Leguminosae Flashcards
What is the legume paradox in Switzerland?
Third place globally in producing negative externalities
Agriculture accounts for more than 14.5% of greenhouse gas emissions, thereof livestock produces about 85% of the 6.34 Mio t CO2eq
Soybean import on areas equaling 100’000 ha while producing soybean on 1800ha, despite big potential for legumes
Estimated potential of grain legumes in Switzerland
Moderate ~290’000 ha
Maximal ~510’000 ha
Characteristics of Leguminosae
About 20’000 species
Unusual flower structure
Podded fruit
Compound leaves
Most species form nodules with rhizobia
Grain legumes:
- economical importance, second after Poaceae
- For human consumption and fodder
- Nutritious sources of protein, fiber and micronutrients, especially iron
- less improvement in crop yields compared to cereals
Family Leguminosae or Fabaceae
Third largest land plant family
Six subfamilies, of agricultural interest:
Caesalpiniodeae (agro-foresty)
Faboideae (grain legumes)
- genus Phaseolus - P.vulgaris (common bean)
- genus Vicia - Pisum sativum
Phylogeny of the Genus Phaseolus
About 75 species which grow in wide range of environments
8 clades with some morphological, ecological or biogeographical distinction
5 domesticated species
Mostly self-pollination, except P. coccineus (and P. lunatus)
Biological species concept
Proposed by Ernst Mayer in 1904
A species is a population of organisms that can interbreed and produce healthy offspring
They cannot breed with other species
Gene pool concept in crop breeding
Primary gene pool: Varieties of the same species that can intermate freely
Secondary gene pool: Closely related species that can intercross with GP-1 and produce at least some fertile hybrids
Tertiary gene pool: Distantly related species that can intercross with GP-1 and -2 but requires additional measures such as embryo rescue or chromosome doubling to obtain offspring
Phaseolus vulgaris: the common bean
diverged ~8000 years ago into Mesoamerican and Andean genepool
Bush (determinante flowering) and climbing habit
- intercropping or monoculture
From 0 up to 3000m above sea level
Eaten as vegetable (pod) or seeds
- 20 - 25% protein, 50 - 100 mg/kg iron
Most important grain legume for direct human consumption
- global production ~12 Mio. tonnes/year
Self-pollinating
- Genome size: 587 Mb (2n = 2x = 22)
P. dumosus: year-long bean
Origins from the highlands in Guatemala
Traits from P. coccineus (semi-tuberous root, large seeds) and P. vulgaris (epigeal cotyledons)
Perennial or semi-perennial
Traits for climate change adaptation including: tolerance to wet and high-altitude conditions
Disease resistance such as ascochyta leaf blight, anthracnosis and white mould
Phaseolus acutifolius: tepary bean
Drought resistant - long and thin roots; drought responsive genes
- production in semi-arid climate in Kenya
Disease resistant genotypes against bean weevil, bacterial blight and fusarium
- tertiary gene pool of common beans, e.g. transfer of bacterial blight resistance and drought resistance
Butlow yielding and abiotic stress-susceptible cultivars
Yield 1 to 1.5 t/ha; ~24% protein
Short cooking time
Seed quality similar to common bean
Bean breeding program at CIAT
Phaseolus vulgaris: Diversity of the breeding material
Big phenotypic diversity in growth habit, days to flowering (DF), 100 g seed weight (100SdW), seed iron concentration and yield
Genetic diversity of Andean, Andean x Mesoamerican, Mesoamerican, climbers and elite bush lines based on 15’000 molecular markers and 1869 lines
Phaseolus vulgaris in Europe
Arrived multiple times in Europe (first time around 1500)
both Andean and Mesoamerican gene pool is present
in CH:
genetic improvement of the Schwefelbohne:
traditional bean variety of the Rheintal will be bred for determinate growth type / uniform maturity, seed color, virus resistance
Phaseolus lunatus L.: Lima bean
Two or three genepools emerged from domestication in Mexico
Determinate bush types and indeterminate climbing types
Cultivated mainly in Cameroon; increasingly in semi-arid zones of Brazil
Abiotic constraints include heat, acaidity, salt stress, water deficit and wind
Biotic onstraints: nematodes, viruses such as Bean Common Mosaic Virus, bacteria nd insects
Phaseolus lunatus L.: Genetic improvement
Deep root sysem and water deficit tolerance
Biotic and abiotic stress tolerance
Pedigree breeding program at Delaware University
