GRU Information Resource 1: Guide to how to cross peas.wmv
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
🌼 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.
🏷️ 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
💡Tweezers
💡Ethanol
💡Bud stage
💡Anthers
💡Style
💡Pistil
💡Stigma
💡Keel
💡Pollination
💡Labeling
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.
Transcripts
i'm going to demonstrate to you what you
need to do in order to cross peas
so the three pieces of equipment you
need
you need a sharp pair of tweezers
a small bottle of ethanol in which to
sterilize the tweezers in between going
between one plant and another
and some labels
so the first thing you need to do
is to select a flower at the right stage
so what we're looking for is a flower at
the bud stage before it's actually
opened by the time the flowers are fully
open like this these two
the flower is already pollinated and
that's no use
so in here we have earlier more immature
buds this one is at the bud stage and
should be a good candidate for crossing
so
what you do
is go in with tweezers and carefully
remove the petals
starting with the outer petals and then
going in and removing the keel
this clearly exposes the anthers and the
style
the heart of the flower
carefully take off the anthis
remove them all
there is the style ready to receive the
pollen
so that style is all ready to receive
pollen you don't have to wait
at all so
i'm going to come in with a flower from
another line here coloured flower line
which is more developed it will still
have
viable pollen in it and i'm going to
just
manually
hold back the petals
pull back the keel and that'll reveal
the stigma
with the pollen
on the end we can use this
as a paintbrush
to apply the pollen from this flower
onto the recipient
style
it's nice and visible you can see the
yellow pollen
so that is now ready
to be labelled up
so i'm going to go through the process
again
so
first of all you select your female
recipient flower
and you're looking for
a flower that's at the bud stage
here's a good one here
so you hold the flower in its correct
position and you
strip off
the petals going from the base of the
flower going either side of the keel
pulling the outer petals off first
and there's the keel with all the
anthers and the style inside you just go
in at the base of the keel
to thin
going at the base
you're
likely just to
go in without taking any of the other
structures out
taking a few of the answers there you
are you see the
remaining anthers and the stigmatic
surface in the
flower still there so
take off the remaining
and this
there you are
as the stigmatic surface ready to
receive pollen
so here's a
flower that is just about to open so
this flower is uh
the anthers will have dehisce inside so
it's no use to use as a female flower if
you go in pull back the outer
standard and wings
hold those in one hand
then firmly pull the keel from the base
pull it back
to expose
the style
which is full of pollen acts as a paint
brush
use that
to apply
the pollen large amount of pollen there
one flower because the male flower will
be enough to do several pollinations if
you get it at this stage
so the flower there is ready for tagging
i'm using these jewelers tags
the body is quite delicate so you want
to be able to sort of hold it and lasso
it carefully
and draw the string
around the base of that flower
clearly only one flower so that flower
has been crossed no need to bag it
it's not going to be visited you're not
going to get fallen
pulling on it now
the information of the cross is put onto
the label
and that's it
crossed pea flower
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