<p style="text-align: justify;"><b>Growth Habit and Ability to Overwinter</b></p>

<p style="text-align: justify;">Leaf, stem, and fruit morphologies of X17-2 plants were normal throughout the year. X17-2 plants continuously grow throughout the year; more vigorously when ambient temperatures are above 65F and more slowly during cool weather (i.e., temperatures 50-65F). Once warm temperatures commence in the spring X17-2 papayas resume vigorous growth whereas PRSV-infected non-transgenic papaya only slowly resume growth; not growing vigorously until high temperatures in mid-summer.</p>

<p style="text-align: justify;"><b>Life-Span and Vegetative Vigor</b></p>

<p style="text-align: justify;">Papaya plants may live up to 20 years, however, typically, viral infection, other diseases, or natural disasters reduce their life-span to 4-5 years; commercial plants are replaced after 2-3 years. The fifth generation of the X17-2 has been grown for over two years with some losses due to 4 hurricanes in 2005.</p>

<p style="text-align: justify;"><b>Days to Flowering and Fruit Maturity</b></p>

<p style="text-align: justify;">The days from planting to first flowering and the rate of fruit development is influenced by genetics, environmental conditions (mostly temperature), and cultural practices. During the summer, there were no observed differences in the days to flowering or rate of fruit maturity between X17-2 papayas and PRSV-tolerant papaya cultivars (e.g., &lsquo;Red Lady&rsquo;). During spring, fall, and winter, fruit development was slower for non-transgenic plants compared to X17-2 papayas, most likely due to the effect of the PRSV on leaf area and health.</p>

<p style="text-align: justify;"><b>Seed Parameters</b></p>

<p style="text-align: justify;">No differences among X17-2 line papayas and non-transgenic papayas in seed production, dormancy, percent germination, seedling survival, or seedling emergence.</p>

<p style="text-align: justify;"><b>Pollination and Reproduction</b></p>

<p style="text-align: justify;">After X17-2 seedling field establishment and once plants begin to flower (usually 4-5 months post planting), female plants are generally eliminated from the field since only hermaphrodites have the ability to self-pollinate (thus reducing the need for male plants) and possess the desired fruit characteristics. The X17-2 line papayas are self-compatible as are all hermaphroditic papaya plants, and there were no observed changes in flower morphology or potential pollinator species in the field plots. There were no observed differences in the fertility of the X17-2 line papayas compared to other commercial papaya cultivars. Papaya seeds do not shatter even if the fruit is damaged.</p>

<p style="text-align: justify;"><b>Weediness</b></p>

<p style="text-align: justify;">No Carica species is considered a weed, and there is no evidence in the scientific literature to suggest that susceptibility to PRSV is the factor that prevents these plants from being weed pests. Therefore, it seems likely that even if the PRSV-resistance trait could be transferred from line X17-2 to another Carica species, the resultant offspring would not be weed pests.</p>

<p style="text-align: justify;"><b>Secondary and Non-Target Adverse Effects</b></p>

<p style="text-align: justify;">It was concluded that the genes inserted into the transgenic papaya line X17-2 would not result in any deleterious effects or significant impacts on non-target organisms, including threatened and endangered species or beneficial organisms. The PRSV coat protein expressed in these papaya lines is found in all PRSV-infected plants, and there are no reports of this protein having any toxic effects. In fact, this viral coat protein is routinely ingested by virtually all animals, including humans, when papaya is consumed. Naturally occurring infections of susceptible papaya varieties result in concentrations of coat proteins far higher than those that occur in the tissues of the transgenic papaya line X17-2. No direct pathogenic properties, nor any hypothetical mechanisms for pathogenesis toward beneficial organisms, such as bees and earthworms, were identified for papaya line X17-2.</p>
