VICTORY GARDEN

Now is the time of year to start you summer VICTORY GARDEN indoors. Tie your indoor hobby with an outdoor VICTORY GARDEN by giving your seedlings a head start indoors for the summer with 24hrs light and the right amount of water and temperature. Be sure to read my article  before putting your plants outdoors, or you maybe disappointed.

Good Growing!

Dr. E. R. Myers

HOW TO BREED PLANTS Which technique is best for you?

As you know, breeding involves bringing pollen to the seed plant. One can look at pollen transfer in two ways, cross-pollination and self-pollination. Both have their importance in the science of plant breeding. With cross-pollination the pollen is transferred from one plant to another plant. In self-pollination the pollen is transferred within the same flower or to another flower of the same plant. If you can self pollinate plants you will have a much better chance of getting a pure breeding seed population in a few generations. However, self pollination does not allow you to combine two different traits. And, even if you have a superior plant, with some species you may have problems with self-pollination, i.e. not getting seeds. Some plants must be cross pollinated to produce seeds.
With cross-pollination you try to combine two excellent traits from two parents. Both parents can have the same trait say big flowers, or you can try to combine two different traits into one plant like if you cross a short plant with one that produces huge flowers to try and get a short plant with big beautiful flowers. The problem with crossing two plants is that in most cases you get a lot more variety in the next generation (a lot of tall plants with small flowers and other unwanted things that were not even in your parent plants). This gives you more options to select your prize winner from, but more plants will need to be grown. So, with all breeding you must start with the best plants you have. In breeding you do not build up, you only peel away to expose what is already there.
The keystone of breeding is Heritability – You can look at how traits are inherited in two basic ways: 1) Quantitative traits that occur along a scale or gradient, like yield and plant height 2)Discrete traits which occur with no scale, flower color for example where the flowers are red OR yellow. Discrete means there is a definite beginning and end, no in-between. With quantitative traits there is not just 1 or 2 but you will have 1.1 and 1.2 and 1.75 etc. Quantitative traits can often be attributed to the interactions between two or more genes and their environment. They are involved in important agricultural traits such as crop yield, flower diameter, number of flower parts, and in animals, weight gain, and fat content of meat are quantitative traits, as well as human traits like IQ, learning ability and blood pressure.

Some traits are easily inherited, others not so much. Easily inherited means you can breed plants with a trait and the offspring will have the same trait you want. Some traits are not easily inherited because they only occur under certain environmental conditions. Be mindful, as an indoor grower or gardener, you provide the environment. The environment you provide is important! You may never get flowers to bloom big w/o certain fertilizers (phosphorus). However, most of the time you will deal with a mixture of genetics and environment. This means that some fertilizers may make one plant flower and grow superbly, and the same fertilizer may only make another plant average at best. This is why I always advise experimenting with new products, and why it is important to keep notes over time, to compare and find what is best for your plants in your space.
As a breeder, you need to be observant, take notes and have a goal. It does not involve a lot more work than just growing plants, you just need consistent observations. Write down dates and traits when they occur, be precise. Other than that, each individual grower decides what they want to breed for, big flowers, a mild yet flavorful pepper, tomato’s that fit perfectly on a slice of bread. Be mindful of why you grow, and then breed your plants to be what you want. I will present three basic breeding strategies; pick the one that best suits you.

1. Backcross breeding -- This is used to introduce or improve one trait. This is NOT effective with quantitative traits. A cross is made between the donor and the recipient parents. In general the donor will have a trait that you want to introduce into the recipient parent. The recipient should be an awesome plant and the donor should have a trait that you want to introduce or incorporate in the recipient plant. You then cross the F1 generation (back to) with the recipient parent. The genetic contribution of the donor will be halved each generation. For example -- The F1 will have only 50% recipient plant genetics, but the first backcross BC1 will have 87.5% of the recipients genes the BC2 will have 93.75% and the BC3 will have 96.87%. So you will be close to the original recipient with a new trait introduced with three backcrosses. BENEFITS are that you can repeat the results easily, and few records are needed. The problem is this works well only with discrete traits.

Example of back cross breeding. You grow a variety of sweet bell pepper, and you want to make it resistant to fungal attack. You can cross your sweet pepper with a pepper that does not get the rot to try to introduce the resistance. You then need to grow the F1 generation and cross it with the original sweet pepper (or genetically identical seeds to that sweet pepper). You cross the F1 plants that are resistant with the original sweet pepper and then cross the BC1, BC2 etc. with the sweet pepper until you get the original pepper that is also resistant to rot.

2. Mass/recurrent selection -- This is the most effective breeding strategy for quantitative traits like yield and plant size. This is the most effective in cross pollinators as well. If you think about it, this is common sense breeding, you pick the plants that have the best traits as parents for the next generation. For example, if you want shorter plants, you pick the shortest plants as the parents. As with all breeding techniques, the success of this depends on the heritability of the trait. This type of breeding is often used to rogue out poor types of plants to improve your plant population: remove the weak and inferior plants. BENEFIT- easy to do. COST takes a long time (many generations) to this I say, “If you start off with plants you enjoy it will be a fun journey improving what you have.”

Example of recurrent selection --As an indoor grower, you have special needs and restrictions on your plants, most notably space. A common indoor trait would be to select for plants that are short. To breed a population of plants that are short, you would select a male and female parent that is short. From their seeds you grow many plants and pick the shortest plants as the next parents. You continue this until all plants are as short as you want. Recurrent breeding begins with “best” plants --> 1. Evaluate progeny and pick best for breeding, --> 2. Propagate next population --> 3. Evaluate progeny and pick best for breeding -->4. Propagate next population --> go back to 1.

3. If you are working with traits that seem to have low heritability, and you just can’t get the trait to breed consistently into the next generation you can use something called SINGLE SEED DESCENT (SSD) which involves growing (descending) one seed per plant each generation. By doing SSD over multiple generations it is possible to create a population of genetically identical seeds. After at least five generations (F5) and if each generation has the trait you want then in the F6 you can bulk up, meaning produce a lot of seeds all of which will be genetically identical. Only now can you say that you have your own seeds. This is what you are buying when you buy a packet of seeds, time and energy. You can see that plant breeding takes time. If you enjoy it, it is not a burden, but a hobby. The BENEFIT of using SSC is you will end up with a large consistent population of seeds that have the trait you desire. The cost is that it will take several generations and you risk loosing all your work if something happens to that one seed/plant during the process before you can bulk up. You can store seed from the original parent or each generation (See seed storage) and if you loose the traits, or the plant dies, you can start over. But you are always choosing one seed to start the next generation with.
Example of SSD. You have a hot chilli pepper that you love and want to grow many more of them. You let it self pollinate. Choose one seed as the offspring, and if it has the same trait as the parent, let it self and grow its offspring. If you get plants you like each generation (there is no loss of the desired trait) after 5 generations you have a PURE BREEDING* plant. You can bulk up (Make a lot of seeds) and say with confidence that the seeds and plants that come from them will all be the same.
The art of breeding is creating a plant that best fits to your environment. If you start your own breeding program, you will be the one to choose what you like. I hope you find success with the above information, and of course you can modify these as you see fit. As always, feel free to post a comment or E-mail me a question.
Good Growing,
Dr. E. R. Myers

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

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!