抗丛枝病泡桐表型单株选择及其育种技术

Single-trunk of a tree selecting for resistance to witches'-broom disease of paulownia and breeding technique

为了选育出对丛枝病具有高抗性的泡桐品种,以四旁绿化林、人工林、天然分布林以及品种园的236株泡桐为对象,筛选出抗丛枝病泡桐单株,对其叶毛类型进行观察,并根据叶毛特征对其子代进行苗期抗病性选择。结果表明,泡桐叶毛类型与其对丛枝病的抗性密切相关,具有稠密长柄树状毛、长柄叉状毛和长柄大腺细胞腺毛的植株对丛枝病有高抗性,其抗病原因是抗传媒介体昆虫。对选出的抗丛枝病单株,分别用其根和种子进行繁育试验。根繁试验结果表明,感丛枝病单株根繁育的苗木,第6年全部感染丛枝病,抗丛枝病单株繁育的苗木至今仍未发病;种子繁育试验结果表明,在苗期可根据抗丛枝病母树与子代苗期叶毛特征的相关性进行抗病性选择,且选择的准确性达86%以上。用该方法选择出的苗木可直接用来造林,同时也可采集抗丛枝病母树的部分根繁殖成无性系,不仅缩短了育种周期,而且还克服无性系育种技术导致的遗传基础越来越窄的缺点。

In order to select variety of panlownia against witches＇ broom disease, single-trunk of a tree of panlownia with resistance to disease had been selected with 236 trunk of panlownia tree in greening stand of the four sides and artificial stand and nature stand and variety garden as subjects types of trichomes according to the characteristic of trichomes on the leaves at seeding period. The result showed,the types on the leaf-surface of the genus paulownia had close relation to witches＇-broom disease resistance. It was high resistant when the trachomes were dense dendroid with long stalk and forked trachomes and big glandular cell. The cause of disease resistance might be resistant against insect vectos. Root and seed with port of single-trunk of a tree resistame diease was tested. The result showed rootbreeding plants was infected with withes＇-broom disease in the sixth year,root of single-tunk of a tree with resistance disease breding plants hitherto was not infected with witche＇s-broom disease. Open pollinated seed had been bred,which were single-trunk of a tree with resistance,then resistance disease was selected in proge- nies by the seedlings＇ types of trichomes on leaf-surface which are correlative with the seed trees＇ types of trichomes. The result showed this method had above 86% accuracy. Selected seedlings by using this method would be planted. Meantime clone would be bred with root of seed tree. This breeding technique not only would shorten breed cycle but also was monoclonal paulownia culture characterized by a progressively decreasing genetic base which is primarily of exotic origin.