Location: Crop Genetics and Breeding ResearchTitle: Heritability of drought resistance traits and correlation of drought resistance and agronomic traits in peanut Author
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2009
Publication Date: 11/20/2009
Citation: Songsri, P., Jogloy, S., Kesmala, T., Vorasoot, N., Akkasaeng, C., Patanothai, A., Holbrook Jr, C.C. 2009. Heritability of drought resistance traits and correlation of drought resistance and agronomic traits in peanut. Crop Science. 48:2245-2253. Interpretive Summary: Drought is a major limitation for peanut productivity and quality throughout the world. The objective of this study was to estimate the heritability of drought resistance traits under drought stressed and non-stressed conditions. A large populations of peanut breeding lines from four crosses were tested under full and reduced irrigation. Data were recorded for several physiological traits that might be related to drought tolerance. Several of these measurements were highly heritable and were correlated with pod yield under drought stress. The chlorophyll meter reading is easy and inexpensive to measure, and may be useful as a selection trait for breeding peanut with improved drought tolerance.
Technical Abstract: Inheritance of traits is important for developing effective breeding schemes for improving desired traits. The aims of this study were to estimate the heritabilities (h2) of drought resistance traits and the genotypic (rG) and phenotypic (rP) correlations between drought resistance traits under stressed and nonstressed conditions. The 140 lines in the F4:7 and the F4:9 generations from four peanut (Arachis hypogaea L.) crosses were tested under field (FC) and two-thirds available soil water (2/3 AW) in two field experiments. Data were recorded for specific leaf area (SLA), SPAD chlorophyll meter readings (SCMR), biomass, pod yield, harvest index, number of mature pods per plant, seed per pod, and seed size. The h2 for biomass, pod yield, DTI (drought tolerant index) (pod yield), DTI (biomass), HI, SLA, and SCMR were high for all tested crosses (0.54-0.98). The rG (-0.61 and -0.66) and rP (-0.61 and -0.66) between SLA and SCMR were strong and negative under 2/3 AW and FC. Under 2/3 AW conditions, SCMR was positively correlated with pod yield and seed size. Compared to SLA, SCMR had higher rG and rP with pod yield, biomass, and other agronomic traits. Significant correlations between FC and 2/3 AW conditions were found for pod yield, biomass, SCMR, and SLA, indicating that these traits could be selected under FC or 2/3 AW conditions. SPAD cholorophyll meter reading, which is easy to measure, is potentially useful as a selection trait for drought resistance because of high h2 and positive correlation with pod yield and agronomic traits.