During 1987, we selected the six fastest-growing seedlings or clones from each of 15 provenances that represented the natural distribution range of silver maple (Acer saccharinum L.). Shoots from all 90 trees were cut into nodal segments, rooted as cuttings, and maintained as clonal stock plants in the greenhouse. Rooting was generally excellent and more than half of the clones rooted ≥90%. At the same time, explants were obtained from these field-grown trees and many were established in vitro as aseptic cultures by first pretreating with benomyl and rifampicin. Single-node explants from the greenhouse-grown clonal stock plants were also established and multiplied in vitro. There was a significant effect of clone within provenance on all in vitro growth characteristics. All clones proliferated axillary shoots, but not all at the same rates. Although statistically significant, low correlation coefficients indicated that micropropagation results were not good predictors of nursery performance of the populations from which the clones were selected, nor of the climatic conditions at the site of origin of the trees. The micropropagation system reported herein, therefore, should be applicable to a wide variety of silver maple genotypes. Chemical name used: methyl [1-[butylamino)carbonyl]-1H-benzimidazol-2-yl]carbamate(benomyl).
Cortisol directly impacts Flavobacterium columnare in vitro growth characteristics
