THESIS

accessions, hence, considered to have rare values (Cababasay, 1996). In the boxplots,
they are generally highlighted with in an asterisk (*) and/or zero (0) which are found
beyond the tails of outer fences (Gardiner, 1997).
From the sample of the PROC UNIVARIATE (species outlier) output for
germination period descriptor (Figure 1), the boxplot indicates that 12 accession
(13.5 %); TS02906, TS02245, TS03049, TS03052, TS03053, TS02728, TS02813,
TS02862, TS02877, TS02937, TS02940 and TS02955 were the possible outlier. This
was because they have asterisk and zero mark outside the fence which means they
have extreme values not normally exhibited by the 77 accessions. The identified
outliers (Table 6) show wide range of variation since these outliers were taken from
six countries in Southeast Asia. For instance, the TS02813 and TS02877 accessions of
Laos were a Solanum torvum. Accessions regarded as an outlier in 6 traits. Of the
same species, TS02728 accession from Thailand and TS02955 accession from
Cambodia had extreme values for germination period, plant height, plant breadth,
number of flowers per inflorescence and number of fruit per infructescence. This
indicated that the species had been taken from different parts of Southeast Asia.
However, plant breadth was the higest among the population for outlier
(20.2 %) and follows by fruit length (18.0 %). This indicated that both characters have
higher variation than other characters. In contrast the characters of 100 seeds weight
(1.1 %) and Fruit stalk length (1.1 %) were small in the oulier populations.This result
shows that both characters have less variation among 89 accessions belonging to
Solanum spp. and both characters should be considered in the cluster analysis.
In addition, if they were dropped, the 89 accessions used will be reduced to 33
accessions, which is 37.08 % of total number of accessions considered. Hence, the
outliers identified from the given set of accessions were suspected to their own group
isolated from normal non-outliers. Except the accessions of S. melongena were
eliminate from normal non-outliers. Therefore, the 69 accessions were considered in
the cluster analysis.
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