Location: Crop Genetics and Breeding ResearchTitle: Inheritance of the physiological traits for drought reistance under terminal drought conditions and genotypic correlations with agronomic traits in peanut) Author
Submitted to: Society for Advancement of Breeding Researches in Asia and Oceania
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/1/2013
Publication Date: 5/1/2013
Citation: Girdthai, T., Jogloy, S., Vorasoot, N., Akkasaeng, C., Wongkaew, S., Patanothai, A., Holbrook Jr, C.C. 2013. Inheritance of the physiological traits for drought reistance under terminal drought conditions and genotypic correlations with agronomic traits in peanut. Society for Advancement of Breeding Researches in Asia and Oceania Journal of Breeding and Genetics. 44:240-262. Interpretive Summary: Improvement of drought tolerance in peanut would greatly benefit farmers in rainfed regions where drought is a major constraint limiting yield and quality. The objective of this study were to evaluate the association between drought resistant traits and yield traits in peanut. Field experiments were conducted for two years. Strong associations were found between drought resistant traits and agronomic traits. These results indicated that physiological-based selection approaches might be used to accelerate efforts in breeding peanut for improved terminal drought tolerance.
Technical Abstract: Breeding for terminal drought resistance in peanut can increase their productivity in drought-prone environments and reduce aflatoxin contamination. To improve selection efficiency for superior drought-resistant genotypes, a study of inheritance of traits is worthy, and provides useful information for planning suitable breeding approaches. The objectives of this study were to estimate the heritability of terminal drought resistance traits, the genotypic and phenotypic correlations between drought resistance traits and agronomic traits, and among physiological traits in peanut. The 140 peanut lines in the F4:6 and F4:7 generations were generated from four crosses (ICGV 98348 x Tainan 9, ICGV 98348 x KK60-3, ICGV 98353 x Tainan 9, and ICGV 98353 x KK60-3), and tested under well-watered and terminal drought conditions. Field experiments were conducted under the dry seasons 2006/2007 and 2007/2008 in the Northeast of Thailand. Data were recorded for agronomic traits [biomass, pod yield, number of mature pods per plant, seeds per pod, and seed size] and physiological traits [harvest index (HI), SPAD chlorophyll meter reading (SCMR), and specific leaf area (SLA)]. The heritability estimates for physiological traits were higher than for agronomic traits, and varied among crosses. The heritability for HI, SCMR, and SLA ranged from 0.55 to 0.85, 0.72 to 0.91, and 0.61 to 0.90, respectively. Positive correlation between HI and SCMR were significant, and SLA was also found to be inversely associated with SCMR and HI. Significant and positive correlations between HI and SCMR with most of agronomic traits were found. SLA was also negatively correlated with agronomic traits. These results indicated that HI, SLA, and SCMR are potentially useful as indirect selection traits for terminal drought resistance because of high heritability and good correlation with pod yield. Plant breeding approaches using these traits might be effective and valuable for improving terminal drought tolerance in peanut.