Development of easy system using molecular markers for identification of germplasm in forage crops.

在饲料作物中，各种种质（包括生态型、地方品种和育种品系）之间的遗传区分是非常困难的，因为它们的近交繁殖习惯和特殊的改良方法可能导致种质之间和种质内部存在广泛的遗传变异。应用分子标记技术对饲料作物遗传资源进行评价和鉴定是一种很有前途的方法。利用核基因组分子标记技术对种质资源进行鉴定分析。饲料用甜菜地方品种可通过同工酶位点的14个等位基因进行区分。利用随机选取的10个碱基对的引物进行RAPD，可以对饲用玉米各自交系进行鉴定。另一种花药培养系的方法仍然开放。在许多情况下，一种种质不能用核基因组分子标记来表征。与核基因组相比，细胞器基因组更加稳定，便于根据种质的系统发育关系对种质进行分类。通过3种限制性酶和6个线粒体基因探针的RFLP分析，将多年生黑麦草品种划分为系统发育上相互接近和相互独立的3种类型。大多数品种均属于这三种类型。在一些多年生黑麦草中发现了线粒体基因组多态性，但这可能是一种罕见的现象。在饲料作物中，利用分子标记开发easy系统，对种质资源进行了评价和分类，促进了新品种的选育。

In forage crops it is very difficult to distinguish genetically among various germplasms including ecotypes, landraces and breeding lines, because their outbreeding propagation habit and special method for improvement might cause to include a wide genetic variation between and within the germplasms. Application of molecular markers may be a promising method for evaluation and discrimination of genetic resources in forage crops.Some techniques for nuclear genome molecular markers were used to analyze for discrimination of germplasm. Fodder beet landraces could be distinguished by 14 alleles of isozyme loci. RAPD by PCR of a few random primers with ten base pair could identify each inbred line of the forage corn. A method for anther culture line remains open.There are many cases that a germplasm can not be characterized by nuclear genome molecular markers. Compared with nuclear genome, organelle genome may be stable and convenient to group the germplasms in accordance with their phylogenetic relation. RFLP by 3 restricted enzymes and 6 mitochondria gene probes could classified the perennial ryegrass cultivars into three types, which are phylogenetically close to each other, and other ones. Most of the cultivars belonged equally to the three types. Mitochondria genome polymorphism within-cultivar was observed in some perennial ryegrass, though it may be a rare phenomenon.In forage crops Development of the easy system using molecular markers made the evaluation and classification of the germplasms and will promote to raise a new cultivar.