New Zealand Journal of Botany abstracts
B00004Received 4 February 2000; accepted 7 July 2000
Genotypic variation of seedlings of wild populations of Cordyline
australis (Lomandraceae) in New Zealand
WARWICK HARRIS
Landcare Research
P.O. Box 69
Lincoln, New Zealand
Present address: Lincoln Botanical, 27A Edward St, Lincoln, New Zealand.
ROSS E. BEEVER
Landcare Research
Private Bag 92170
Auckland, New Zealand
Abstract Observations were made on seedlings grown under
uniform conditions of 28 wild populations of
Cordyline australis
(cabbage tree, ti kouka) from a wide latitudinal range in New Zealand and
single populations each of
C. banksii and
C. indivisa. There were
highly significant differences in leaf size and shape and in seedling colour
between the populations of
C. australis. Seedling leaves of
C.
banksii resembled in shape those of the four
C. australis
populations north of Auckland and one in north-west Nelson, suggestive of
possible introgression.
C. indivisa seedlings differed markedly in leaf
size and shape from the other species. The main trend in the genotypic
variation of
C. australis was clinal along a north-to-south latitudinal
gradient with seedling leaves becoming longer, narrower, and having a higher
frequency of red-brown coloration the further south the origin of the
population. There were populations that deviated significantly from this
latitudinal trend, and their locations suggest geographical foci of variation
of
C. australis independent of latitude, the distinction of which may
have been blurred by disturbances associated with human activity. The adaptive
function of the characters measured and how they may function in maintaining
the patterns of genotypic variation of
C. australis are discussed.
Keywords Lomandraceae; Cordyline australis; C.
banksii; C. indivisa; cabbage tree; genotypic variation; seedling
characters; leaf colour; latitudinal variation; New Zealand biogeography
New Zealand Journal of Botany, 2000, Vol. 38: 609-627
0028-825X/00/3804-0609 $7.00 (c) The Royal Society of New Zealand 2000
PDF file of entire paper: medium quality (891K); (scanned from paper original: notes about this process)
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