Reconstruction of reproductive diversity in Hypericum perforatum L. opens novel strategies to manage apomixis

Citation
F. Matzk et al., Reconstruction of reproductive diversity in Hypericum perforatum L. opens novel strategies to manage apomixis, PLANT J, 26(3), 2001, pp. 275-282
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT JOURNAL
ISSN journal
0960-7412 → ACNP
Volume
26
Issue
3
Year of publication
2001
Pages
275 - 282
Database
ISI
SICI code
0960-7412(200105)26:3<275:RORDIH>2.0.ZU;2-1
Abstract
The mode of reproduction was characterized for 113 accessions of the tetrap loid facultative apomictic species Hypericum perforatum using bulked or sin gle mature seeds in the flow cytometric seed screen (FCSS). This screen dis criminates several processes of sexual or asexual reproduction based on DNA contents of embryo and endosperm nuclei. Seed formation in H. perforatum p roved to be highly polymorphic. Eleven different routes of reproduction wer e determined. For the first time, individual seeds were identified that ori ginated from two embryo sacs: the endosperm from an aposporous and the embr yo from the legitimate meiotic embryo sec. Moreover, diploid plants were di scovered, which apparently reproduce by a hitherto unknown route of seed fo rmation, that is chromosome doubling within aposporous initial cells follow ed by double fertilization. Although most plants were tetraploid and facult ative sexual/apomictic, diploid obligate sexuals and tetraploid obligate ap omicts could be selected. Additionally, genotypes were detected which at a high frequency produced embryos either from reduced parthenogenetic or unre duced fertilized egg cells. The endosperm developed most frequently after f ertilization 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 engi neering.