Floating Chromosomal Populations in Saccharum spontaneum L
1974 年 39 巻 4 号 p. 681-696
詳細
1974 年 39 巻 4 号 p. 681-696
The present work deals with a study of cytological races in S. spontaneum L. from the plains of North-western India. Six cytotypes, C1, C2, C3, C4, C5, C6, have so far been identified with haploid chromosome numbers n=20, 21, 22, 27, 28 and 36 respectively. The cytotypes with n=21 and n=22 chromosomes are new reports.
Chromosome mosaicism, desynapsis, non-congression of a few bivalents at the equatorial plate, multipolar spindle formation, lagging of univalents, bivalents, and anaphasic bridges are amongst the meiotic abnormalities observed. Karyotypes are described in three cytotypes, namely, C4 with 2n=40, C6 with 2n=54 and C1 with 2n=72+4f. It is concluded that intraspecific variations are due to both numerical and structural chromosomal alterations.
