GRU Information Resource 1: Guide to how to cross peas.wmv

Summary

This instructional script outlines the process of pea plant cross-pollination. Key equipment includes tweezers, ethanol for sterilization, and labels. The focus is on selecting flowers at the bud stage, carefully removing petals and anthers to expose the stigmatic surface. A flower from another line serves as the pollen donor, with its pollen applied to the recipient flower's style. The script emphasizes the importance of correct flower selection and the meticulous technique required for successful cross-pollination, concluding with labeling the crossed flower for identification.

Takeaways

• 🔍 To cross peas, you need a sharp pair of tweezers, a small bottle of ethanol for sterilization, and labels for marking.
• 🌼 Select a flower at the bud stage, before it fully opens, as fully opened flowers are already pollinated and not suitable for crossing.
• ✂️ Use tweezers to carefully remove the petals and the keel, exposing the anthers and the style, which is the reproductive part ready to receive pollen.
• 🚫 Do not use flowers that are already open, as they are no longer viable for the crossing process.
• 🌱 The style, once exposed, is ready to be pollinated and does not require waiting.
• 🎨 Use a flower from another line with viable pollen as a 'paintbrush' to transfer pollen onto the exposed style of the recipient flower.
• 🏷️ After successful pollination, label the crossed flower to record the cross information, which is crucial for tracking the genetic lineage.
• 👁️‍🗨️ Ensure that the flower used for pollen is at a stage where the anthers have dehisced and the pollen is viable.
• 💡 When removing the keel, be careful not to damage the stigmatic surface, which is essential for successful pollination.
• 📝 Accurate labeling is key to tracking the crosses and is important for future reference and research.

Q & A

What are the three pieces of equipment needed for crossing peas?

A sharp pair of tweezers, a small bottle of ethanol for sterilization, and some labels are the three pieces of equipment needed.

Why is ethanol used in the process of crossing peas?

Ethanol is used to sterilize the tweezers in between working with different plants to prevent contamination.

What stage of the flower should be selected for crossing peas?

A flower at the bud stage, before it has fully opened, should be selected for crossing peas.

Why should the flower not be fully open for the crossing process?

A fully open flower is already pollinated and therefore not suitable for controlled crossing.

How does one remove the petals from the pea flower for crossing?

The petals are removed carefully using tweezers, starting with the outer petals and then removing the keel to expose the anthers and style.

What is the purpose of removing the anthers from the flower?

Removing the anthers ensures that the flower's own pollen does not interfere with the cross-pollination process.

What is the role of the style in the crossing process?

The style is the part of the flower that receives the pollen during the crossing process.

How is pollen transferred from the donor flower to the recipient flower?

Pollen is transferred by using the stigma of a donor flower as a 'paintbrush' to apply pollen onto the style of the recipient flower.

Why is it important to label the crossed pea flowers?

Labeling is important to keep track of the cross information, ensuring that the offspring can be correctly identified and studied.

What type of tag is recommended for labeling the crossed pea flowers?

Jeweler's tags are recommended due to their delicate nature, which allows for careful handling and labeling of the flowers.

Why is bagging not necessary after crossing the pea flowers?

Bagging is not necessary because the goal of crossing is to control pollination, and once the pollen has been applied, no further pollination is required.