Passion fruit is very popular in Taiwan owing to its good taste and being suitable to be fresh food or processing food. Passion fruit cultivation area is up to 682 hectares in Taiwan. “Tainung No. 1” (Fig.1) is a good passion fruit variety with high quality and high yield and does not need to be artificial pollinated that could reduce labor cost. The cultivation area of “Tainung No. 1” is more than 80% of total passion fruit cultivation area in Taiwan. The major production regions in Taiwan are Pingtung (in spring) and Nanto (in summer and autumn) so that passion fruit can be produced in whole year. The main problem of passion fruit cultivation and production are unhealthy seedlings and virus infection in field. The Animal and Plant Health Inspection Agency (APHIA) has established and implemented a healthy seedling system for passion fruit. In response to the need of passion fruit seedling producers, Taiwan Seed Improvement and Propagation Station (TSIPS) has successfully developed the mass production technology of passion fruit “Tainung No. 1” tissue culture seedlings and virus detection by molecular biological techniques (PCR or RT-PCR) was included. The tissue culture technology for mass production passion fruit plantlets can be used to preserve and propagate virus-free plantlets and to be applied in mother stock and scion nursery to eliminate the risks of the maintenance for traditional mother stock orchards.

TSIPS indicated that, in order to keep the variety characters, grafted seedlings are used universally for passion fruit seedling production. There are six virus recorded on passion fruit in Taiwan. Those includes: 1. Cucumber mosaic virus (CMV), 2. East Asian Passiflora virus (EAPV-AO type and EAPV-IB type), 3. Euphorbia leaf curl virus (EuLCV), 4. Papaya leaf curl Guangdong virus (PalCuGDV), 5. Telosma mosaic virus (TeMV) and 6. Passion fruit crinkle virus (PCV). However, passion fruit is perennial crops and susceptible to viral diseases which affect plant growth and fruit quality. Healthy and virus-free seedlings are important for passion fruit production and the old ones in orchard should be replaced with virus-free seedlings for controlling viral diseases. For farmers’ urgent demand for healthy seedlings, TSIPS developed tissue culture system (Fig.2) with specific-virus-free molecular detection process which will stabilize the mass propagation of virus-free tissue culture plantlets for the mother stock.

As passion fruit is loved by domestic consumers, in order to cultivation needs of farmers, TSIPS prepares passion fruit tissue culture propagation technology (Fig.3) and commissions Taiwan Agricultural Research Institute to verify virus-free seedlings by molecular biological inspection. In the future, the tissue culture virus-free seedlings and technologies for passion fruit can be provided for the seedling industry, and growers and seedling producers are welcome to consult. (04-25825431, or E-mail: cluwen@tss.gov.tw).

▲Figure 1. Fruit of “Tainung No. 1” passion fruit

▲Figure.2. Tissue culture system for rooting in Tainung No. 1 passion fruit plantlet.

▲​​​​​​​Figure 3. Mass propagation of specific-virus-free in Tainung No. 1 passion fruit plantlet by tissue culture.