QTL Mapping of Adventitious Root Formation under Flooding Conditions in Tropical Maize (Zea mays L.) Seedlings

Abstract

Quantitative trait loci (QTLs) controlling adventitious root formation (ARF) on the soil surface were evaluated under flooding conditions in 110 individuals of an F 2 population derived from a cross between a dent inbred line 'B64' and a tropical Caribbean flint inbred line 'Na4'. The ARF capacity of seedlings suggested the existence of continuous variation in the F 2 population. The QTLs for ARF were located on chromosomes 3 (bin 3.07-8), 7 (bin 7.04-5) and 8 (bin 8.05). Alleles of line Na4, with a high capacity for ARF, increased ARF in the case of all the QTLs. By comparing chromosome positions of ARF loci in the B64 × Na4 population with those in a B64 × teosinte (Zea mays ssp. huehuetenangensis) population, the region conditioning ARF on chromosome 8 was consistent across the two populations. In the present study, overlap between the QTLs for ARF in the B64 × Na4 cross and QTLs for root traits measured in aerated hydroponic culture was also observed as reported in other mapping populations.

Specific Variation in Shoot Growth and Root Traits Under Waterlogging Conditions of The Seedlings of Tribe Triticeae including Mizutakamoji (Agropyron Humidum)

“…Furthermore, recently in Japan, wheat and barley, in spite of their poor adaptability to waterlogging, are cultivated in drained rice paddy field to reduce over production of rice. This was similar to the report on maize by Mano et al (2005a). Increasing waterlogging tolerance of wheat and barley is an important target to increase and stabilize cereal production in Asia.…”

QTL mapping of root angle in F₂ populations from maize ‘B73’ × teosinte ‘<i>Zea luxurians</i>’

“…Although repeatability of Experiment 1 is relatively high, the observed QTLs found in Experiment 2 do not explain a large portion of the variance of the F 2 populations (from 0.123 to 0.396, largely to heterozygosity in Z. luxurians. Using a maize F 2 population of a cross between 'B64' and 'Na4', QTLs controlling adventitious root formation at the soil surface (surface rooting) during flooding were located on chromosomes 3, 7 and 8 (Mano et al 2005d). When compared, overlap was found between the QTL for root angle (Qra2nd3rd7.04) and a QTL for surface root on chromosome 7 (bin7.04-5) of maize inbred line Na4.…”

“…Evaluation regarding the expression of QTL Qra2nd3rd7.04 under flooded conditions will be implemented to confirm the effect of the marker-assisted introgressed QTL on flooding tolerance. We have previously identified QTLs controlling surface root growth during flooding on several chromosome regions in teosinte and maize (Mano et al 2005b, Mano et al 2005d). These QTLs can be classified into morphologically related QTLs (e.g.…”

Maize Production in a Changing Climate

“…At later growth stages, some genotypes have the ability to produce adventitious roots with aerenchyma formation in the cortical region, thereby increasing the ability to tolerate excess water within the rhizosphere (Rathore et al, 1998;Zaidi, 2003). Under extended waterlogging (>3 days) formation of lysigenous aerenchyma in the cortical region of roots and brace root development on above ground nodes has been observed in waterlogging tolerant maize genotypes (Rathore et al, 1998;Singh 2001, 2002;Zaidi et al, 2003;Mano et al, 2005Mano et al, , 2007. In maize, production of adventitious roots with aerenchyma is not a constitutive but an adaptive trait, particularly under waterlogging conditions.…”

“…Moderate effect QTLs associated with shoot and root dry weight, total dry weight, plant height, and a coefficient of tolerance for water tolerance were identified across experiments on chromosomes 4 and 9. Mano et al, (2005) developed an F 2 mapping population between a maize inbred line (B64) and teosinte (Z. mays ssp. Huehuetenangensis).…”