## 3 Results  
Changes in Respiration Rate, Ethylene Production, Peel and Pulp Color during Mango Fruit Development and Ripening  
In this study, three cultivars of mango fruits were collected at different maturity stages. The respiration rate was unsteady in the early developmental stage and suddenly reached a peak at the full ripening. The increase in respiration rate was more rapid in 'Kaituk' than  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**cDNA** & **TaqMan MGB Probes** & **Primer Sequences** \\ \hline _MiPSY_ & ACAGGCAACGACAGAGAG & F: CATGGGAATTGCACCTGAT \\  & R: GCCAAGGCACAGCATTGTGAGACA \\ \hline _MiPDS_ & TGCTATTGGACTTTCTC & F: TTGGCCCGACAAGTCAAGT \\  & R: GATTGTCCACAAGCATTGCCT \\ \hline _MiZDS_ & TCCCTGGAATTAAAAAGAT & F: TGCATATGTGTGCATGATG \\  & R: CCCTCCACGACAATGGAAGT \\ \hline _MiCRTISO_ & CTATGCAAAGAAG & F: GGCAGGGAATGTCTCAAAAGG \\  & R: CCAATTATTCTCCTCCCAAGT \\ \hline _MiLCYb_ & TGATGCAACTGGGTTTT & F: ACAATTCAGGCCTGGTGTGTGT \\  & R: GCTTATCATACTAGAACAGGCACCTA \\ \hline _MiLCYc_ & TTTCTCCGTTACCCAA & F: GGCATCAGGCACATTTTCCCAT \\ \hline _MiHYb_ & CTCTCTCTCTGAAAATGTTCG & F: CAAATGAGGGTGTCAGGT \\  & R: CAGCACCCAACAGin the other two cultivars. Similar trends were also observed in ethylene production. The ethylene production was unstable at a low level in the early developmental stage before it immediately increased in the full ripening stage, and higher ethylene production was found in 'Kaituk' than in the other two cultivars (Figure 2).  
The differences in the peel and pulp color were determined by chroma and hue values, and color was expressed as the four values, including L* for the lightness (0-100), a* for green (\(-\)) to red (\(+\)), b* for blue (\(-\)) to yellow (\(+\)), and hue for yellow (90\({}^{\circ}\)) to green (180\({}^{\circ}\)). In mango peel, L* values continuously increased and then remained constant at the ripening stage from 74-98 days after full bloom in the three cultivars. The a* value continuously increased over fruit development and ripening in all cultivars. The b* values increased more rapidly in 'Kaituk' than other cultivars. In the meantime, the b* values continuously decreased and then slightly increased at the full ripening stage in 'Nam Dok Mai Sithong' and 'Nam Dok Mai No.4'. The hue values notably decreased during fruit development and ripening until close to 90\({}^{\circ}\) at the full ripening stage in the three cultivars (Figure 3).  
In mango pulp, the L* values were unchanged at the early fruit developmental stage before they dramatically dropped at the full ripening stage. The a* and b* values continuously increased over fruit development and ripening. The increase in b* value was more rapid in 'Kaituk' than the other two cultivars over fruit development and ripening. Contrastingly, the hue values greatly declined during fruit development until close to 90\({}^{\circ}\) at the full ripening stage in the three cultivars (Figure 4).  
Figure 3: L*, a*, b*, and hue values in peel of mango fruit cv. ’Nam Dok Mai Sithong’, ’Nam Dok Mai No. 4’ and ’Kaituk’ during fruit development (45–88 days) and full ripening stage (98 days). The vertical bars represent the means with SE for three replications.  
Figure 2: Changes in respiration rate and ethylene production of mango fruit cv. ’Nam Dok Mai Sithong’, ’Nam Dok Mai No. 4’ and ’Kaituk’ during fruit development (45–88 days) and full ripening stage (98 days). The vertical bars represent the means with SE for three replications.