Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0025-6153

Maize (Zea mays L.) grown in droughtprone environments often face a multitude of abiotic stresses like desiccation, aluminum-toxicity and heat. The aim of the present study was to ascertain differences in root morphology in response to desiccation, heat and aluminum stress in tropical maize inbred lines used for research towards drought tolerance at flowering by CIMMYT; K64R, SC-Malawi and Ac7729TZSRW are susceptible, while H16, CML444 and Ac7643 are tolerant. Plants were grown on germination blotter in growth pouches until the V2 stage. The lengths of axile and lateral roots were measured non-destructively at 4, 6, 8 and 10 days after germination by scanning with an A4 flatbed scanner followed by digital image analysis. All lines were subjected to aluminum (AlCl3) in the range from 0 to 15 mmol at a pH of 4.3, high temperature of 37°C, and desiccation stress induced by Polyethylene glycol 8000 (PEG) concentrations of 15% and 20%. Elongation of lateral and axile roots were reduced in response to desiccation, heat and aluminum stress. H16 was most tolerant to aluminum; H16, CML444 and SC-Malawi were less severely affected by high temperatures. H16 and CML444 were not tolerant to desiccation in the present study, indicating that their yielding ability observed under drought is rather related to drought avoidance. This finding is corroborated by the finding that under desiccation stress growth of seminal axile roots was reduced in favor of the primary axile root. Under field conditions this pattern will allow the plant to avoid desiccation by reaching greater depths and tap water potentially available in deeper soil strata.

Global Maize Program

English

No CIMMYT affiliation

Carelia Juarez

INT3300

Reprints Collection