Breeding Systems Flashcards
What is apomixis?
A type of clonal reproduction
Methods of species that promote outbreeding?
Separation of the sexes
Self incompatibility
What is agamospermy?
Seeds without sex
What problems can inbreeding cause?
Loss of vigour
Loss of fertility
Homozygosity for deleterious recessives
What is dichogamy?
Separation of the sexes in time to prevent self-fertilisation
What is dicliny?
Separation of the sexes in space to prevent self-fertilisation
What are the advantages of selfing?
A guaranteed seed set
Independent of pollinators
No stigma blocking by incompatible pollen
High seed output, useful for colonising species
Reduction of genetic variation
Different homozygous lines can be selected for different habitats
What are the key traits of plants with homomorphic gametophytic self incompatibility?
1 morph Single locus with multiple alleles Binucleate pollen Pollen has a low respiration rate Wet stigma Gappy cuticle
In homomorphic gametophytic self incompatibility what would happen if S1 and S3 landed on an S1S2 stigma?
50% probability fertilisation
What are the key traits of homomorphic sporophytic self incompatible plants?
Only one morph Single locus with multiple alleles Trinucleate pollen Dry stigma Pollen has a high respiration rate
In homomorphic sporophytic self incompatible plants would an S1S2 ovule be fertilised by S1S3?
No, not at all
What type of self-incompatibility does the primula exhibit?
Heteromorphic
What is the genetic code for a Pin primula?
ggppaa
What is the genetic code for a thrum primula?
GgPpAa
If a plant is dioecious how much of the population is available to mate with?
50%
