TITLE:
The Effects of Multilocus Heterozygosity on the Longevity of Seedlings Established on Fallen Logs in Picea jezoensis and Abies sachalinensis
AUTHORS:
Momoko Okada, Keiko Kitamura, Chunlan Lian, Susumu Goto
KEYWORDS:
Cox Proportional Hazards Model, Fallen Log, Inbreeding Depression, Microsatellite, Survival Census, Tree Regeneration
JOURNAL NAME:
Open Journal of Forestry,
Vol.5 No.4,
April
13,
2015
ABSTRACT: Seedling
establishment on fallen logs is a major regeneration system for tree species in
boreal forests. Seedling survival on fallen logs is affected not only by the
microsite environment but also by the genetic factors of individuals. To
quantify the genetic effects on seedling longevity, we identified seedlings
using a number tag system and collected needles of Picea jezoensis and Abies
sachalinensis established on fallen logs in spring 2006. Survival or death
of each seedling was investigated during 2006-2012. We genotyped seedlings with
microsatellite markers and calculated individual-based multilocus
heterozygosity (MLH) for each seedling. A Cox proportional hazards model was
applied to evaluate the effects of MLH on seedling longevity of the two species
considering the fallen log conditions. The model indicated that MLH positively
affected seedling longevity in P.
jezoensis, whereas the effects of MLH were not significant in A. sachalinensis. Here, we discuss
differences in the effects of MLH on seedling longevity between the two
species, considering species characteristics and MLH frequency distribution.