首页 | 本学科首页   官方微博 | 高级检索  
     


Reconstruction of reproductive diversity in Hypericum perforatum L. opens novel strategies to manage apomixis
Authors:Fritz Matzk ,Armin Meister,Renata Brutovská  , Ingo Schubert
Affiliation:Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstrasse 3, D-06466 Gatersleben, Germany. matzk@ipk-gatersleben.de
Abstract:The mode of reproduction was characterized for 113 accessions of the tetraploid facultative apomictic species Hypericum perforatum using bulked or single mature seeds in the flow cytometric seed screen (FCSS). This screen discriminates several processes of sexual or asexual reproduction based on DNA contents of embryo and endosperm nuclei. Seed formation in H. perforatum proved to be highly polymorphic. Eleven different routes of reproduction were determined. For the first time, individual seeds were identified that originated from two embryo sacs: the endosperm from an aposporous and the embryo from the legitimate meiotic embryo sac. Moreover, diploid plants were discovered, which apparently reproduce by a hitherto unknown route of seed formation, that is chromosome doubling within aposporous initial cells followed by double fertilization. Although most plants were tetraploid and facultative sexual/apomictic, diploid obligate sexuals and tetraploid obligate apomicts could be selected. Additionally, genotypes were detected which at a high frequency produced embryos either from reduced parthenogenetic or unreduced fertilized egg cells. The endosperm developed most frequently after fertilization of the central cell in aposporous embryo sacs (pseudogamy) but in few cases also autonomously. The genetic control of apomixis appears to be complex in H. perforatum. Basic material was developed for breeding H. perforatum, and strategies are suggested for elucidation of inheritance as well as evolution of apomixis and for molecular approaches of apomixis engineering.
Keywords:apomixis    embryo    endosperm    flow cytometric seed screen    Hypericum perforatum    reproductive pathways
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号