甘蓝型油菜游离小孢子培养的胚胎发生

以生长在非控温控光下的４个冬性甘蓝型油菜（ＢｒａｓｓｉｃａｎａｐｕｓＬ．）品种为供体，进行游离小孢子培养。研究发现，多数品种在开花３－７天取材最为适宜。在甘蓝型油菜小孢子培养中只有单核晚期的小孢子才可能发育成胚状体，而花药培养时处于单核早期的小孢子易于发育成胚状体。在适当花期选取发育比较一致的单核晚期小孢子培养，经数小时后，部分小孢子便开始膨大，这是小孢子发育成胚的最早标志，膨大的小孢子中，有部分形成多细胞球并进一步发育成胚。用春性甘蓝型油菜为材料进行蔗糖浓度的实验结果表明：培养３天后，在１６％蔗糖培养基中存活的小孢子最多，达１６．１３％；培养３０天后，胚状体诱导频率则以１３％蔗糖浓度为最高，每花蕾可达１４４个胚状体。如果在１６％蔗糖培养基中培养３天后，添加等体积的１３％蔗糖培养基，能够大大提高胚状体的诱导频率，为仅用１３％蔗糖培养基培养的３．７倍。这一实验体系正在用于抗菌核病的诱变与筛选，并作为外源基因导入的实验体系。

Embryogenesis of Isolated Microspores of Brassica napus in Culture

The isolated microspores were cultured by using four winter varieties of Brassica napus growing under the uncontrolled conditions of temperature and light as donor. It was found that the period between third to seventh days was the best time for taking explant, while explants,taken beyond this period,gave no embryoids.In the microspore culture of Brasstica napus only those late-uninucleate microspores could grow into embryoids but in the anther culture,the early-uninucleated microspores tended to grow into embryoids.When the late-uninucleate microspores,developing synchronous were taken in the suitable flowering period,part of them started to enlarge after several hours of culture,which was their earlist marker of development into embryoids.Part of enlarged microspores,then formed multicellular masses and developed further into embryoids. The results of experiments on sucrose concentration with the spring Brassica napus showed that the number of microspores,survived after 3 days culture in the medium added with 16% sucrose were the largest,as high as 16.13%. But the embryoid induction frequency after 30 days culture was highest in the medium with 13% sucrose up to 144 embryoids for one flower bud.When the microspores were cultured in the medium with 16% sucrose for 3 days,and then added an equal volume of medium with 13% sucrose,the embryoid induction frequency was enhanced greatly,up to 3.7 times of that cultured all time in the medium with 13% sugar.The experiment system developed by us for rape,is being used for induction and screening of sclerotinia sclerotiorum resistant mutant and introduction of foreign gene into rape.