Large disparity in recombination fractions reported in Picea mariana for the Aat-1 / Pgi-2 linkage group

• Published in: Canadian Journal of Botany
• Main Authors: Ringius, Gordon S., Innes, David J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1990
• Subjects: Plant Science; Canada; Newfoundland
• Online Access: http://dx.doi.org/10.1139/b90-070; http://www.nrcresearchpress.com/doi/pdf/10.1139/b90-070

A survey of 84 trees in a natural population of Picea mariana located near St. John's, Newfoundland, yielded 3 trees heterozygous for the Aat-1/Pgi-2 linked locus pair. Segregation analysis of this linkage group in 330 megagametophytes resulted in an estimated pooled recombination fraction of 0.015. This is the lowest known recombination fraction for this linkage group in the Pinaceae. It is in contrast with earlier reports of recombination fractions of 0.155 and 0.250 from other populations of P. mariana in eastern Canada. The presence of substantial variation in recombination fractions in populations from eastern Canada precludes a regional selection–adaptation explanation. The cause of this variation is unknown. Substantial variation, both temporal and spatial, in other linkage groups suggests that the basis of linkage variation is complex and in need of further investigation in the Pinaceae.