Meiotic behaviour in two natural intergeneric hybrids among New Zealand everlastings (Asteraceae, Gnaphalieae)

作者：McKenzie R J^*; Lovis J D; Ward J M

来源：New Zealand Journal of Botany, 2015, 53(2): 117-123.

DOI：10.1080/0028825X.2015.1011673

• Leucogenes grandiceps
• Ewartiothamnus sinclairii
• Anaphalioides bellidioides
• New Zealand flora
• Raoulia eximia
• meiosis
• intergeneric hybridisation

Rare wild hybrids occur between five of the six genera in the New Zealand endemic Raoulia alliance. Some of these intergeneric hybrids are partially male and female fertile despite the remarkable phenotypic divergence of the parental species. In this preliminary study, meiotic behaviour was investigated in microsporocytes of two wild hybrids, Anaphalioides bellidioides x Ewartiothamnus sinclairii and Leucogenes grandiceps x Raoulia eximia, to obtain insights into the cytological phenomena responsible for the reduced pollen fertility of the hybrids. In the A. bellidioides x E. sinclairii hybrid, up to five chromosomal bodies were non-aligned along the metaphase plate in metaphase I, and laggard chromosomes and chromosomal bridges were observed in anaphase I. Micronuclei were observed in telophases I and II in 20% and 24% of microsporocytes, respectively. These abnormalities were observed at a low frequency in the L. grandiceps x R. eximia hybrid, which showed more highly regular meiosis. The difference in meiotic regularity shown by the two hybrids is in stark contrast to the comparative phenotypic divergence of the parental species.

• 出版日期2015-4-3