that make use of pedigrees already existing and commonlygenerated in tree breeding programs. Forest tree has a high heterozygosity, so the FI progeny is a segregating pedigree. When analysed with dominant markers, such as RAPD markers, many single dosedominant markers will be heterozygous in one parent, null in the other and therefore segregate 1:1 intheir FI progeny following a testcross configuration. This essay proPOse the combined use of dominantmarkers and FI progeny as a strategy for the construction of genetic linkage map of both parents(fullsib)or of the maternal tree(half sib) in forest trees as well as in any highly heterozygous sexually reproducing living organism. The optimizing experiment protocol is suggested and the theory basis of this strategy is discussed in detail.
出处
《生物工程进展》
CSCD
1996年第4期12-16,共5页
Progress in Biotechnology
