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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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Time course of germination of grape seeds stratified at different temperatures for different time periods. Seeds were mixed with moist perlite (water content of 2 g H2O g−1 DW), and stratified at 0 (A), 3 (B), 6 (C), 10 (D), 15 (E), 20 (F), 25 (G), and 15 °C/5°C (H) for 5, 10, 15, 20, 30, and 60 d, respectively, and then germinated at 30 °C/20 °C for 30 d. All values are means ±SD, and the solid lines are the logistic regression lines.
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fig1: Time course of germination of grape seeds stratified at different temperatures for different time periods. Seeds were mixed with moist perlite (water content of 2 g H2O g−1 DW), and stratified at 0 (A), 3 (B), 6 (C), 10 (D), 15 (E), 20 (F), 25 (G), and 15 °C/5°C (H) for 5, 10, 15, 20, 30, and 60 d, respectively, and then germinated at 30 °C/20 °C for 30 d. All values are means ±SD, and the solid lines are the logistic regression lines.

Mentions: Dormancy release, quantified by the dynamics of germination, was strongly influenced by the stratification temperature and time periods (Fig. 1). After germination at 30 °C/20 °C in darkness for 30 d, germination of the control (unstratified) seeds was ∼23.3%, and the stratification treatment significantly changed the germination of seeds (Fig. 1). When stratified at 0–10 °C and 15 °C/5 °C, the dormancy of seeds was continuously released, which eventually allowed >80% of seeds to germinate (Fig. 1A–D, H). In addition, the stratification not only released the seed dormancy, but also increased germination rates with increasing stratification times at these temperatures (Fig. 1A–D, H), particularly visible at 15 °C/5 °C (Fig. 1H). Although the stratification at 15 °C for 30 d also resulted in dormancy release of 75% of seeds in the population, the stratification effect decreased when the time was prolonged to 60 d (Fig. 1E). When seeds were stratified at 20 °C, the percentage of dormancy release was ∼40% during 10 d and this decreased when the stratification time was longer than 15 d (Fig. 1F). Dormancy release could not be observed when seeds were stratified at 25 °C, and the germination decreased with increasing stratification time (Fig. 1G).


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)

Time course of germination of grape seeds stratified at different temperatures for different time periods. Seeds were mixed with moist perlite (water content of 2 g H2O g−1 DW), and stratified at 0 (A), 3 (B), 6 (C), 10 (D), 15 (E), 20 (F), 25 (G), and 15 °C/5°C (H) for 5, 10, 15, 20, 30, and 60 d, respectively, and then germinated at 30 °C/20 °C for 30 d. All values are means ±SD, and the solid lines are the logistic regression lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig1: Time course of germination of grape seeds stratified at different temperatures for different time periods. Seeds were mixed with moist perlite (water content of 2 g H2O g−1 DW), and stratified at 0 (A), 3 (B), 6 (C), 10 (D), 15 (E), 20 (F), 25 (G), and 15 °C/5°C (H) for 5, 10, 15, 20, 30, and 60 d, respectively, and then germinated at 30 °C/20 °C for 30 d. All values are means ±SD, and the solid lines are the logistic regression lines.
Mentions: Dormancy release, quantified by the dynamics of germination, was strongly influenced by the stratification temperature and time periods (Fig. 1). After germination at 30 °C/20 °C in darkness for 30 d, germination of the control (unstratified) seeds was ∼23.3%, and the stratification treatment significantly changed the germination of seeds (Fig. 1). When stratified at 0–10 °C and 15 °C/5 °C, the dormancy of seeds was continuously released, which eventually allowed >80% of seeds to germinate (Fig. 1A–D, H). In addition, the stratification not only released the seed dormancy, but also increased germination rates with increasing stratification times at these temperatures (Fig. 1A–D, H), particularly visible at 15 °C/5 °C (Fig. 1H). Although the stratification at 15 °C for 30 d also resulted in dormancy release of 75% of seeds in the population, the stratification effect decreased when the time was prolonged to 60 d (Fig. 1E). When seeds were stratified at 20 °C, the percentage of dormancy release was ∼40% during 10 d and this decreased when the stratification time was longer than 15 d (Fig. 1F). Dormancy release could not be observed when seeds were stratified at 25 °C, and the germination decreased with increasing stratification time (Fig. 1G).

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