利用荧光原位杂交技术分析新合成异源四倍体拟南芥

在植物异源倍化育种中或者通过异源多倍化导入有利基因时，初级杂交后代异源多倍体减数分裂期间，避免部分同源染色体干扰，使同源染色体正常联会和配对以及正确分离是产生功能性雌雄配子的细胞学基础。本研究通过种间杂交技术，获得初级杂交后代异源四倍体拟南芥A. suecica，并重点分析其花粉母细胞减数分裂期同源染色体联会和配对情况。利用DAPI技术染色证明了花粉母细胞减数分裂期间核内染色体数目的正确性和均等分裂；而用荧光原位杂交技术进一步证明了核内染色体组的来源的正确性和同源染色体联会和配对的精准性。该结果证实新合成异源多倍体能进行正常的减数分裂和产生功能性雌雄配子，为种属间杂交和异源多倍体育种以及植物杂种优势利用提供了有利的细胞遗传学证据。

FISH Analysis of Resynthesized Allotetraploid Arabidopsis

Allopolyploidy breeding or introduction of preferential gene(s) via allopolyploidization is widely attempted in production of new crops. Thus at the onset of establishment of new allopolyploids, the functional gametes are reproduced conditioning that normal events such as synapsis and pairing and correct segregation of homologous chromosomes are guaranteed with the avoidance of possible interference of homoeologous chromosomes during meiosis. In the present study, we reported on meiotic synapsis and pairing of homologous chromosomes during the development of pollen mother cells in the newly resynthesized allotetraploid Arabidopsis aided with DAPI staining and FISH technique. The results showed that the correct number of nuclear chromosomes and balanced segregation were frequently observed with DAPI staining, and FISH analysis further provided the improved resolution of synapsis and pairing of homologous chromosomes, and the investigated nuclear chromosomes derived from different parental lines had no interference with each other, and the synapsis and pairing of homologous chromosomes were clearly identified. Therefore, the results indicated that the newly resynthesized allotetraploid Arabidopsis may achieve the normal meiosis and propagate the functionalized gametes for fertilization, confirming a potential vigor of intra/interspecific hybridization and a cytological basis for allopolyploid breeding.