Chromosomal Studies of the Indian Coleopterans (Indian Beetles)
1973 年 38 巻 2 号 p. 363-373
詳細
1973 年 38 巻 2 号 p. 363-373
1. Cytological determination and sex chromosome mechanism of some seven species of Coleoptera belonging to four families have been made.
2. The general plan of meiotic division is uniformly similar in most of the studied species, first division being reductional and second division being equational for all the chromosomes.
3. The sex chromosomes show heteropycnotic behaviour during different stages of meiosis. Sometimes they take peculiar shape and size.
4. In first division, the bivalents are mostly rod-like.
5. The sex chromosomes show different types of configurations viz. Xy, Xyp, Xyr, and XO.
6. The chromosome number in most cases tallies with the type number i.e. 2n=9AA+XY.
7. In some cases chromosomal polyploidy and polymorphism have been encounter-ed.
8. The probable mechanism of evolution in the number of chromosomes has been discussed in the light of chromosomal structural changes.
