Germination and emergence of understorey and tall canopy forbs used in naturalistic sowing mixes. A comparison of performance in vitro v the field

摘要

This study investigated the chilling requirements for germination and emergence of imbibed seed of understorey and tall canopy forbs used in naturalistic sowing mixes, in vitro and the field. Many of these species have some form of endogenous dormancyand chilling increased germination in all species except for Polemonium reptans. Of the 18 species tested, 12 species showed greatest germination after 60 and 90 days chilling. Highest germination under in vitro conditions was obtained in Dodecatheon meadia (96.67%) and Primula vulgaris (81.67%). Many understorey species germinated in the fridge at 4°C when chilled for longer than 60 days. Sixty days chilling was the best compromise between breaking dormancy and preventing germination in the fridge. Mean species emergence in the field was significantly different (p<0.01) to that in vitro for most species. Species that germinated well in vitro also emerged well in the field however the degree of correspondence varied widely. The study suggests that simple, standardised tests that better predict field emergence of dormant species are required to improve the reliability of seed mixes containing these species.