3333

Summary

The transcript discusses the implementation of bioassay projects related to Full Armyworm and Brown Plant Hopper, focusing on two options for testing BT proteins. Thailand is highlighted as a key player with its established lab and population of Full Armyworm. However, sourcing specific BT proteins poses a challenge in Southeast Asia. The discussion also touches on the complexities of conducting bioassays, requiring multiple generations and careful testing. The session emphasizes collaboration and planning, with upcoming meetings planned to address specific protocols and regional challenges. A focus is placed on sharing experiences and ensuring participants are well-prepared for implementation.

Takeaways

• 😀 The testing of BT proteins should be carefully managed to avoid confusion over which toxin is effective in case of success, requiring single protein compounds for clarity.
• 😀 Option 2 testing requires experienced individuals with established colonies, knowledge of protocols, and access to pure protein compounds, which may be difficult to source internationally.
• 😀 Thailand is in a strong position for testing and has established a colony and protocols, but sourcing specific proteins (like Cry1) remains a challenge.
• 😀 International regulations have recently changed, making it impossible for certain groups to ship pure BT proteins for research purposes, creating a barrier to sourcing materials.
• 😀 Countries considering Option 2 should carefully evaluate their readiness, and Thailand, having established protocols, is encouraged to continue with their work in this direction.
• 😀 For Option 2 bioassays, maintaining a large population of full armyworms (50 males and 50 females) for multiple generations is essential for homogenizing the genome before testing.
• 😀 Only neonate stages of full armyworms should be tested with BT, as they are the first to consume the leaves and are most exposed to the toxin.
• 😀 Testing BT concentration requires precise calibration, with multiple increments to determine the lethal concentration needed for complete mortality, followed by replications for statistical accuracy.
• 😀 A separate meeting will be held to focus on Option 1 and Option 2, with an emphasis on specific protocols, materials, and challenges faced by participating countries.
• 😀 Countries unsure about whether to pursue Option 1 or Option 2 are encouraged to consult with more experienced nations, such as Thailand and Indonesia, for guidance and expertise in bioassay protocols.
• 😀 Future meetings will focus on action plans for participating countries, with discussions on shared experiences, data collection, and collaboration opportunities, especially regarding pheromone testing and field trials.

Q & A

What is the main challenge when choosing Option 2 for BT testing?

The main challenge when choosing Option 2 is ensuring that you have the necessary resources, including time, expertise, and access to pure BT toxin proteins. You need to be able to establish and maintain a large, homogenized population of full army worms and accurately test the concentrations of BT toxins.

Why is it problematic to test a product with a mixture of different BT proteins?

Testing a product with a mixture of BT proteins can be problematic because if the product fails, it's unclear which specific protein caused the failure. If the product works, it’s also unclear which protein is effective, making it difficult to determine the concentration of each toxin being tested.

What is required to conduct Option 2 for bioassays successfully?

To conduct Option 2 for bioassays successfully, you need an established colony of full army worms that have been maintained for several generations, experience with BT testing, access to pure single protein compounds, and the ability to conduct bioassays with correct concentration ranges.

What is the significance of maintaining a colony of full army worms for Option 2?

Maintaining a colony of full army worms is critical for Option 2 because it allows you to homogenize the population's genetic makeup over multiple generations, ensuring consistency in your testing. It’s important to begin with a relatively small number of individuals (e.g., 50 males and 50 females) and let the population grow before testing.

What life stage of the full army worm should be tested for BT toxicity, and why?

The life stage that should be tested for BT toxicity is the neonate stage. This is because neonates are the ones exposed to the BT toxins in the leaves and are more likely to provide accurate results for how the toxin works at that early stage.

What are the challenges involved in determining the correct concentration of BT for testing?

The challenges in determining the correct concentration of BT include finding the right dose that kills 100% of the individuals while also identifying the minimal concentration required for effective results. Achieving this requires creating several concentration increments and conducting multiple replications to establish accurate dose-response curves.

What did Thailand face in terms of sourcing specific BT proteins?

Thailand faced a significant challenge in sourcing specific BT proteins, particularly Cry proteins, due to a lack of suppliers in the region. Despite having access to technical-grade BT with high purity, obtaining the specific proteins needed for research proved difficult.

Why is it recommended that Thailand continue with their current approach despite these challenges?

Thailand is encouraged to continue with their current approach because they already have a well-established colony of full army worms and the expertise needed for Option 2. Their success in overcoming previous obstacles with BT testing suggests they are in a good position to proceed.

How long does it typically take to develop a reliable bioassay protocol for full army worms?

Developing a reliable bioassay protocol for full army worms typically takes several months. This is due to the time required to refine the rearing process, perfect the artificial diet, and ensure consistent results through multiple developmental stages and bioassay trials.

What should countries with fewer resources consider when choosing between Option 1 and Option 2?

Countries with fewer resources should carefully consider whether they have the necessary expertise, equipment, and facilities for Option 2. If they do not, it may be more practical to choose Option 1, which is a simpler and less resource-intensive approach.