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Quantitative description of the effect of stratification on dormancy release of grape seeds in response to various temperatures and water contents.

Wang WQ, Song SQ, Li SH, Gan YY, Wu JH, Cheng HY - J. Exp. Bot. (2009)

Bottom Line: The effect of stratification on dormancy release of grape seeds crossing from the sub- to the supraoptimal range of temperatures and water contents was analysed by modified threshold models.The thermal time approaches effectively quantified dormancy release only at suboptimal temperature, but a quantitative method to integrate the occurrence of dormancy release and induction at the same time could describe it well at either sub- or supraoptimal temperatures.Dormancy release in grape seeds can occur across a very wide range of conditions, which has important implications for their ability to adapt to a changeable environment in the wild.

View Article: PubMed Central - PubMed

Affiliation: Institute of Botany, the Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The effect of stratification on dormancy release of grape seeds crossing from the sub- to the supraoptimal range of temperatures and water contents was analysed by modified threshold models. The stratification impacted on dormancy release in three different ways: (i) dormancy was consistently released with prolonged stratification time when stratified at temperatures of <15 degrees C; (ii) at 15 degrees C and 20 degrees C, the stratification effect initially increased, and then decreased with extended time; and (iii) stratification at 25 degrees C only reduced germinable seeds. These behaviours indicated that stratification could not only release primary dormancy but also induce secondary dormancy in grape seed. The rate of dormancy release changed linearly in two phases, while induction increased exponentially with increasing temperature. The thermal time approaches effectively quantified dormancy release only at suboptimal temperature, but a quantitative method to integrate the occurrence of dormancy release and induction at the same time could describe it well at either sub- or supraoptimal temperatures. The regression with the percentage of germinable seeds versus stratification temperature or water content within both the sub- and supraoptimal range revealed how the optimal temperature (T(so)) and water content (W(so)) for stratification changed. The T(so) moved from 10.6 degrees C to 5.3 degrees C with prolonged time, while W(so) declined from >0.40 g H2O g DW(-1) at 5 degrees C to approximately 0.23 g H2O g DW(-1) at 30 degrees C. Dormancy release in grape seeds can occur across a very wide range of conditions, which has important implications for their ability to adapt to a changeable environment in the wild.

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Change of rate of dormancy release and induction. From the regression between the stratification time and germination of seeds after stratification (Fig. 2), the estimated rates of dormancy release (filled circles) and induction (filled squares) were plotted and regressed versus temperature of stratification. The rate of dormancy release showed a two-phase linear change, while induction exhibited an exponential increase with temperature. The intercepts of the two-phase linear line on the temperature axis were –10.9 °C and 24.5 °C.
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fig3: Change of rate of dormancy release and induction. From the regression between the stratification time and germination of seeds after stratification (Fig. 2), the estimated rates of dormancy release (filled circles) and induction (filled squares) were plotted and regressed versus temperature of stratification. The rate of dormancy release showed a two-phase linear change, while induction exhibited an exponential increase with temperature. The intercepts of the two-phase linear line on the temperature axis were –10.9 °C and 24.5 °C.

Mentions: From the regression of the percentage of germinable seeds versus stratification time (Fig. 2), the rate of dormancy release and induction were obtained. The rate of dormancy release linearly increased with increasing temperature from 0 °C to 10°C as:(10)and then decreased with increasing temperature from 10 °C to 25 °C (Fig. 3):(11)where rsl and rsu are the rate of dormancy release over a range of the corresponding temperatures, respectively. The inflexion of the regression lines of the rate of dormancy release defined the optimal temperature for dormancy release (Tso), ∼9.8 °C (Fig. 3). From Equations 10 and 11, Tsb and STc at sub- (Ts ≤9.8 °C) and supra- (Ts ≥9.8 °C) optimal temperature were calculated as –10.9 °Cd and 107.5 °Cd, respectively. At this time, the change in the percentage of germinable seeds with Stt (Fig. 4A) or Tsc (Fig. 4B) could be analysed via the thermal time approaches (Equations 5–8). At suboptimal temperatures, the increase in the percentage of germinable seeds with Stt followed one regression line when seed were stratified at 0–6 °C (Fig. 4A; F6,72=0.84; Tabulate F6,72=2.23, P=0.55), while at supraoptimal temperatures the change in the percentage of germinable seeds with Tsc varied greatly (Fig. 4B). On the other hand, if Tsc was assumed to be constant but STc was assumed to follow a log-normal distribution (Equation 6), the regression lines had a similarly significant difference among the supraoptimal temperatures (data not shown).


Quantitative description of the effect of stratification on dormancy release of grape seeds in response to various temperatures and water contents.

Wang WQ, Song SQ, Li SH, Gan YY, Wu JH, Cheng HY - J. Exp. Bot. (2009)

Change of rate of dormancy release and induction. From the regression between the stratification time and germination of seeds after stratification (Fig. 2), the estimated rates of dormancy release (filled circles) and induction (filled squares) were plotted and regressed versus temperature of stratification. The rate of dormancy release showed a two-phase linear change, while induction exhibited an exponential increase with temperature. The intercepts of the two-phase linear line on the temperature axis were –10.9 °C and 24.5 °C.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2724692&req=5

fig3: Change of rate of dormancy release and induction. From the regression between the stratification time and germination of seeds after stratification (Fig. 2), the estimated rates of dormancy release (filled circles) and induction (filled squares) were plotted and regressed versus temperature of stratification. The rate of dormancy release showed a two-phase linear change, while induction exhibited an exponential increase with temperature. The intercepts of the two-phase linear line on the temperature axis were –10.9 °C and 24.5 °C.
Mentions: From the regression of the percentage of germinable seeds versus stratification time (Fig. 2), the rate of dormancy release and induction were obtained. The rate of dormancy release linearly increased with increasing temperature from 0 °C to 10°C as:(10)and then decreased with increasing temperature from 10 °C to 25 °C (Fig. 3):(11)where rsl and rsu are the rate of dormancy release over a range of the corresponding temperatures, respectively. The inflexion of the regression lines of the rate of dormancy release defined the optimal temperature for dormancy release (Tso), ∼9.8 °C (Fig. 3). From Equations 10 and 11, Tsb and STc at sub- (Ts ≤9.8 °C) and supra- (Ts ≥9.8 °C) optimal temperature were calculated as –10.9 °Cd and 107.5 °Cd, respectively. At this time, the change in the percentage of germinable seeds with Stt (Fig. 4A) or Tsc (Fig. 4B) could be analysed via the thermal time approaches (Equations 5–8). At suboptimal temperatures, the increase in the percentage of germinable seeds with Stt followed one regression line when seed were stratified at 0–6 °C (Fig. 4A; F6,72=0.84; Tabulate F6,72=2.23, P=0.55), while at supraoptimal temperatures the change in the percentage of germinable seeds with Tsc varied greatly (Fig. 4B). On the other hand, if Tsc was assumed to be constant but STc was assumed to follow a log-normal distribution (Equation 6), the regression lines had a similarly significant difference among the supraoptimal temperatures (data not shown).

Bottom Line: The effect of stratification on dormancy release of grape seeds crossing from the sub- to the supraoptimal range of temperatures and water contents was analysed by modified threshold models.The thermal time approaches effectively quantified dormancy release only at suboptimal temperature, but a quantitative method to integrate the occurrence of dormancy release and induction at the same time could describe it well at either sub- or supraoptimal temperatures.Dormancy release in grape seeds can occur across a very wide range of conditions, which has important implications for their ability to adapt to a changeable environment in the wild.

View Article: PubMed Central - PubMed

Affiliation: Institute of Botany, the Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The effect of stratification on dormancy release of grape seeds crossing from the sub- to the supraoptimal range of temperatures and water contents was analysed by modified threshold models. The stratification impacted on dormancy release in three different ways: (i) dormancy was consistently released with prolonged stratification time when stratified at temperatures of <15 degrees C; (ii) at 15 degrees C and 20 degrees C, the stratification effect initially increased, and then decreased with extended time; and (iii) stratification at 25 degrees C only reduced germinable seeds. These behaviours indicated that stratification could not only release primary dormancy but also induce secondary dormancy in grape seed. The rate of dormancy release changed linearly in two phases, while induction increased exponentially with increasing temperature. The thermal time approaches effectively quantified dormancy release only at suboptimal temperature, but a quantitative method to integrate the occurrence of dormancy release and induction at the same time could describe it well at either sub- or supraoptimal temperatures. The regression with the percentage of germinable seeds versus stratification temperature or water content within both the sub- and supraoptimal range revealed how the optimal temperature (T(so)) and water content (W(so)) for stratification changed. The T(so) moved from 10.6 degrees C to 5.3 degrees C with prolonged time, while W(so) declined from >0.40 g H2O g DW(-1) at 5 degrees C to approximately 0.23 g H2O g DW(-1) at 30 degrees C. Dormancy release in grape seeds can occur across a very wide range of conditions, which has important implications for their ability to adapt to a changeable environment in the wild.

Show MeSH
Related in: MedlinePlus