food security 4 Flashcards
food security, crop and breeding improvement and genetic resources (24 cards)
key factors to maintain food and nutritional security and income for farms
genetic diversity on-farm (range of species of crops, cattle etc)
this is important for culture, economic benefit (niche market, environmentally sustainable
enables seed system within farm
farmers maintaining this system
interventions to maintain genetic diversity on-farm
conservation: Ex situ/In situ
policies: local, national funding for farmers to maintain genetically diverse crop or breeds
value addition: processing, markets, awareness
crop improvement: breeding, agronomy, use of GR
how new crop varieties and improved breeds are created using GR: breeding
(un)conscious selection for desired traits
conventional breeding in Europe in the 19th C
genomic based breeding in the last 50 years genetics, genomics GMOs
how new crop varieties and improved breeds are created using GR: domestication
animals about 10 000 years ago: first dog and goat
plants about 8 000 years ago
about 7 000 crops grown today
total 14000 but many very localised
agricultural homelands animals
earliest in Near East: Türkiye, Syria Iraq
also New Guinea and China then America
agricultural homelands: plants
8 centres of diversity/origin discovered in 1926
4 additional centres discovered in 2021
traditional breeding
farm based
landraces
at the end of each season superior plants are used for next growing cycle
exchange of seed/semen with friends or local markets
landraces
locally adapted variety of domesticated plant e.g. Shetland Kale
formal breeding: Mendel
19th C Monk Mendel
homo and heterozygous
law of independent assortment, random selection of alleles
recessive, dominant, codominant etc
implications of formal breeding
higher productivity
higher quality e.g. inc nutritional value
maximum efficacy e.g. shorter growing season or less space
improved marketable traits e.g. taste and appearance
conventional (non-GMO) breeding: hybridisation
offspring is a product of parent plants genetic traits, can be same or different species
a way of combining beneficial genetic traits
may involve chromosome manipulation and embryo rescue
cultivars
cultivated plant varieties formally approved and registered (very undiverse, almost homogenous)
breeding lines
highly bred material, not commercially released by has characteristics sought for a particular environment or plant
obsolete types
suspended material that are no longer used by the community
landraces
unique varieties of crops or breeds that are genetically heterogenous and have adapted to local conditions through farmer selection e.g. Shetland kale
primitive forms
crop varieties not subjected to intensive breeding or growers selection; they have features or traits that are similar to wild relatives
wild relatives
wild species related to crops or breeds, including progenitors (origin species)
PGRA
Plant Genetic Resources for Food and Agriculture
germplasm: genetic resources for plant breeding
GRFA is a unique resource
crucial to sustain food security
human made over millennia
explicit link between conservation and use
diversity focused in the Vavilov centres of diversity
focus on conserving intra-specific diversity
significant inter-dependence between countries
recurrent backcross
backcross (with older species, normally parent) when cultivar loses useful trait e.g. pest resistance
repeated backcrossing (6 or 7 cycles) gets old variety with new beneficial trait
GMO breeding
genetic modification
expensive
technical
intra-species or inter-species allele transfer
targeted and quick
transgenic GMO modification
a gene is moved from one non-closely related species to another
cisgenic/intragenic
a gene is moved within the same species or closely related species
subgenic
a gene is edited to amplify, delete, insert silence or repress the gene
