Molecular Biolgy/Physiology

 

Newton, I P; Cowling, R M; Lewis, O A M.
Growth of calcicole and calcifuge Agulhas Plain Proteaceae on contrasting soil types, under glasshouse conditions.
South African Journal of Botany, v.57, n.6, 1991:319-324
Abstract: Seven species of Proteaceae, Protea compacta, P. obtusifolia,
Leucadendron xanthoconus, L. meridianum, Leucospermum cordifolium, L.
truncatum and two populations of Aulax umbellata, from the Agulhas Plain,
south-western Cape, were grown in acid sand and neutral limestone sand in pots
in a greenhouse. Heights were measured monthly, and after 400 days the plants
were harvested and the dry weights of shoots and roots determined. Species
normally growing on acid sands showed signs of chlorosis and necrosis when
grown on limestone soils, and weights at harvesting were significantly less
than for the same species grown on acid sand. Species normally growing on
limestone soils were not significantly different in height or weight when
grown on either soil type. Mean species root weight in all but one case was
more for plants grown on acid sands than on limestone soils. It is suggested
that soil type plays the major role in the failure of calcifuge species to
establish themselves on limestone soils, but that competition is probably more
important in the reverse case. Some suggestions for future research into the
physiological tolerances of conspecifics under controlled conditions and field
conditions are made.

Plouvier, V.
Study on the occurrence of flavonic heterosides in some Dicotyledons: Distribution and taxonomic significance of diosmin,
linarin, hesperidin and luteolin.

Bulletin du Museum National d'Histoire Naturelle Section B Adansonia Botanique Phytochimie, v.13, n.1-2, 1991:109-120
Abstract: Eight flavonoid glycosides have been isolated from 35 plants
distributed in a variety of families: diosmin from 15 species (3 Salicaceae, 2
Umbelliferae, 6 Campanulaceae...), linarin from 8 species (3 Thymelaeaceae, 3
Polemoniaceae...), hesperidin (2 Calycanthaceae), luteoloside (2
Campanulaceae...), hyperin (Ferulago), rutin (Prunus, Purshia, Meliosma),
swertiajaponin (Scabiosa), swertisin (Dipsacus). Distribution and taxonomic
data on the first four glycosides. Eximin has been isolated from Protea
compacta.

Le Maitre, D C; Midgley, J J.
Allometric relationships between leaf and inflorescence mass in the genus Protea [Proteaceae]: An analysis of the exceptions to the rule.
Functional Ecology, v.5, n.4, 1991:476-484
Abstract: Recent studies have demonstrated that the sizes of plant parts are
allometrically related. In this study we investigated the relationship between
leaf and inflorescence mass in 35 species and one interspecific hybrid in the
morphologically and developmentally plastic genus Protea (Proteaceae). We show
that the basic relationship is biomechanically based and identify four ways in
which species have escaped this constraint: firstly, species with terminal
inflorescences which delay the flowering of their inflorescence for a year
after initiation have a high ratio of inflorescence to leaf mass; secondly,
species with pendulous terminal inflorescences which have a similarly high
ratio; and thirdly, species which have axillary inflorescences and thus escape
the biomechanical constraint of supporting the mass of an inflorescence at the
end of a branch. Fourthly, species with a prostrate habit have a low ratio of
leaf to inflorescence mass, whether or not they belong to groups with terminal
or axillary inflorescences. The allometric approach provides an objective
method for identifying exceptions and how they may have arisen, and for
formulating testable hypotheses about the adaptive value of traits.

Rourke, J P.
A new species of Protea (Proteaceae) from Namaqualand [South Africa] with comments on the Kamiesberg as a center of endemism.
South African Journal of Botany, v.56, n.2, 1990:261-265
Abstract: Protea namaquana Rourke, a new species endemic to the Kamiesberg in
Namaqualand, is described. Its distribution area is disjunct from that of the
related P. sulphurea Phill. from which it differs in having an upright growth
habit, longer, narrowly oblanceolate to linear-spathulate leave and crimson
coloured involucral bracts. Attention is drawn to the Kamiesberg as an
outlying area of fynbos and a centre of edemism in the Namaqualand region.


Hoot, Sara B.; Douglas, Andrew W.. Phylogeny of the Proteaceae
based on atpB and atpB-rbcL intergenic spacer region sequences.
Australian
Systematic Botany, v.11, n.3-4, Nov. 24, 1998.:301-320.
Abstract: Parsimony analyses were conducted for 46 genera representing all
subfamilies and tribes within Proteaceae using two chloroplast sequences: the
gene atpB and the noncoding spacer region between atpB and rbcL. The spacer
region was more variable than atpB and provided insertion and deletion data as
well as nucleotide substitutions. The atpB and spacer region data sets were
highly congruent (as indicated by the partition homogeneity test) and were
analysed separately and combined. Both unweighted and weighted character
states (3: 1 correction for transition bias) for the atpB data resulted in
very similar strict consensus trees. In addition, the large subfamilies
Proteoideae and Grevilleoideae were analysed separately, using appropriate
outgroups determined by the analyses with complete sampling. The results from
the combination of data were better resolved and supported than the results
from each separate data set, although the Grevilleoideae were highly
unresolved in all analyses. Most subfamilies in the Proteaceae were
essentially monophyletic, but most tribes and subtribes were not. Bellendena
is weakly supported as the sister group to all remaining members of the
Proteaceae. Monotypic Eidotheoideae is well supported as a member of
Proteoideae. Carnarvonioideae and Sphalmioideae are strongly supported as
closely allied to the Grevilleoideae, but their positions in relation to this
subfamily are unresolved. Other unusual alliances supported by our molecular
data are: Isopogon-Adenanthos-Leucadendron-Protea, Petrophile-Aulax,
Cardwellia-Euplassa-Gevuina, and Opisthiolepis-Buckinghamia-Grevillea. The
tree resulting from the combined data showed limited congruence with
morphological characters (flower pairs, stylar pollen presentation, and ovule
number). Congruence with chromosome number was minimal, but our tree does
support previous hypotheses of multiple aneuploidy and chromosome doubling
events. The African and South American genera included in our analysis are
dispersed among various clades with taxa from Australia and Asia, suggesting a
former Gondwanian distribution for Proteaceae.