Dissertation
LOW SOIL FERTILITY AND DROUGHT STRESS TOLERANCE IN SELECTED ANDEAN COMMON BEAN (PHASEOLUS VULGARIS L.) GENOTYPES
Doctor of Philosophy (PhD), Washington State University
01/2017
Handle:
https://hdl.handle.net/2376/117299
Abstract
Common bean (Phaseolus vulgaris L.) is an important food legume cultivated in all major continental areas. Low soil fertility in particular low nitrogen (N), low phosphorus (P) and drought stresses are the major limitations to dry bean production in developing countries. Identifying genotypes representing new and diverse sources for low soil fertility and drought stress in Andean diversity panel (ADP) will contribute toward breeding for bean productivity in developing countries. A panel of 268 genotypes and varieties were evaluated from 2013 – 2015 in Tanzania and Washington (WA). Phenotypic traits measured included days to flowering maturity, harvest maturity, canopy height (cm), plant biomass rating (1-9), root and shoot dry weight (g), number of nodules per plant, pod harvest index (PHI), seed weight (g 100 seeds-1), pods plant-1, seeds pod-1, and seed yield (kg ha-1). In Tanzania, yield was significantly influenced by yield component traits and partitioning traits. Yield obtained from bean with bush growth habit was significantly higher than vine under low soil fertility. In WA, results indicate that genotypes with vine growth habit had some level of tolerance to drought stress compared to bush type. Canopy height, biomass, flowering maturity and harvest maturity significantly influenced yield. Significant environment (E), genotype (G) and genotype x environment (GE) effects on seed yield were detected using GGE-Biplot analysis. Four ADP genotypes in Tanzania and four genotypes in WA were identified as stable across environments thus will be useful in breeding for general adaptation. GWAS analysis identified QTL for most of the traits measured under low soil fertility and drought stress. These QTL were distributed across all eleven chromosomes and provide preliminary information for traits affected by stress. Results for glasshouse experiment for Phosphorus use efficiency (PUE) indicate variation among all traits measured which included shoot biomass (g), shoot P (mg kg-1), root P (mg kg-1), seed P (mg kg-1) and seed yield. The trait values increased with increasing P levels. It was observed that genotypes with higher PUE under limiting P may be useful for improving bean productivity under such condition.
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Details
- Title
- LOW SOIL FERTILITY AND DROUGHT STRESS TOLERANCE IN SELECTED ANDEAN COMMON BEAN (PHASEOLUS VULGARIS L.) GENOTYPES
- Creators
- Eninka John Mndolwa
- Contributors
- Phil N Miklas (Advisor)Lynne C Boggs (Committee Member)Kim Campbell (Committee Member)Hal Colllins (Committee Member)Steve Fransen (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Crop and Soil Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 215
- Identifiers
- 99900581517401842
- Language
- English
- Resource Type
- Dissertation