Methods to improve seeds 1. Selection – take individual plants and pick the best plants from them...

Methods to improve seeds1. Selection – take individual plants and pick the best plants from them and plant their seeds.

2. Directed Breeding – cross two plants together in order to get hybrid vigor to better the crop.

3. Gene Splicing – slicing out a section of a plant and putting it into a totally different plant. GMO’s

How is this breeding accomplished?

In the chromosomes the genetic characterists are contained in genes. And they produce enzymes which produce protein. These proteins have an effect on DNA and RNA.

Terms1. Genotype – Genetic make up of the plant. Not always visible.

2. Phenotype – Physical make up of the gene combinations. What you can see.

3. Sexual Reproduction – Gametes Diploid (2n) pair of chromosomes Haploid (1n) a single chromosome

4. Alleles – same location on a gene of

a chromosome.5. Homozygous – same gametes.6. Heterozygous – different gamets.7. Dominate trait – mask another.8. Recessive trait – only seen when

paired together.9. Recessive trait – only seen when

paired together

10. Mitosis – Cell division, makingdiploid cells , normal growth,daughter cells the same as

theparent cell.

11. Meiosis – sexual reproductionthrough division.

12. Pollination – the transfer, movement, of pollen grains

from theanther to the stigma.

13. Hybrid – is an offspring of a cross oftwo different genetic parents of the same species. +’s Highly uniform, increased vigor, increased yields, verypredictable.-’s Can’t reuse seed, expensive,

more locally adapted, may or may not have as much disease res. As O.P.’s

Flowers1. Contain organs for specialized sexual production2. Produce seeds and fruit

Parts of the FlowerSepals

Outer covering of the flower budProtects the stamens and pistils when flower is in bud stage

Parts of the FlowerPetals

Brightly coloredProtects stamen and pistilsAttracts pollinating insects

Parts of the FlowerStamens

Male Reproductive partAnther-produces pollenFilament-supports the anther

Parts of the FlowerPistil

Female reproductive partOvary

Enlarged portion at base of pistilProduces ovules which develop into seeds

StigmaHolds the pollen grains

Parts of the FlowerStyle

Connects the stigma with ovarySupports the stigma so that it can be pollinated

Complete and Incomplete Flowers

Complete: have all four main partsSepalsPetalsStamensPistils

Some plants have both male & female flowers

1. Monoecious – plants contain bothmale and female flowers.

2. Dioecious – plants contain only one sex and another plant contains counter part. Male plants and female plants.

3. Gynecious – only female and very few male flowers.

4. Andromonecious – only male and very few female flowerws.

Methods of pollination1. Self Pollination – Pollinates themselves.2. Cross Pollination – due to wind, animals, or insects plants pollinated by other plants.

Plant Improvements, How does man manipulate

plants?1. Render the pollen non-viable

Male sterilityEmasculation – remove or kill anther.

2. Selection – A process in which you pick certain plants to reproduce.

3. Rouging – to pick out a few plants and cull them out and keep the remaining plants.

4. Mass Selection – take a sample from a population and grow it for seed production.

Heterosis (Hybrid Vigor) - cross two plants and get an offspring that will be superior to its parents.

Inbreeding Depression – the vigor of that crop goes down dramatically.

To get a select line – you must isolate the crop so they can’t pollinate by any other crop. Also put up cages to keep insects out. Cover stigmas with bags.

Hybrid – is an offspring of a cross of to different genetic parents of the same species.+’s = Highly uniform, very predictable,

vigor increases, yield increases

-’s = Can’t reuse seed, expensive, more locally adapted, may or may not have as much disease resist. as O.P.

Vegetative propagationExamples of plants –

GarlicRhubarbArtichokesPotatoSweet Potato