杜鹃花属植物种质创新研究进展

杜鹃花是中国传统十大名花之一,栽培历史悠久,具有较高的观赏价值。相对于中国丰富的野生杜鹃花资源,国内杜鹃花种质创新进展缓慢。目前杂交育种仍是杜鹃花属植物种质创新的主要技术手段。杂交亲本的选择、正反杂交(向性)、杂交亲本的亲缘关系及系统分类地位等都会影响杂交的亲和性,因杂交亲和性的差异,受精障碍可能发生在受精前、后的各个不同阶段。针对受精前、后障碍,可以通过不同的授粉方法、杂交组合的合理配置,结合胚拯救技术,克服受精障碍,提高杜鹃花属植物的育种效率。虽有杜鹃花多倍体育种的相关研究报道,但人工诱导的多倍体商业品种还比较少见。秋水仙素(Colchicine)、氨磺灵(Oryzalin)、氟乐灵(Trifluralin)等在杜鹃花多倍体诱导中都有应用,杜鹃花多倍体在观赏特性上表现出叶片肥厚、花大等性状,一般对逆境胁迫的生长适应性也会提高,但也有杜鹃花多倍体抗性减弱的报道。多倍体可以帮助恢复杂交亲本育性,作为杂交亲本进行远缘杂交,有利于提高远缘杂交亲和性,采用异源多倍体可以克服因远缘杂交带来的缺少成对染色体配对而导致的杂种不育等问题。杜鹃花的转基因工程中,主要以农杆菌介导法和基因枪法为主,其中农杆菌介导法的基因转化率较高。本综述结合国内外的研究报道,对相关研究概况方面展开全面论述,以期为后期的杜鹃种质创新研究提供理论依据和技术支撑。

Researches Advances in Germplasm Innovation of Rhododendrons

Rhododendron is one of the top ten traditional flowers in China.It has a long history of cultivation and high ornamental values.Compared with the abundant resources of wild rhododendrons in China,the progress of Rhododendron germplasm innovation is still slow.At present,the traditional cross breed is still the main technical means of Rhododendron breeding.The selection of cross parents,reciprocal crosses(the direction feature),genetic relationship and taxonomic status of cross parents all affect the compatibility of hybridization.Due to the difference of cross compatibility,fertilization obstacles may occur at different stages before and after fertilization.In view of the obstacles before and after fertilization,the breeding efficiency of Rhododendron can be effectively improved by different pollination methods,rational allocation of cross combinations and embryo rescue techniques.Although there have been reports on Rhododendron polyploid breeding,artificially induced polyploid commercial varieties are still rare.Colchicine,oryzalin and trifluralin were used in the polyploid induction of rhododendrons.The polyploid of Rhododen drons has the ornamental characteristics of plump leaves and large flowers.Generally,its adaptability to adversity stress will be improved,but there are also reports that showed the resistance became weakened.Polyploidy can restore the fertility of hybrid parents.It can improve the compatibility of distant hybridization when used as a hybrid parent.Furthermore,the use of heteropolyploidy can overcome the problem of hybrid sterility caused by lack of pairing chromosomes in distant hybridization.In the transgenic engineering of Rhododendrons,the Agrobacterium mediated method and the gene gun method were used,and the agrobacterium mediated method had higher gene conversion rate.Based on the reports at home and abroad,the related research on Rhododendron germplasm innovation was discussed in details in this paper in order to provide theoretical basis and technical support for the later research of Rhododendron germplasm innovation.