The remote hybridization and polyploid breeding in genus Rhododendron, so called azaleas and rhododendrons

杜鹃花属由五个亚属组成。在4个亚属之间进行了不同的亚属间杂交; Hymenanthes，Rhododendron，Pentanthera和Tsutsutsi沿着，以及杜鹃亚属杜鹃组种间或远缘杂交，其中通过杂交组合获得了许多蒴果，即Hymenanthes Rhodendron（或相反）、Hymenanthes Pentanthera、Tsutsutsi Pentanthera和Rhodododendron Pentanthera。但膜瓣杜鹃和五蕊杜鹃的种子不能萌发，杂交组合，膜瓣杜鹃、五蕊杜鹃和筒杜鹃的种子甚至不能结蒴果。与预期的一样，杜鹃花属内种和/或品种间的杂交比亚属间的杂交更成功，尽管成功程度不如种间杂交。 ...更多信息 杜鹃花属在进化过程中因遗传分化而在膜花属、五花属或筒花属内形成了杂交。从杜鹃花和五花膜草中获得的后代有望产生优良的黄色品种，而从五花筒草中获得的后代几乎都不能形成叶绿素，因此需要更广泛的杂交。从杜鹃花属内杂交获得的后代也有望产生具有优良黄色或蓝色花朵的形式。在后一种情况下，粉红色形式的细胞质的引入显示出提供更旺盛的生长。尝试使用普通秋水仙素处理产生多倍体，但由于鹿儿岛的夏天太热，处理过的植物无法存活，所以失败了。因此，研究了可以诱导多个芽再生的组织培养。在培养基中加入细胞分裂素后，多重煤烟产生被证明是可行的。初步试验中，用0.05%秋水仙胺处理3 ~ 5d，可获得似多倍体的植株。少

Genus Rhododendron consists of five subgenera. Various intersubgeneric hybridizations were conducted among four subgenera ; Hymenanthes, Rhododendron, Pentanthera and Tsutsutsi along with interspecific or remote hybridizations between species and/or cultivars belonging to section Rhododendron of subgenus Rhododendron.Of these various hybridizations following cross combinations were succeeded and many capsules were obtained, that is, Hymenanthes Rhododendron(or reverse), Hymenanthes Pentanthera, Tsutsutsi Pentanthera and Rhododendron Pentanthera. However, seeds of Rhododendron Hymenanthes and those of Rhododendron Pentanthera failed to germinate and cross combinations, Pentanthera Hymenanthes, Pentanthera Rhododendron and Tsutsutsi Rhododendron even failed to produce capsules. As being expected, hybridizations between species and/or cultivars belonging to Rhododendron were more successful than those between subgenera, although the degree of success was inferior as compared with interspe … More cific hybridizations within Hymenanthes, Pentanthera or Tsutsutsi because of genetic divergence attained in the process of evolution in Rhododendron. The offsprings obtained from Hymenanthes Rhododendron or Hymenanthes Pentanthera were expected to produce excellent yellow cultivars, whereas almost all of those from Tsutsutsi Pentanthera failed to form chlorophyll and thus more extensive hybridizations would be needed. The offsprings obtained from crosses within Rhododendron were also expected to produce forms with excellent yellow or blue flowers. In the latter case introduction of cytoplasm of pink forms was revealed to afford more vigorous growth.An attempt to produce polyploid was done using ordinary colchicine treatment, but it failed because summer of Kagoshima was too hot for survival of treated plants. Therefore, tissue culture was examined in which multiple shoot regeneration could induce. With the addition of cytokinins into media multiple soot production was revealed to be feasible. In the preliminary experiment, plantlets which seemed to be polyploid were obtained through 0.05% colcemid treatment for 3 to 5days. Less