genotypes. It is clear that environment contributed to
the small portion of variations in fresh tuber yield and
inulin content (4–5%), whereas genotype contributed
a larger portion to the variations (54–56%). A large
estimate of genetic variance indicates that selection
and breeding initiatives can proceed immediately
(Ordon˜ez et al. 2005). The contribution of genotype
9 environment interaction was higher than that
of environment but it was still lower than the
contribution of genotypic differences in fresh tuber
yield and inulin content (Table 3).
In contrast to this study, the environment contributed
to a large portion of variations in tuber fresh
weight, whereas genotype and genotype 9 location
contributed a smaller portion to variations (Pimsaen
et al. 2010). The environment, accession and genotype
9 environment interaction were highly signifi-
cant for tuber yield per plant (Berenji and Sikora
2001; Baldini et al. 2004). The results both supported
and contrasted to those in previous studies possibly
largely due to materials used and the differences in
environments.
The variations in biomass as affected by environment
and genotype 9 environment differences were
significant but smaller than the variation of genotype.
However, days to maturity and HI were mainly
affected by the variations caused by season.
Figure 2 showed patterns of genotype 9 environment
interactions of high and low groups of Jerusalem
artichoke accessions for inulin content. The high
and low groups were separated to reduce confounding
effect in genotypes with intermediate performance.
The interactions within high or low groups were high,
whereas the interactions between groups were rather
low. Therefore, high and low groups were clearly
separated except for few accessions, but identification
of Jerusalem artichoke accessions for high or low
inulin content within high or low groups was difficult.
Previous study in 37 cultivars of Jerusalem artichoke
could identify the genotypes with high fructose
content (Grando, Kharkov, C-122, Meillo and Dubo)
(Ben Chekroun et al. 1996). However, there accessions
were not included in this study. Inulin contents
in different maturity classes were also studied in