The genetic control of tolerance to aluminum toxicity in the ‘Essex’ by ‘Forrest’ recombinant inbred line population

Abstract

Aluminum (Al) toxicity to plant roots is a major problem of acidic soils. The main chemical reaction involved is Al hydrolysis. Application of lime or nitrate fertilizers to raise soil pH reduces Al toxicity but not as economically as a plant genotypes with natural tolerance against this stress. Ammonium fertilization of crops and assimilation of ammonium (even that derived from dinitrogen) are particularly acidifying of the root zone. The aims of the present study were to find genotypes of soybean tolerant to aluminum stress and identify QTL underlying that trait. Used were recombinant inbred lines (RILs) derived from the cross of 'Essex' by 'Forrest'. RILs were grown in a greenhouse for 3 weeks and then transferred to hydroponics in a growth chamber. Root lengths (RL) were measured before and 72 h after Al treatment. RL before and after Al treatment were measured and used to calculate root tolerance index (RTI) and relative mean growth (RMG). RILs 1, 85, 40 and 83 had significant (P<0.005) tolerance to Al stress judged by RL after Al, RTI and RMG. Eleven minor but significant marker-trait associations (P<0.05) were detected using one-way ANOVA but only two major loci were significant in composite interval maps (LOD>3.0). The QTL on linkage group F (chromosome 13) was in the interval Satt160-Satt252 with a peak at 24 cM (peak LOD was 3.3). The QTL underlay 31% of trait variation and the Essex allele provided an additional 1.61 cm of root growth over 72 h in the presence of Al. The QTL on linkage group C2 (probably chromosome 4) was in the interval from Satt202 to Satt371 with a peak at 3.2 cM (peak LOD was 14.7). The QTL underlay 34% of trait variation or 1.81 cm of growth over 72 h in the presence of Al. Both loci encompassed genes implicated in citrate metabolism, a method of aluminum detoxification known to vary among soybean cultivars. Two major loci and at least nine minor loci were inferred to underlie tolerance to Al. RILs and markers may be used to select alleles that increase tolerance to soybean against Al stress.

Epistatic Association Mapping for Alkaline and Salinity Tolerance Traits in the Soybean Germination Stage

“…Sharma et al [48] identified two major QTL for tolerance to Al. These two QTL were also detected in the present study and were located in the marker intervals satt160-satt252 (F) and satt202-satt371 (C2), respectively.…”

Quantitative trait loci mapping of resistance to aluminum toxicity in common bean

“…Multiple QTL with major and minor effects have been reported to control Al resistance in Arabidopsis (Hoekenga et al., 2003; Kobayashi & Koyama, 2002; Kobayashi, Furuta, Ohno, Hara, & Koyama, 2005), sorghum [ Sorghum bicolor (L.) Moench] (Magalhaes et al., 2004), rice ( Oryza sativa L.) (Nguyen et al., 2002), maize ( Zea mays L.) (Ninamango‐Cardenas et al., 2003), and soybean [ Glycine max (L.) Merr.] (Bianchi‐Hall et al., 2000; Korir, Zhang, Wu, Zhao, & Gai, 2013; Sharma, Sharma, & Lightfoot, 2011). Genetic variation in Al resistance has been reported in common bean (Blair, Lopez‐Marin, & Rao, 2009; Butare et al., 2011).…”

Liming and Nitrogen Fertilization Effects on Soil Microbial Community in Long Term No-till

“…A possible explanation lies on NH4NO3-N applications. The increase in soil acidity with the use of ammoniacal fertilizers is caused by the nitrification process, the oxidation of NH4 + to NO3releases H + protons, which occupy cation exchange sites leached with NO3 -, reducing the soil pH [27,28]. The high values of Al 3+ observed in N fertilized treatments also match with lower pH values.…”

“…Liming has long been reported as an efficient way to reduce soil acidity in both conventional and NT systems [8,9]; this fact was observed in the treatments with liming as Oat-L and Oat-NL in which the soil pH increased and, consequently, the Al 3+ contents were lower. Increasing soil pH with liming favors a reductions in Al 3+ content due to its precipitation as Al(OH)3 [28].…”