Feulgen-cytophotometrical measurement of nuclear DNA content in 27 strains of Ae. squarrosa revealed intraspecific variation, which was continuous, the highest value being 1.23 times greater than the lowest. Mean DNA values in an increasing order were var. typica (435.5), var. meyeri (446.6), var. anathera (464.7) and var. strangulata (468.6) and an intermediate type between typica and anathera was between the two in mean DNA value, also.
Intravarietal differences were significant in all varieties measured except var. stragulata. Variation in nuclear DNA content of Ae. squarrosa may be caused by lengthwise duplications or deficiencies of small segments of almost all chromosomes.