Cytogenetics of tropical bulbous ornamentals III. Mitotic mosaicism in 3x Crinum augustum

Abstract

Triploid Crinum augustum contains two types of complements (2 n = 33, 32 + Te) in the meristems of primary and secondary roots, together with a small amount of aneusomaty. This condition is maintained by efficient vegetative reproduction. The normal complement (2 n = 33) contains 11 triplets. The 32 + Te complement tallies with the former except that one of the small submedian chromosomes of the XIth triplet is replaced by a telocentric which more or less tallies in size with the short arm of the missing chromosome. The telocentric probably arose through misdivision early in ontogeny in which the complete centromere was in the smaller arm. The longer acentric arm, lost in a few subsequent cell generations, is not expected to exercise any deleterious effect because of the polyploid nature of the taxon. Only cells containing the full complement of 33 chromosomes are selected in the male germ line.

Cytogenetics of Amaryllidaceae. VI. Karyomorphology and meiotic behaviour of Crinum zeylanicum L. - A new cytotype.

“…The presence of 2n=22 chromosomes in RTCs and n=11 chromosomes in PMCs of C. zeylanicum confirms earlier reports on its diploid number (Sharma andBhattachrya 1956 andKhoshoo 1971). In the lack of aneusomaty the present report is in disagreement with Sharma and Bhattacharya (l. c.) but agrees with Raina and Khoshoo (l.c.).…”

Karyotype Analysis with Differential Banding in Crinum pratense and Crinum defixum.

“…3,12) as reported by the previous workers (Raina andKhoshoo 1971, Alam et al 1991). Karyotype formulae prepared from orcein stained materials were 11 m+11 sm and 10 m+ 12 sm for C. pratense and C. defixum, respectively (Table 1).…”

Genetic mechanisms underlying evolution in Crinum.

“…The latter could be resolved in 11 groups of 6 chromosomes each. The eleven groups conform to the usual size pattern (Raina and Khoshoo 1971a).…”

“…In the next 45.5% cells instead of the regular complement of 33 chromosomes, there are found 32 plus a small telocentric chromosome. The telocentric chromosome corresponds to the short arm of the third small submedian chromosome of the last triplet (Raina and Khoshoo 1971b). Four deviant cells (2.5%) were found to have 33+Te, 37+Te, 34 and 32 complement of chromosomes.…”