Early seed development in the annual and perennial Secale taxa

Abstract

The early embryo and endosperm development patterns of five annual taxa and three perennial taxa of the genus Secale were analyzed. The results showed that there was considerable variation in the speed of early embryo and endosperm development within the genus Secale, and that the developmental patterns of the annual and perennial taxa overlapped. Comparisons indicated that DNA content per se did not have any influence on the speed of early embryo development or aberrant endosperm nucleus production in either the annual or perennial taxa. However, comparisons between the percent telomeric heterochromatin and the number of embryo cells produced showed a significant positive correlation in the annual taxa, and a nonsignificant correlation in the perennial taxa. There was a positive correlation between the number of aberrant endosperm nuclei and percent telomeric heterochromatin in the annual taxa, while the perennial taxa showed a nonsignificant but negative correlation. The results suggest that percent telomeric heterochromatin has a different effect on early seed development in the annual taxa than in the perennial taxa.Key words: Secale, heterochromatin, DNA content, embryo cell cycle.