TITLE:
Adaptability and recovery capability of two maize inbred-line foundation genotypes, following treatment with progressive water-deficit stress and stress recovery
AUTHORS:
Xianwei Fan, Guiyuan Huang, Liujun Zhang, Tao Deng, Youzhi Li
KEYWORDS:
Maize Inbred Lines; Morphological Response; Gas Exchange; Chlorophyll Fluorescence; Water-Deficit Stress; Recovery
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.8,
August
9,
2013
ABSTRACT: Two maize inbred
lines, the foundation genotype Y478 and its derived line Z58, are widely used
to breed novel maize cultivars in China, but little is known about which traits
confer Z58 with superior drought tolerance and yield. In the present study, responses
in growth traits, photosynthetic parameters, chlorophyll fluorescence and
leaf micromorphological characteristics were evaluated in Y478 and Z58
subjected to water-deficit stress induced by PEG 6000. The derived line Z58 showed
greater drought tolerance than Y478, which was associated with higher leaf relative
water content (RWC), root efficiency, and strong growth recovery. Z58 showed a
higher stomatal density and stomatal area under the non-stressed condition; in
these traits, both genotypes showed a similar decreasing trend with increased
severity of water-deficit stress. In addition, the stomatal size of Y478
declined significantly. These
micromorphological differences between the two lines were consistent
with changes in physiological parameters, which may contribute to the enhanced
capability for growth recovery in Z58. A non-linear response of Fv/Fm to leaf RWC was observed, and Fv/Fm decreased rapidly with a further gradual decline of leaf RWC. The relationship
between other chlorophyll fluorescence parameters (photochemical quenching
and electron transport rate) and RWC is also discussed.