前言牧草类的品种一般用种子流通,遗传资源的保存形态几乎都是种子。但大多数牧草是异交植物,因属遗传性杂合,故育成品种的母本和优良无性系等基因型必须用营养体保存。以往将营养体栽植在田间或钵中连续保存,但由于受到花叶病等病害或者蚜虫、螨等虫害的为害,故其维持非常困难,不断看 Foreword The species of forage are generally circulated with seeds, and the genetic resources are almost all preserved seeds. However, most forages are outcrossing plants. Due to their hereditary heterozygosis, genotypes such as maternal breeders and elite clones must be conserved with vegetative bodies. Conventionally, the vegetative body is planted in a field or in a bowl for continuous preservation. However, the vegetative body is harmed by diseases such as mosaic diseases or by pests such as aphids and mites, and it is very difficult to maintain