Polyploidy and radiosensitivity in wheat and barley

Chromosome weights and measures in the Triticinae

“…Measurements of chromosome length made during the present work (see tables 2 and 4) agree with those of Bhaskaran and Swaminathan (1960) in so far as the observed values in the hexaploid are significantly lower than the lengths of AABB + DD (P = <0.001). The shorter chromosome lengths observed in the hexaploid cannot, in the light of the results on chromosome volumes, be interpreted as reflecting a diminution of chromosome material.…”

“…As suggested earlier the compaction is probably the result of increased metaphase coiling and may well serve an adaptive function (Darlington, 1937). A shorter chromosome length in the polyploid wheats has been reported by others Bhaskaran and Swaminathan, 1960). It must be emphasised, however, that the shorter length does not, as has been claimed, reflect a diminution 2.…”

“…Using chromosome length as a measure of chromosome size, Bhaskaran and Swaminathan (1960) show significant variation between the chromosomes of the diploids, the tetraploids and the hexaploids. Pal and Swaminathan (1960) use this evidence together with information on DNA content obtained by Bhaskaran and Swaminathan (bc, cit.…”

Chromosomal Alterations in Mitotic and Meiotic System as Influenced by Gamma Rays <i>in Pisum</i>

“…The mode of action, quality and origin of these anomalies have been studied by a number of workers (Caldecott 1953, Caldecott and Smith 1952, and Bhaskaran and Swaminathan 1960. The type of induced aberrations depend upon whether the chromosomes are effectively monopartite or bipartite at the time of radiation (Caldecott and Smith 1952) .…”

Comparative karyokinetic response of diploid and autotetraplaid Trigonella foenum-graecum L. to gamma rays.

“…Conger and Johnston (1956) reported radiosensitivity in poly ploids and diploids to be same while Evans and Sparrow (1961) found radiosensitivity of polyploids to be lower than that of diploids. However, Mortimer (1958) and Swaminathan (1964) reported it to be higher while Bhaskaran and Swaminathan (1960) Fujii and Matsumura (1959) Swaminathan and Natranjan (1957) found radiosensitivity to be independent of level of ploidy. In these different reports both auto and allopolyploid material have been used and also different parameters have been taken.…”