Articles

Assessing drought tolerance using PEG- 6000 and molecular screening by SSR markers in maize (Zea mays L.) hybrids


Abstract


Maize is a versatile crop, widely grown across the world but its yield potential is severely affected by drought
stress due to frequent monsoon failure. Identification of tolerant maize hybrids at seedling stage itself could be
a better option than evaluation at maturity stage. Hence, experiments were conducted to screen maize hybrids
under induced PEG stress and also with molecular marker analysis. A laboratory experiment was conducted with
twenty one hybrids and the experiment was laid out under completely randomized design (CRD) with two replications.
PEG-6000 treatment was applied in three concentrations (0, 10 and 20%) which induced osmotic stress
levels of 0, -3 and -6 bars respectively. The experimental results revealed that there was significant reduction in
seedling characteristics viz., germination percentage, shoot length, seminal root length, fresh weight, dry weight,
seed vigour index I and seed vigour index II with increase in PEG concentration. The per se performance revealed
that the hybrids AUK-30 and AUMH-8855 were drought tolerant. Promptness index and germination stress
tolerance index were found as reliable indicators to screen drought tolerant hybrids at seedling stage. Fourteen
drought linked SSR markers were used to characterize the hybrids of which the primer umc1962 was highly informative
in identifying tolerant hybrids as it formed distinct bands. The earlier identified tolerant hybrids showed
highest genetic identity values in Nei’s matrix. Hence, the hybrids AUK-30 and AUMH-8855 resulted drought
tolerant both phenotypically and genotypically

Keywords

Drought, PEG-6000, Osmotic stress, SSR marker, Nei’s matrix, Genetic identity

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Maydica - A journal devoted to maize and allied species

ISSN: 2279-8013