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Three selected transgenic papaya lines 124-3, 132-2 and 142-3 across the T 1 and T 2 generations were preliminarily evaluated under Biological Containment Level 2 (BL2) greenhouse approved by the National Committee on Biosafety of the Philippines (NCBP) to determine the partial stability of expression of resistance to papaya ringspot virus (PRSV) and selected phenotypic traits. e PRSV reaction of the three transgenic lines using mechanical inoculation test and enzyme-linked immunosorbent assay was assessed. e qualitative and quantitative horticultural traits at owering and ripe fruit stages of the transgenic lines were also evaluated. Based from preliminary results, the percentages of resistant progenies to PRSV in the T 1 generation were 83% for 124-3, 74% for 132-2, and 70% for 142-3. However, in the same generation, no di erence between the transgenic and non-transgenic were observed for stem, leaf and petiole color, fruit shape, peel, esh and seed color, stem diameter, number of days to rst ower, and fruit edible portion, indicating that the transgenic is seemingly stable. e percentage of resistant progenies to PRSV in the T 1 generation decreased in the T 2 generation, indicating that the inherited resistance of the three transgenic lines was unstable, and a continuous evaluation of the transgene could be done in later generations. In contrast, the light green (RHS 141B) stem color, dark green (RHS 141A) leaves and petioles and creamy white owers (RHS 155A) were stably expressed in both the T 1 and T 2 generations. e plant height for lines 124-3 and 142-3, internode length for line 142-3 and number of nodes to rst ower for lines 132-2 and 142-3 were also stable in both T 1 and T 2 generations. In addition, the pyriform fruit shape for hermaphrodite sex form and rounded fruit shape for the female sex form, light yellow orange (RHS 17A) peel color, bright yellow orange (RHS 23A) esh color and black (RHS 202A) seeds of the three transgenic lines were stably expressed in both generations. e fruit weight, total soluble solids and fruit edible portion for lines 124-3 and 142-3 was stably expressed in both generations.

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