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RING‐POSITION AND FREQUENCY OF ADJACENT DISTRIBUTION OF MEIOTIC CHROMOSOMES IN RHOEO SPATHACEA
Author(s) -
Lin Yue Jee,
Paddock Elton F.
Publication year - 1973
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1973.tb05974.x
Subject(s) - centromere , biology , meiosis , chromosome , chiasma , distribution (mathematics) , ring chromosome , genetics , karyotype , mathematics , gene , mathematical analysis
The morphological sequence of the twelve chromosomes around the ring as worked out by Sax is reaffirmed with slight corrections of the centromere position on three chromosomes: Aa, fA, and Dd. Adjacent distribution was found in 53/120 MI PMC (44.2%). Ring‐position analysis was achieved in 34 of the 53. There were 127 chromosomes and 66 arm‐pairs involved in adjacent distribution in these 34 MI PMC. Adjacent distributions occurred at random among the twelve chromosome positions and among the twelve arm‐pair positions. There were eleven instances among the 66 arm‐pairs (16.7%) of adjacent distribution despite free ends due to chiasma failure. Up to four consecutive chromosomes may pass to the same pole. Not all cells with 6–6 distribution are genetically balanced. Distribution of 7–5 occurred in 24/120 AI PMC (20.0%). Another nine (7.5%) in the same sample had one or more lagging chromosomes. At MI, three PMC had 8–4 distribution, but none such were seen at AI.