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Winter cold-tolerance thresholds in field-grown Miscanthus hybrid rhizomes.

Peixoto Mde M, Friesen PC, Sage RF - J. Exp. Bot. (2015)

Bottom Line: Two artificial freezing protocols were tested: one lowered the temperature continuously by 1°C h(-1) to the treatment temperature and another lowered the temperature in stages of 24h each to the treatment temperature.The results demonstrated that rhizomes from diploid Miscanthus lines have superior cold tolerance that could be exploited to improve performance in more productive polyploid lines.With expected levels of soil insulation, low winter air temperatures should not harm rhizomes of tolerant diploid genotypes of Miscanthus in temperate to sub-boreal climates (up to 60°N); however, the observed winter cold in sub-boreal climates could harm rhizomes of existing polyploid varieties of Miscanthus and thus reduce stand performance.

View Article: PubMed Central - PubMed

Affiliation: University of Toronto, Department of Ecology and Evolutionary Biology, 25 Willcocks Street, Toronto, Ontario, Canada M5S3B2.

No MeSH data available.


Related in: MedlinePlus

Survivability of Miscanthus rhizomes as a function of temperature in the staged-cooling rate experiment. (A) M115; (B) M147; (C) M1; (D) M119. Symbols represent means±SE (n=6) and lines represent the predicted response using a logistic regression fitted to the data. Filled diamonds, January 2011; open circles, February 2011. One regression line was drawn for both collection times because there was no difference between them (P=0.479). The difference in survivability between the Miscanthus genotypes was significant (P<0.001) and a post-hoc Tukey test differentiated the diploids from M1 and M119 (Pz<0.001). Differences between diploids (Pz=0.219) or between M1 and M119 (Pz=0.993) were not significant.
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Figure 6: Survivability of Miscanthus rhizomes as a function of temperature in the staged-cooling rate experiment. (A) M115; (B) M147; (C) M1; (D) M119. Symbols represent means±SE (n=6) and lines represent the predicted response using a logistic regression fitted to the data. Filled diamonds, January 2011; open circles, February 2011. One regression line was drawn for both collection times because there was no difference between them (P=0.479). The difference in survivability between the Miscanthus genotypes was significant (P<0.001) and a post-hoc Tukey test differentiated the diploids from M1 and M119 (Pz<0.001). Differences between diploids (Pz=0.219) or between M1 and M119 (Pz=0.993) were not significant.

Mentions: When rhizomes were frozen gradually in a staged manner, rhizome survivability did not differ between the January 2011 and February 2011 collections but did differ among genotypes (Fig. 6). M115 and M147 had lower LT50 values (–14.4 and –12.6 °C, respectively), with no rhizome surviving below –15 °C (Fig. 6A, B). The triploid (M1) and tetraploid (M119) genotypes had similar survival patterns to the triploid and tetraploid genotypes tested in the continuous-cooling experiment, and were considerably less cold tolerant than the diploids. Their LT50 values were –6.6 and –6.3 °C, respectively (Fig. 6C, D). At –10 °C, no rhizome of the M1 and M119 genotypes survived in January 2011, and just one out of six rhizomes survived in the February 2011 sampling. Below –10 °C, no rhizome from M1 and M119 survived.


Winter cold-tolerance thresholds in field-grown Miscanthus hybrid rhizomes.

Peixoto Mde M, Friesen PC, Sage RF - J. Exp. Bot. (2015)

Survivability of Miscanthus rhizomes as a function of temperature in the staged-cooling rate experiment. (A) M115; (B) M147; (C) M1; (D) M119. Symbols represent means±SE (n=6) and lines represent the predicted response using a logistic regression fitted to the data. Filled diamonds, January 2011; open circles, February 2011. One regression line was drawn for both collection times because there was no difference between them (P=0.479). The difference in survivability between the Miscanthus genotypes was significant (P<0.001) and a post-hoc Tukey test differentiated the diploids from M1 and M119 (Pz<0.001). Differences between diploids (Pz=0.219) or between M1 and M119 (Pz=0.993) were not significant.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4493781&req=5

Figure 6: Survivability of Miscanthus rhizomes as a function of temperature in the staged-cooling rate experiment. (A) M115; (B) M147; (C) M1; (D) M119. Symbols represent means±SE (n=6) and lines represent the predicted response using a logistic regression fitted to the data. Filled diamonds, January 2011; open circles, February 2011. One regression line was drawn for both collection times because there was no difference between them (P=0.479). The difference in survivability between the Miscanthus genotypes was significant (P<0.001) and a post-hoc Tukey test differentiated the diploids from M1 and M119 (Pz<0.001). Differences between diploids (Pz=0.219) or between M1 and M119 (Pz=0.993) were not significant.
Mentions: When rhizomes were frozen gradually in a staged manner, rhizome survivability did not differ between the January 2011 and February 2011 collections but did differ among genotypes (Fig. 6). M115 and M147 had lower LT50 values (–14.4 and –12.6 °C, respectively), with no rhizome surviving below –15 °C (Fig. 6A, B). The triploid (M1) and tetraploid (M119) genotypes had similar survival patterns to the triploid and tetraploid genotypes tested in the continuous-cooling experiment, and were considerably less cold tolerant than the diploids. Their LT50 values were –6.6 and –6.3 °C, respectively (Fig. 6C, D). At –10 °C, no rhizome of the M1 and M119 genotypes survived in January 2011, and just one out of six rhizomes survived in the February 2011 sampling. Below –10 °C, no rhizome from M1 and M119 survived.

Bottom Line: Two artificial freezing protocols were tested: one lowered the temperature continuously by 1°C h(-1) to the treatment temperature and another lowered the temperature in stages of 24h each to the treatment temperature.The results demonstrated that rhizomes from diploid Miscanthus lines have superior cold tolerance that could be exploited to improve performance in more productive polyploid lines.With expected levels of soil insulation, low winter air temperatures should not harm rhizomes of tolerant diploid genotypes of Miscanthus in temperate to sub-boreal climates (up to 60°N); however, the observed winter cold in sub-boreal climates could harm rhizomes of existing polyploid varieties of Miscanthus and thus reduce stand performance.

View Article: PubMed Central - PubMed

Affiliation: University of Toronto, Department of Ecology and Evolutionary Biology, 25 Willcocks Street, Toronto, Ontario, Canada M5S3B2.

No MeSH data available.


Related in: MedlinePlus