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

JIC Germplasm

5 Jul 201205:57

Summary

TLDRThis 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.

Outlines

00:00

🌼 Cross Pollination of Peas

This paragraph demonstrates the process of cross-pollinating peas. The narrator explains the necessary equipment: sharp tweezers, ethanol for sterilization, and labels for marking. The ideal flower for cross-pollination is identified as one at the bud stage, not yet fully open. The steps include carefully removing the petals and keel to expose the anthers and style, which are the reproductive parts of the flower. The anthers are then removed, leaving the style ready to receive pollen. A flower from another line with viable pollen is used to pollinate the first flower by using the stigma of the second flower as a 'paintbrush' to transfer pollen to the style of the first. The process is concluded with labeling the crossed pea flower.

05:02

🏷️ Tagging Crossed Pea Flowers

In this paragraph, the focus is on the final steps of the cross-pollination process, specifically tagging the crossed pea flowers. The narrator uses jewelers' tags to mark the flower, emphasizing the delicacy of the task due to the flower's fragile nature. The tag is carefully lassoed around the base of the flower to avoid damage. The narrator clarifies that only one flower is tagged per cross, eliminating the need for bagging to prevent pollination by other sources. The cross information is then recorded on the label, completing the process of cross-pollinating pea flowers.

Mindmap

Keywords

💡Crossing

Crossing refers to the process of transferring pollen from one plant to the stigma of another plant of a different variety or species for the purpose of producing offspring with a new combination of traits. In the video, crossing is the main technique demonstrated, specifically for peas, where the goal is to hybridize different pea plants to create new genetic combinations.

💡Tweezers

Tweezers are a type of precision tool used for grasping small objects. In the context of the video, a sharp pair of tweezers is essential for carefully removing the petals and anthers from the flower without causing damage, which is critical for the successful pollination during the crossing process.

💡Ethanol

Ethanol is an alcohol-based substance commonly used as a disinfectant. In the video, a small bottle of ethanol is used to sterilize the tweezers, ensuring that no contaminants are transferred between plants, which could affect the success of the crossing or introduce diseases.

💡Bud stage

The bud stage is a developmental phase in a flower's life cycle before it fully opens. In the video, selecting flowers at the bud stage is crucial for crossing because it indicates that the flower is not yet pollinated and is ready to receive pollen for successful hybridization.

💡Anthers

Anthers are the part of a flower that produces and holds pollen. In the script, the removal of anthers from the female flower is a key step in the crossing process to ensure that no self-pollination occurs, allowing for the introduction of pollen from a different plant.

💡Style

The style is the part of the pistil that connects the ovary to the stigma in a flower. In the video, the style is exposed after removing the anthers and is prepared to receive pollen from another flower during the crossing process.

💡Pistil

The pistil is the female reproductive part of a flower, consisting of the stigma, style, and ovary. The script describes the careful handling of the pistil during crossing, as it is the part that will receive the pollen and potentially lead to fertilization and seed production.

💡Stigma

The stigma is the receptive surface on the pistil where pollen lands and germinates. In the video, the stigma is exposed after removing the anthers and is ready to receive pollen from a male flower to facilitate the crossing process.

💡Keel

The keel is a protective structure in some flowers that houses the anthers and style. In the script, the keel is removed to access the anthers and style, which is necessary for the crossing process to occur.

💡Pollination

Pollination is the transfer of pollen from the male part (anther) to the female part (stigma) of a flower, enabling fertilization and the production of seeds. The video demonstrates manual pollination as part of the crossing process to control the genetic outcome of the peas.

💡Labeling

Labeling in this context refers to the practice of marking flowers or plants to identify specific crosses or treatments. The video mentions the use of labels to record the details of the cross, which is important for tracking the genetic lineage and outcomes of the hybridization process.

Highlights

The necessity of three pieces of equipment: tweezers, ethanol, and labels.

Selecting a flower at the bud stage for successful crossing.

Avoiding flowers that are fully open as they are already pollinated.

Removing petals with tweezers to expose the flower's anthers and style.

The importance of sterilizing tweezers with ethanol between plants.

Carefully removing all anthers to prepare the style for pollen.

Choosing a more developed flower with viable pollen for pollination.

Manual manipulation of petals and keel to reveal the stigma.

Using the stigma as a 'paintbrush' to apply pollen to the recipient style.

The visibility of yellow pollen indicating successful transfer.

Labeling the crossed flower for tracking and record-keeping.

Stripping off petals from the base to expose the keel and style.

Taking care not to damage other flower structures during the process.

The readiness of the stigmatic surface to receive pollen after anther removal.

Selecting a flower just about to open for optimal pollen transfer.

Pulling back the outer standard and wings to expose the style full of pollen.

The sufficiency of pollen from one male flower for multiple pollinations.

Tagging the crossed flower with a delicate method to avoid damage.

Recording the cross information on a label for future reference.