Description

A poster presented at the 2012 Global Pulse Researchers Meeting, Kigali, Rwanda- “Transforming Grain-Legume Systems to Enhance Nutrition and Livelihoods”. Abstract: Low phosphorus (P) availability and drought are major constraints to common bean production in many developing countries. The root system is an important factor for plant productivity. Bean genotypes with shallow roots, large number of basal and adventitious roots have advantages in acquiring P from low P soils, while genotypes with deeper and longer roots will acquire water from deeper soil horizons. Information on root diversity is crucial for development of varieties adapted to a specific region. To assess the diversity of root phenes in beans, 165 accessions from the bean core collection from CIAT were planted in the laboratory and field in Pennsylvania, USA. Substantial variation in root traits between and within gene pools in adventitious, basal and primary root traits was found. The root hair length (RHL) varied from 0.19 to 0.78mm. Twenty one percent of the 165 accessions had long root hairs. RHL and density were positively correlated (R2 = 0.69). Significant differences between and within gene pools were detected for most root phenes. We found tradeoffs between adventitious and basal roots. Useful root traits for breeding for edaphic stresses were identified in both Andean and Mesoamerican gene pools. Breeding for multiple root phenes could enhance acquisition of multiple soil resources, particularly in developing countries.