plant breeding Flashcards
what is plant breeding
changing the genetics of a plant to benefit us
many traits that were selected because they fit the needs or fancy of humans are actually deleterious in the wild. fully domesticated crops may not survive in the wild without human help
what are some examples of how plant breeding is done
there are many different techniques ranging from simply selecting plants with desirable characteristics to more complex molecular techniques (DNA)
what are some traits that breeders have incorporated into crops over the last 100 years
- increased yield
- encreased tolerance of environmental pressures (extreme temperatures, drought)
- resistance to plant diseases
- increased tolerance to pests
- tolerance to herbicibes
- nutritional or medical production
what are the two types of plant breeding
- classic
- molecular(based on genetic information)
what does classic plant breeding refer to
- taking pollen of one selected plant and transferring it to your selected female plant
- introducing new genes to the plant DNA
- studying the genes of the plant
how is classic plant breeding done
classic plant breeding uses deliberate interbreeding to produce new crop varieties with a desirable trait
classical breeding is through sexual means, ie, after fertilization of an ovule in a female parent by a sperm cell contained in pollen grain produced by a male parent
the new result is new genetic combinations
what is a phenotype
it is an observable characteristic or trait of an organism and is the result of the expression of an organism’s genes and well as the influence of the environment
what is a genotype
the genetic constitution of an organism
what is genomics
the study of a plants genome to better understand the workings of the plant and what happens when certain genes interact with each other and the environment
what is molecular breeding
- it’s based on the genotype (genetics only no interaction from the environment)
- it is the application of molecular biology tools in plant breeding
what are two examples of molecular breeding
- marker-assisted selection
- genetic engineering
what is a marker-assisted selection
-category of molecular breeding and is a tool for plant breeders
how are molecular markers used
- first breeders must find the molecular marker
- a molecular marker is a fragment of DNA that is associated with a certain location within the genome
- molecular markers are used to flag the position of a particular gene or the inheritance of a particular characteristic
- the characteristics of interest are linked with molecular markers. thus individuals can be selected in which the molecular marker is present since the maker indicates the presents of the desired characteristics
- the result is that molecular markers can map the genes of a plant
what is the benefit of using marker-assisted selection
- it allows plant breeders to screen a large number of plants for those that possess the trait of interest
- greatly reduces the fieldwork and produces new crop varieties faster
- based on the presents or absence of a certain marker linked to a gene rather than on the visual identification of the expressed trait in the plant
- false positives slow plant breeding
what is GMO and transgenic
the use of the term genetically modified organism is used to designate genetically engineered crops
