Karyotypic Polymorphism in Paris hexaphylla Cham., with Special Reference to Its Origin and to the Meiotic Chromosome Behavior
1937 Volume FujiiJubilaei Issue 2 Pages 681-700
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1937 Volume FujiiJubilaei Issue 2 Pages 681-700
1) Six karyotypes were distinguished in Paris hexaphylla CHAM. which has a basic chromosome number 5 consisting of morphologically distinguishable chromosomes A, B, C, D and E. Four of them were diploid and two triploid:
Diploids (2n=10) Triploids (2n=15)
Karyotype 1 C C D D Karyotype 1 C C C D D D
Karyotype 2 C C- D D Karyotype 2 C C C- D D- D-
Karyotype 3 C C D D-
Karyotype 4 C C- D D+
Karyotypic aberration concerns only chromosomes C and D. C-- and D+-chromosome were suggested as having resulted from simple translocation from C short arm to trabant of D. D--chromosome was interpreted as originated from a simple deletion of the whole trabant of D. Except the homozygous diploid C C D D and the triploid C C C D D D all other karyotypes were heterozygous as to C- or D-type chromosome or both of them.
2) There was no distributional or ecological difference between diploids and triploids and between the karyotypes, showing that polyploidy and the karyotypic changes found in this plant are not suf iiciently effectual to cause a biological differentiation.
3) The heteromorphic constitutions of D-D- bivalents and D-D--D- trivalents were easily discerned at meiosis in PMCs. Heteromorphic short arm segregates equationally as well as reductionaily at first anaphase. The ratio of reductional to equational segregation was 1.0:5.3 in C C D-D diploid.
4) Metaphase-anaphase behavior of the trivalents was discussed an the basis of observations an anaphase segregation of 5 trivalents metaphases. Anaphase behavior of the trivalent is a regular one for itself, segregating 1 to 2 chromosomes. Thus from 5 trivalents metaphases only the gametes with 5-10 chromosomes comprising at least a complete haploid set must result. This was really verified in the present study.
It is the writer's pleasure to express his sincere thanks to Professor H. MATSUURA under whose valuable suggestions and encouragement the present work was carried out.
