3/23/09

Breeding Equipment



Equipment used in plant breeding is relatively inexpensive. See if you can find some of the items listed in the picture… Leave a comment if you have any other equipment that you find useful!

Magnifying glass (10 or 15 power) use to identify flower parts as early as possible. I use this all the time when determining sex of flowers, identifying pests, looking at flower parts in detail, just being curious etc. Every plant grower should have a magnifying lens. I have a 16 X magnifying lens. If you do not have a magnifying lens you are missing out! There is a whole new world to growing plants if you have a magnifying lens. If there is one thing I would recommend to any and all plant growers, it is to get a magnifying lens. It opens the door to a new phase of observation.
Tweezers use to manipulate small flower parts, or use to pollinate if you pluck the whole stamen.*
Small sharp-pointed scissors use to manipulate small flower parts, such as to clip immature anthers on the seed parent.
Small paint brush use to apply pollen grains to the stigma.
Small containers or vials use to collect pollen. I use Petri dishes, they are large so pollen is easy to collect and shallow so that pollen is easy to get at when you are pollinating. They are also easy to label and store in the refrigerator to use over several days. You can get them at many stores (a simple search on Google for “petri dish buy” and you can buy 20 for a few dollars). If you sterilize the dishes after use, 20 may be enough for a lifetime.
Alcohol to sterilize equipment and remove pollen before doing another cross. The type I have pictured is inexpensive and at any pharmacy. It is not for drinking the isopropanol in the picture will kill you.
Rubber bands or soft wire to tie shut flowers or tie paper bags onto branches and anything else you can think of...
Paper bags use for pollination and/or to prevent flowers from being pollinated before you choose to pollinate. You can see an example on my “Pollination and Fertilization” 3/16/09 post.
Tags use to label the plants by type or trait. You can buy tags or use tape or write right on the pots like I do with a permanent marker (Scratch out last times information if you reuse your pots). Please, make sure you keep track of pollination information, you won’t remember what you did in a week or a month, trust me. In the end, if you are not 100% sure the seeds have the parents you chose, you must start over.
Notebook – You need to keep track of the parents and their traits so you should take notes, even if it is just a few symbols to help you remember things like DATE PLANTED or POTTED UP DATE or FIRST FLOWER DATE or size (height), branching pattern, time until maturity, or any traits you are trying to breed for . The minimum you should record if you are serious about breeding is the DATE of POLLINATION and the number of seeds harvested and most important thing is DATE of HARVESTING SEEDS.

Good Growing!

Dr. E. R. Myers

3/16/09

Pollination and Fertilization




Pollination -- is the transfer of pollen from an anther* to a stigma*. Pollen is available when a mature anther splits open and releases the pollen. The pollen may be carried to the stigma in numerous ways; the most familiar are via wind and insects. In plant breeding, pollination must be controlled by YOU.
PRE-POLLINATION Before you collect pollen, you need to look at the stigma of the seed parent. It should have either a shinny substance on it that is sticky or a "hairy" surface. (you may need a magnifying lens) It is this substance or surface that catches the pollen, making fertilization possible. If the stigma is not mature (ready) you will not get fertilization (seeds) no matter how much pollen you apply.
When you pollinate you should know high temperatures and moist conditions are harmful to pollen. Try to pollinate when the humidity and temperature are low, usually in the beginning of the day/light cycle. Also, you can pollinate flowers on lower parts of the plant. Here there won’t be the high temperature from the lights. Remember the individual flower that is pollinated does not matter; it is the plant as a whole you want to judge when selecting.
MALES -- If it is physically possible, to help keep down unwanted pollination you should remove male plants, male flowers or male parts of flowers from the room where you will be doing pollination. With perfect flowers you will need to remove all anthers and the stem it sits on a filament (both together are called a stamen*) from the seed parent with tweezers. This gives you a chance to practice plucking the immature stamens on the seed parent since you may want to harvest whole stamens of the pollen parent and use them to pollinate the female.
Fertilization -- is combining male and female sex cells. After you put the pollen on the stigma, the pollen develops a tube which grows downward through the style and into the ovule. Fertilization occurs when the male and female sex cells unite in the ovule. Once fertilization occurs, development of the ovule begins which results in a seed. In other words, you can pollinate the plants (apply pollen to plants) but this does not guarantee fertilization (mixing of male and female DNA) If you are having problems getting seed formation, you may have a self incompatibility or inbreeding problem. I may write about this later, but if you are pollinating and having a problem with fertilization (no seeds) you can E-mail me at askthedoctor@htgsupply.com

POLLINATION with WIND pollinated flowers (plants with numerous small flowers) I often collect the pollen of a few male flowers from the SAME plant. I often snip the whole flower into the bag after I collect a few taps of pollen. For me, it is too much trouble to snip individual anthers with small flowers. Put the pollen in a paper bag and place that on the branch of the chosen female flower (see picture in this post). Be sure to hold the bag up so pollen does not spill out; make sure there are no fans running during pollination. I then give the bag a gentle shake every day for a few days. Make sure the branch can hold the extra weight of the bag, you may need to support the branch with string or tie-wire while the bag is on it. After a few days, take the bag off and see if the flower looks fertilized. Plants that are ANIMAL pollinated those that have a big showy flowers will need to be tested every day when the flowers are maturing to see if the pollen is being made A gentle tap will let you know if the yellow dust is being produced by the anthers. I like to collect the pollen in a small glass vial and apply it to the stigma with a brush. Don’t be afraid to experiment with different methods of pollination. Some people brush the actually anthers on the stigma, try using different types of brushes, different times of pollination (of the day and of stigma maturity) etc.
To sum up, there are three basic ways to pollinate, use a paper bag with pollen, use a small paint brush to apply the pollen powder to the anther, or if you like detail you can hold a stamen with tweezers and brush the anther across the stigma. Either method will deliver a lot of pollen. However you pollinate be careful and precise when you actually do the pollination. If the environment is cool and not too moist nature will take care of the rest.

POST POLLINATION -- After pollination, the seed parent should be protected from contamination by foreign pollen. This is why I often use a paper bag to pollinate; it keeps the good pollen in and the bad pollen out. If you have big flowers with large petals you can try closing the flower. In flowers like morning glories, petunias, or lilies, the petals can be closed around the reproductive organs with a piece of string, or rubber band. You can use whatever you want but you should NOT tear the petals. Some flowers, such as composite flowers, or those that produce multiple long flowers like the Coleus I have pictured in this post… cannot be closed. To protect them from unwanted pollen, you can cover the flower with a paper bag. You may be tempted to use a plastic bag, but I would not recommend it, with the plant giving off water due to photosynthesis a plastic bag over a branch will be good habitat for mold.
Each time you pollinate with a different pollen parent, be sure to first wash with alcohol or hydrogen peroxide the paint brush, tweezers, and anything which might have touched some pollen. Using water to wash your equipment is NOT good enough. This step is very important to prevent pollination of the seed parent with unwanted pollen that has adhered to the equipment. After you wash the instruments, make sure that they are dry or you will kill the pollen that you collect next.

It is very important to label the branch with and information about parents.

Btw, if you happen to be breeding outdoors, you will only need to keep the paper bag or whatever you use to keep unwanted pollen off the seed parent on for a week or so. The longer the better of course, but if rain or wind blows it off after a week most of the pollination should be done. Indoor or out, be sure to observe your plants each day after you pollinate so you can learn to tell as soon as possible if fertilization has occurred. Usually there will be signs that the flower has been fertilized like browning or wilting stigma. Compare this to unpollinated flowers and observe your success.

Good Growing!

3/7/09

Collect Pollen


Flowers that produce pollen tend to make a lot of it. See the yellow powder in the picture in this blog? The yellow powder is pollen, a powdery substance released from male flowers. Pollen is light, and many species have air bladders (think little balloons) on their pollen so it travels on a wisp of air flow. THIS CAN BE A PROBLEM FOR INDOOR GROWERS! One male flower can pollinate all your female flowers; this is not acceptable unless you want a mediocre breeding program.


Collect pollen. As you know from my last post, pollen carries the male DNA and is the plant equivalent of sperm. As a breeder you must select which plant(s) will donate the pollen and which plant(s) will receive the pollen. You must be sure to collect only pollen from the male flower you want, and be sure no other pollen contaminates (pollinates) the female. It may be a good idea to keep the male flowers away from the selected female flowers if you can. If you have plants with separate male and female flowers put the male in a different room; with perfect flowers you need to cut the anthers off the “female” as soon as you can recognize them on the designated female flowers. Choosing who the parents are is absolutely crucial to a good breeding program. To gather the pollen you may be able to simply hold an envelope or vial under a mature anther and gently tap it to collect the pollen. The pollen will be the same in any flower on ONE plant, so you can collect pollen from multiple flowers if they are on the SAME plant. Once you collect the pollen you must apply it to the female flower, the stigma. There are many different types of flowers, so I will break pollination types down into two groups, wind and animal pollinators.

Wind vs. animal pollination. If your plant is insect pollinated, you will need to manually collect pollen and put it directly on the female parts with a small paint brush. If your plant is wind pollinated an easy way to pollinate a female flower is to put the pollen in a brown paper bag, and place the bag over the branch of the female plant to be fertilized. You then give the bad a shake each day for a few days and that is it. If you want, you can also use a small paintbrush to apply the pollen to the female flower of wind pollinated plants too. Some people find it makes them feel more involved and intimate when they do the pollination, and you should enjoy your hobby.

How do you know if you plant is wind or animal pollinated? Plants with wind pollinated flowers tend to have flowers that are small and/or not easily seen. Wind pollinated plants typically produce large amounts of pollen. On the other hand, plants with big showy flowers tend to make less pollen and are pollinated by an animal of some sort (usually insects). This makes sense if you think about it, a flower is trying to get something’s attention, but a plant like corn or your grass does not need to waste energy in making a structure to attract the wind. If it uses a lot of energy, why do any plants make flowers then? The benefit to putting energy into a big showy flower and being pollinated by an animal is that animals will go directly from one flowering plant to the next; making pollination much more successful. The wind will carry pollen which ever way the wind may blow, so wind pollinated plants need to use more energy to make A LOT of pollen. If you live near pine trees you know how pollen “yellow dust” can cover any and everything outside in a good spring.

Pollen is like beer, you need to wait until it is done, but it is best when fresh. I recomend you use pollen the day you harvest it. I believe most pollen will remain viable for a few days at room temperature. You can freeze pollen and use it over multiple generations, as a form of a back cross (more on breeding later). The success of fertilization will decrease over time I imagine, so store a lot more pollen than you plan to use. In general, pollen is smaller and has a shorter life span than seeds but you can store it the same as seeds (see post on 2/06/09 seed storage) For longer storage of pollen you can place the pollen in an air tight container in the freezer for up to a year. It may last longer than a year, but I have never tested that. Once you get good at pollination, you could pollinate one female plant with several different pollen parents. Be sure to label each cross carefully. This would allow you to try several crosses during one flowering period. You can then grow the different varieties and select which are the best for your growing needs.

Next blog I will talk about how to apply pollen, and then different breeding techniques.

Good Growing!