sodininkystė ir daržininkystė 25(4)

y than constant periods of cold. Although more complicated than the whole-plant
method, this technique is best suited for the evaluation of freeze-thaw cycling as it
is non-destructive and allows for continual sampling of the same tissues over
multiple freeze-thaw cycles.
Screening seedlings of Malus, 16–20 weeks after emergence, using a protocol
to induce acclimation and select the hardiest individuals could improve the efficacy
of breeding for cold hardiness by eliminating a large proportion of cold-tender seedlings
before time and maintenance costs are invested in field plantings. Plant viability,
collected in the form of binomial values and used to calculate percent seedling survival
was a simple, efficient and precise method to segregate seedling populations for
cold hardiness. We are presently running field trials with these same genotypes in the
hopes of getting a test winter to compare our controlled studies to in vivo field
results.
Acknowledgements. Thanks to K. McRae and B. Walker for their statistical
help and A. LeBlanc and M. Cao for their technical assistance.
Gauta 2006-11-09
Parengta spausdinti 2006-12-11
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