Cucurbit Genetics Cooperative Report 3:63 (article 34) 1980
V. A. Parthasarathy and C. N. Sambandam
ICAR Research Complex for NEH Region, Shillong-793 003, India (first author); Faculty of Agriculture, Annamalai University TN-608 101, India (second author)
Detailed karyo-morphological studies of Cucumis callosus were made from root tip squashes following the procedure of Parthasarathy and Sampathkumar (1). Observations made on several metaphase plates revealed the presence of 24 chromosomes in the somatic cells. The length of 1.67 µ. The karyotype is symmetrical in view of the preponderance of median centromeres. The karyotype is presented in the following table.
Table 1. Length and arm ratio of the chromosomes of Cucumis callosus.
Length of chromosomes (µ) |
||||||
No. of chromosomes for each type |
long arm |
short arm |
total |
L/S ratio |
Relative length |
Position of centromere and secondary constriction |
| 4 | 1.00 | 1.00 | 2.00 | 1.00 | 19.95 | median and satellite |
| 6 | 1.00 | 1.00 | 2.00 | 1.00 | 29.93 | median |
| 2 | 1.00 | 0.75 | 1.75 | 1.33 | 8.73 | sub-median |
| 4 | 1.00 | 0.50 | 1.50 | 2.00 | 14.96 | sub-median |
| 2 | 0.75 | 0.75 | 1.50 | 1.00 | 7.48 | median |
| 2 | 1.25 | 0.25 | 1.50 | 5.00 | 7.48 | sub-median |
| 2 | 0.65 | 0.65 | 1.30 | 1.00 | 6.48 | median |
| 2 | 0.75 | 0.25 | 1.00 | 3.00 | 4.99 | sub-median |
| 24 | ||||||
Literature Cited
- Parthasarathy, V. A. and R. Sampathkumar. 1979. Karyo-morphological studies on Cucumis sp. cv. Vellari. Curr. Res. 8:175-176.