23种常绿杜鹃亚属植物种间杂交的可育性研究

Cross fertility of intra-subgen. Hymenanthes of 23 Rhododendron species

该文对常绿杜鹃亚属(subgen. Hymenanthes)的12个亚组23种杜鹃花的64个杂交组合进行了研究,包括云锦杜鹃亚组(subsect. Fortunea)、银叶杜鹃亚组(subsect. Argyrophylla)及同亚属的其他10个亚组[杯毛杜鹃亚组(subsect. Falconera)、弯果杜鹃亚组(subsec. Campylocarpa)、麻花杜鹃亚组(subsect. Maculifera)、粘毛杜鹃亚组(subsect. Glischra)、露珠杜鹃亚组(subsect. Irrorata)、大理杜鹃亚组(subsect. Taliensia)、树形杜鹃亚组(subsect. Arborea)、蜜腺杜鹃亚组(subsect. Thomsonia)、星毛杜鹃亚组(subsect. Parishia)、火红杜鹃亚组(subsect. Neriiflora)]。结果表明:(1)常绿杜鹃亚属内的异种杂交具有很高的可育性,在64个杂交组合中可育与高可育组合56个(占87.5%),无弱可育等级。(2)不亲和与败育组合8个,不能坐果(Cab)、不能结实(Sab)和结实不发芽(Sng)之比为3∶1∶4,并与杂交双亲的亲缘有一定关联,初步推断同时存在前合子期不亲和(pre-zygotic incompatibility)与后合子期败育(post-zygotic abortion)的情形。(3)与相应的自然授粉比较,常绿杜鹃亚属内杂交会不同程度地导致可育性降低,但有15个组内与组间杂交组合表现了某种"超亲和"现象,尽管不能完全排除人工杂交对于结实与可育性的加强作用。(4)常绿杜鹃亚属内不同种类间杂交,存在双向可育与单向不育(unilateral sterility)现象,但未见双向不育情况。

We studied the special cross of intra-subgen.Hymenanthes,64 hybridized combinations between 23 species of twelve subsections of Rhododendron subgen.Hymenanthes.Twelve subsections were subsect.Fortunea,subsect.Argyrophylla and the other ten subsectiones(subsect.Falconera,subsect.Campylocarpa,subsect.Maculifera,subsect.Glischra,subsect.Irrorata,subsect.Taliensia,subsect.Arborea,subsect.Thomsonia,subsect.Parishia,subsect.Neriiflora).The results were as follows:(1)In the specific cross of intra-subgen.Hymenanthes the hybrid showed a good and high fertility,combined fertile accounted for 87.5%,and no weak fertility.(2)There were eight hybridized combinations for incompatibility and sterility occurred before or after fruit stage and capsul aborted(Cab),seed aborted(Sab)and seed not germinated(Sng)showed 3∶1∶4,which had the relationship with both parents and may have pre-zygotic incompatibility and post-zygotic abortion.(3)Compared with the corresponding natural pollination,hybridization of some fertile indicators usually appeared a declining to different degrees,but there was“super affinity”phenomenon from fifteen hybridized combinations in the part of intra-or inter-subsections although that not completely eliminated the artificial hybridization to strengthen the phenomenon for seeding and fertility.(4)There were phenomena of bilateral fertility and unilateral sterility but bilateral sterility in different kinds of inter-specific hybridizations of subgen.Hymenanthes.