杜鹃园艺品种‘王妃’与黄杯杜鹃远缘杂交亲和性研究
Study on the Compatibility of Distant Hybridization between Rhododendron Horticultural Varieties of ‘Empress’ and R. wardii

为了更好利用杜鹃野生资源开展远缘杂交育种，本试验以杜鹃园艺品种‘王妃’和野生黄杯杜鹃为研究对象，通过测定花粉活力，采取不同授粉方法克服种间杂交受精前障碍，并通过花粉管生长荧光观察确定其杂交不亲和的细胞学特性。结果表明：MTT染色法与离体培养法检测花粉活力差异较大，黄杯杜鹃花粉经加热培养后，活力显著降低；但加热授粉方式坐果率仍然较高。在4种授粉方式中，常规授粉方式最适合，坐果率最高。将种胚进行无菌培养后，其种子不萌发，‘王妃’与黄杯杜鹃杂交后不亲和。通过荧光观察，远缘杂交组合在授粉后2 d开始出现大量胼胝质，最终仅少量花粉管进入胚珠，该组合存在一定的受精前障碍。
In order to better utilize the wild resources of Rhododendron and carry out distant hybrid breeding, this experiment took the horticultural variety Rhododendron ‘Empress’ and the wild Rhododendron of R. wardii as the research objects, and overcame the prezygotic barrier of interspecific hybrid by different pollination methods, and determined the cytological mechanism of hybrid incompatibility by fluorescence observation. The results showed that there was a conspicuous difference in pollen viability between MTT staining method and pollen germination in vitro method, and the viability of R. wardii pollen was significantly reduced after heated culture; however, the fruiting rate of the heated pollination method was still higher. Among the four pollination methods, the conventional pollination method was the most suitable and had the highest fruit set rate. After the seed embryo was aseptically cultured, its seeds did not germinate, and its hybrid incompatibility between Rhododendron ‘Empress’ and R. wardii. By fluorescence observation, the distant hybrid combination began to show a large amount of callus 2d after pollination, and eventually only a small amount of pollen tubes entered the ovule, and there was a certain pre-fertilisation barrier in this combination.