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

Matzk, F Meister, A Brutovska, R Schubert, I

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

17

INGLESE

Article

Plant Sciences","Animal & Plant Sciences

PLANT JOURNAL

0960-7412 → ACNP

26

3

2001

275 - 282

ISI

0960-7412(200105)26:3<275:RORDIH>2.0.ZU;2-1

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.