and Chaganti, 1973). At least three highly polymorphic 
species assemblages are recognized, namely C. aquatica 
Roxb., €. Lachryma-Jobi L., and C. gigantea Iwoen. 
C. aquatica and C. Lachryma-Joli have chromosome 
numbers of 2n=10 and 20 respectively, while in the case 
of C. gigantea populations with chromosome numbers 
of 2n=20 and 40 have been reported (Venkateswarlu 
and Chaganti, 1978). 
Comparative chromosome morphology, especially at 
the pachytene stage of meiosis, where the chromosomes 
are more extended than at mitotic metaphase and often 
present characteristic features, is a useful parameter in 
understanding interspecific and intergeneric  relation- 
ships. In the case of Coix, such studies have been few 
(Venkateswarlu and Chaganti, 1973). We have studied 
and report here the pachytene chromosome morphology 
in populations of Coix representing the three species. 
Materials and Methods 
Samples of seeds from populations representing the 
three species were assembled from different regions of 
India. Some were collected in the field by the authors, 
while others were collected for them by colleagues in 
different parts of the country. In addition, two samples 
from Japan and one trom Brazil (countries in which Coix 
is not native, but into which it has been introduced for 
use as a fodder, cereal or ornamental) were also obtained. 
The geographic origin and method of collection of all the 
seed material is listed in Table |. Plants were raised from 
these seeds in the experimental gardens of the Depart- 
ment of Botany of the Andhra University. Young in- 
florescences were fixed in 8:1 ethanol-acetic acid. After 
24-48 hours of fixation, the fixative was replaced by 70% 
ethanol. The material was stored in this fluid at 4° C, 
until used for study. 
r 
[ 206 | 
