Echinochloa colona (L.) Link of Malaya and Java, and Indian strains of cultivated species,
E. frumentacea (Roxb.) Link, were certained to be hexaploid, n=27, and to have the same genome constitution in common.
Although the F
1 hybrids of these two species showed a low degree of fertility, it can be assumed that
E. colona is a wild form of
E. frumentacea.
In earlier paper the author (Yabuno 1953) has confirmed that hexaploid varieties of
E. crus-
galli (L.) Beauv. and Japanese cultivated strains have the same genome constitution, and that the former is a wild form of the latter.
Four F
1 hybrids between Indian strains of
E. frumentacea and hexaploid varieties of
E. crus-
galli, and an F
1 hybrid between Indian strain of
E. frumentacea and Chinese cultivated strain were cytologically investigated. It is concluded that
E. colona and
E. crus-
galli do not possess genomic constitution in common. The same conclusion can be adopted to Indian and Chino-Japanese cultivated strains. But any genomic formula was not assigned to these species in this paper.
Indian and Chino-Japanese cultivated strains have been maintained under the specific name,
E. frumentacea. On the basis of the results of cytological investigations Chino-Japanese cultivated species was separated from
E. frumentacea, and the new specific name,
E. utilis Ohwi et Yabuno was given.
E. colony and
E. crus-
galli can be distinguished in some morphological characters, particularly with respect to panicles character, and these two wild species differ more or less in geographic distribution.
E. utilis and
E. frumentacea resemble to
E. crus-
galli and
E. colona respectively in the characteristics of panicle. From the evidences mentioned above, it is assumed that
E. utilis has arisen from the hexaploid varieties of
E. crus-
galli probably in the Far East, and
E. frumentacea from
E. colona in the tropics.
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