Exploration of maize landraces of Eastern Himalayan region for
waterlogging tolerance at seedling and flowering stages through
phenotyping of Root System Architecture
Abstract
A field experiment was conducted to phenotype the root traits and screen
35 local maize landraces of Eastern Himalayan region for waterlogging
tolerance at seedling and flowering stage. Microcosm screening was done
at seedling stage (6-8 leaf stage) with pots maintained with flooded
water to a level of 4-5 cm above the soil surface for 15 days
continuously. Artificial flooding stress to a depth of 20-25 cm above
the soil surface for 10 days continuously was induced at the time of
flowering in the field. This was majorly performed to trace the
plasticity of root architecture through phenotyping. The evaluation and
selection of different maize landraces for waterlogging stress at
seedling stage was established through shovelomics with the apparent
calculation of response coefficient (RC) as rightful/ surrogate
indication of phenotypic plasticity and waterlogging tolerance
coefficient (WTC). For assessing the field performance, each stress
responsive trait viz., BW, BO, BA1, BA2, BB, CN, CA and CB were assigned
scoring values from one to nine visually which ideally serve as
screening measure for waterlogging tolerance. The results revealed that
genotypes RCM-44-19, RCM-16-19, RCM-39-19, RCM-42-19, RCM-15-19,
RCM-51-19, RCM-9-19, RCM-45-19, RCM-32-19, RCM-43-19, RCM-10-19,
RCM-49-19, RCM-12-19 and RCM-26-19 were identified as WL tolerant at
seedling stage and some genotypes like RCM-12-19, RCM-32-19, RCM-16-19
and RCM-23-19 showed vigorous root growth and branching after
waterlogged treatment at flowering stage. The genotypes like RCM-12-19,
RCM-32-19 and RCM-16-19 were designated as flooding stress tolerant at
both the crop growth stages which could be of appropriate utility for
the upcoming maize breeding program under excess moisture-prone
environments of North East hilly regions after systematic validation
through advance molecular tools.