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18<br />
(Table 5) indicating that selection for fruit size<br />
might reduce TSS or TA. Therefore, improving of<br />
fruit size and TAA or TA may be carried out in<br />
separate crossing plan and combining these traits<br />
later. However, the correlations between all fruit<br />
traits associated with fruit size with TSS and TA<br />
were quite low (-0.26 ≤ r ≤ -0.38), thus probably<br />
not of much practical importance. Three chemical<br />
fruit traits; TSS, TA, and AA were weakly<br />
positively correlated (0.20 ≤ r ≤ 0.27) among<br />
themselves, while these three traits were negatively<br />
correlated with pH. Most of physical traits,<br />
especially FW had no correlation with AA.<br />
One objective of this guava-breeding program<br />
is to develop new cultivars with larger fruit and<br />
high ascorbic acid. These results indicated that<br />
selection for large fruit with high ascorbic acid<br />
was feasible.<br />
CONCLUSION<br />
Repeatability estimates for FW, FLT,<br />
FLW, SCW, TA, pH, and AA were relatively high,<br />
indicating that response to selection for these traits<br />
would be realized in breeding program. Generally,<br />
three fruits per genotype provided sufficient<br />
efficiency for evaluating guava fruit traits. Most<br />
chemical traits had weak positive or negative<br />
correlation with fruit size, suggesting that early<br />
screening for chemical traits could be assayed<br />
indirectly using FW.<br />
ACKNOWLEDGEMENTS<br />
This research was financially supported<br />
by The Kasetsart University Research and<br />
Development Institute, a grant from The Graduate<br />
School of Kasetsart University, and the Thailand<br />
Research Fund.<br />
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