Abstract: |
Drought is a major abiotic stress that greatly affects canola growth, production, and quality.
Moreover, water scarcity is projected to be more severe and frequent as a result of climate change, in
particular in arid environments. Thereupon, developing drought-tolerant and high-yielding canola
genotypes has become more critical to sustaining its production and ensuring global food security
with the continuing population growth. In the present study, ten canola genotypes comprising six
developed tissue-cultured canola genotypes, two exotic genotypes, and two commercial cultivars
were evaluated under four irrigation regimes. The applied irrigation regimes were well-watered
(100% crop evapotranspiration, ETc), mild drought (80% ETc), moderate drought (60% ETc), and
severe drought (40% ETc) conditions. Drought-stress treatments (80, 60, and 40% ETc) gradually
reduced the chlorophyll content, relative water content, flowering time, days to maturity, plant height,
number of pods, number of branches, seed yield, and oil percentage, and increased proline, phenolic,
anthocyanin, and glycine betaine contents. The evaluated genotypes exhibited varied responses to
drought-stress conditions. The developed tissue-cultured genotypes T2, T3, and T1, as well as exotic
genotype Torpe, possessed the highest performance in all evaluated parameters and surpassed the
other tested genotypes under water-deficit conditions. Overall, our findings elicited the superiority
of certain newly developed tissue-cultured genotypes and exotic ones compared with commercial
cultivars, which could be exploited in canola breeding under water-deficit conditions.
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