作 者 ：Gu De-Xing, Hsu Ping-Sheng
期 刊 ：植物分类学报 1991年 5期
Keywords:Variation Pattern, Population, Nanjiang,
Abstract:
Pinellia ternata (Thunb.)Breit. (Araceae)is a perennial herb widely distributed in
East Asia. It is common in the suburbs of Nanjing. Recently, another species of the same ge-
nus has been found in a Nanjing suburb. It resembles P. ternata in general appearance, but
never possesses terrestrial bulbils which are characteristic of that species. Morphologically, it
is more similar to P. yaoluopingensis X. M. Guo et X. L. Liu, a new species recently found in
Anhui, than to P. ternata.
The present paper deals with a comparative study of the variation pattern of two
entities at the population level in order to elucidate their biological relationships. The follow-
ing research work was carried out: (1)field investigation of the population sites; (2)mass
sampling of natural populations for quantitative analysis, two populations (Population I &
II) for P. ternata and one (Population III) for P.yaoluopingensis, aff.; (3) SEM observation
of pollen grains; (4)examination of somatic chromosome numbers.
As a result of the above observations, it was found that:
I. Measurements of the quantitative morphological characters (Table 1 & 2) show that
Population III differs remarkably from Populations I & II, but matches the original descrip-
tion of P.yaoluopingensis except for its lacking of small tubers. SEM micrographs of pollen
grains (Plate 1 )show that Populations I & II are very similar to each other, but different from
Population III both in morphology and in size. The overall morphological relationships
among these three populations are shown in Fig. 2.
II. The habitats of Populations I & II, though rather different in moisture and light con-
ditions, are similar with respect to human disturbance, and quite different from that of Popu-
lation III. Pinellia ternata shows some weedy characteristics. It occurs in hedgegrows and
shady man-made groves. The vigorous vegetative reproduction by terrestrial bulbils pro-
ducing clones of P.ternata has evidently anabled the plant become successfully adapted to its
varied environments.
III. Cytological investigation shows that both somatic chromosome numbers of
Populations I & II (P.ternata) are 2n = 72 (Plate 2-1 & 2), inconsistent with all previous
records (2n=28, 115, 116, 128). It appears to be an aneupolyploid. The chromosome
number of Population III (P.yaoluopingensis, aff.)is 2n=26 (Plate 2-3). It is probably a
diploid.
Two problems deserve further study: (a) Is Population III identical with Pinellia ya-
oloupingensis or a new variation form of that species? (b) Has P. ternata originated
from the outbreeding P. yaoloupingensis?