The effect of seed stratification on germination of 14 Cupressus species

For 14 Cupressus species growing outside their natural range (C. arizonica, C. cashmeriana , C. duclouxiana, C. dupreziana, C. funebris, C. glabra, C. goveniana, C. guadalupensis, C. lusitanica, C. macnabiana, C. macrocarpa, C. numidica, C. pygmaea and C. torulosa) germination was compared between thirty day chilled and unchilled seed. Chilling and species effects were highly significant for all germination parameters considered. Chilling x species interaction was observed for germination value (GV) and mean germination time (MGT). The germination capacity of filled seed (GCF) after one month was increased by chilling pretreatment from 43% to 73%. Chilling increased germination in all species (except for C. guadalupensis), but it significatively enhanced germination capacity and speed in: C. cashmeriana, C. duclouxiana, C. glabra and C. macrocarpa. Chilling also increased uniformity in C. glabra, C. cashmeriana and C. funebris, while a high intraspecific variability remained in C. arizonica, C. guadalupensis, C. lusitanica, C. numidica and C. torulosa for both treatments. After chilling germination capacity remained low for C. macnabiana, C. dupreziana, C. guadalupensis, C. numidica and C. torulosa, but C. macnabiana and C. dupreziana had failed to germinate without chilling.