Germination stage
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Vigor of germination
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Vigor of germination (%) = Number of germinated grains/Number of total grains × 100
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14°C/7-17 d
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-
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(Han et al. [2006])
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Seedling survival rate
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Seedling survival rate (%) = Surviving seedlings/Sprouting seeds × 100, determined when shoots are about 5 mm long.
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2°C/3 d
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20°C/7 d
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(Zhou et al. [2012])
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Seedling stage
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Fresh weight (FW)
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Changes in FW of plants after cold treatment can be used as an indicator of cold damage.
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10°C/1-48°h
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-
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(Bonnecarrère et al. [2011])
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Survival rate
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Survival rate (%) after cold treatment is calculated as the Number of surviving plants/Total number plants treated × 100
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4°C/6 d
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26°C/6 d
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(Zhang et al. [2011b])
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Leaf emergence
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New leaf emergence demonstrates maintained vigor and increased growth.
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4°C/7 d
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25°C/10 d
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(Xie et al. [2012])
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Seedling growth
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1 = dark green seedlings, 3 = light green seedlings, 5 = yellow seedlings, 7 = brown seedlings, 9 = seedlings dead.
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9°C/8-14 d
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-
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(Kim and Tai [2011]; IRRI [2002]; Andaya and Tai [2006])
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Leaf growth
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A score of 1-3 (tolerant, all leaves normal, no apparent visual injury), or 4-9 (susceptible, all leaves wilted, seedlings apparently dead).
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10°C/7 d
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25°C/7 d
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(Suh et al. [2012])
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Metabolic assessments
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Metabolites include EL, proline, MDA, and AsA, and GSH.
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9°C/1-14 d
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-
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(Tian et al. [2011]; Zhang et al. [2011a]; Kim and Tai [2011]; Yang et al. [2012])
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Enzyme activities
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Enzymes include POD, SOD, and CAT, and APX.
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4°C/0-4 d
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25°C/7 d
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(Bonnecarrère et al. [2011]; Huang et al. [2009]; Sato et al. [2001])
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Reproductive stage
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Spikelet fertility (CGC)
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Spikelet fertility is calculated as the ratio of filled grains to the total number of florets, basing on cold greenhouse cultivation.
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12°C/6 d
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Until maturation
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(Sato et al. [2011])
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Spikelet fertility (CDWI)
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Spikelet fertility is calculated as the same as spikelet fertility (CGC), but the cold treatment is based on cold deep-water irrigation.
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18-19°C/~60 d
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-
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(Shirasawa et al. [2012])
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