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Cryotolerance of apple tree bud is independent of endodormancy.

Bilavcik A, Zamecnik J, Faltus M - Front Plant Sci (2015)

Bottom Line: The cryosurvival of vegetative apple buds of both cultivars correlated with their cold hardening without direct regard to their particular phase of dormancy.Both cultivars had the highest cryosurvival in December and January.The presented data were compared with our previous results from a dormancy study of in vitro apple culture.

View Article: PubMed Central - PubMed

Affiliation: Plant Physiology and Cryobiology Laboratory, Crop Research Institute Prague, Czech Republic.

ABSTRACT
Increasing interest in cryopreservation of dormant buds reveals the need for better understanding of the role of dormancy in cryotolerance. Dormancy stage and low-temperature survival of vegetative apple buds (Malus domestica Borkh.), cultivars 'Sampion' and 'Spartan', collected from orchard were evaluated during three seasons contrasting in temperature and precipitation throughout the arrested plant growth period. During each season, the cultivars differed either in the onset of the endodormancy or in the length of the endodormant period. A simple relation between endodormancy of the buds and their water content was not detected. The cryosurvival of vegetative apple buds of both cultivars correlated with their cold hardening without direct regard to their particular phase of dormancy. The period of the highest bud cryotolerance after low-temperature exposure overlapped with the endodormant period in some evaluated seasons. Both cultivars had the highest cryosurvival in December and January. The presented data were compared with our previous results from a dormancy study of in vitro apple culture. Endodormancy coincided with the period of successful cryosurvival of apple buds after liquid nitrogen exposure, but as such, it was not decisive for their survival and did not limit their successful cryopreservation.

No MeSH data available.


Related in: MedlinePlus

Apple tree plant cryotolerance and cold hardiness as a reaction to low temperature in relation to its (para-, endo-, eco-) dormancy. For comparison, the cryotolerance of ex vitro over all studied seasons was unified in time. The in vitro dormancy was added in the same range as ex vitro cryotolerance range. The dormancy and its parts were added in relation to evaluated cryotolerance range. From this expression, it is evident that the cryotolerance was not dependent on endodormancy, because, e.g., in the season of 1999/2000, the endormancy ended before the cryotolerace was established. The cryopreservation method for ex vitro dormant bud plants was two-step freezing, with pretreatment at –5°C for 2 months. The cryopreservation method for plants from in vitro was encapsulation/dehydration, without any pretreatment. The cryotolerance of ex vitro plants was determined after the immersion of buds in LN as a regrowth of new shoot from buds grafted on rootstock. The cryotolerance of in vitro plants was determined as new shoot regrowth in in vitro conditions. ∗Bilavcik et al. (2012).
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Figure 8: Apple tree plant cryotolerance and cold hardiness as a reaction to low temperature in relation to its (para-, endo-, eco-) dormancy. For comparison, the cryotolerance of ex vitro over all studied seasons was unified in time. The in vitro dormancy was added in the same range as ex vitro cryotolerance range. The dormancy and its parts were added in relation to evaluated cryotolerance range. From this expression, it is evident that the cryotolerance was not dependent on endodormancy, because, e.g., in the season of 1999/2000, the endormancy ended before the cryotolerace was established. The cryopreservation method for ex vitro dormant bud plants was two-step freezing, with pretreatment at –5°C for 2 months. The cryopreservation method for plants from in vitro was encapsulation/dehydration, without any pretreatment. The cryotolerance of ex vitro plants was determined after the immersion of buds in LN as a regrowth of new shoot from buds grafted on rootstock. The cryotolerance of in vitro plants was determined as new shoot regrowth in in vitro conditions. ∗Bilavcik et al. (2012).

Mentions: One of the conclusions of our work is that cryotolerance of dormant apple buds is not directly dependent on endodormancy. On the other hand, in comparison to our published results of in vitro apple plant dormancy and cryotolerance (Bilavcik et al., 2012), the endodormancy of in vitro plants overlapped with the maximum of cold hardiness and cryotolerance (Figure 8). This might be caused by conducting in vitro experiments at controlled conditions; we did not reach the temperature and moisture disturbances of environmental conditions as in the natural conditions in the orchard. Although there was an idea to divide the influence of low temperature on cold hardiness and endodormancy, we were not able to set the experimental conditions. That is why these physiological factors were lined together as it was published in the literature dealing with cryopreservation.


Cryotolerance of apple tree bud is independent of endodormancy.

Bilavcik A, Zamecnik J, Faltus M - Front Plant Sci (2015)

Apple tree plant cryotolerance and cold hardiness as a reaction to low temperature in relation to its (para-, endo-, eco-) dormancy. For comparison, the cryotolerance of ex vitro over all studied seasons was unified in time. The in vitro dormancy was added in the same range as ex vitro cryotolerance range. The dormancy and its parts were added in relation to evaluated cryotolerance range. From this expression, it is evident that the cryotolerance was not dependent on endodormancy, because, e.g., in the season of 1999/2000, the endormancy ended before the cryotolerace was established. The cryopreservation method for ex vitro dormant bud plants was two-step freezing, with pretreatment at –5°C for 2 months. The cryopreservation method for plants from in vitro was encapsulation/dehydration, without any pretreatment. The cryotolerance of ex vitro plants was determined after the immersion of buds in LN as a regrowth of new shoot from buds grafted on rootstock. The cryotolerance of in vitro plants was determined as new shoot regrowth in in vitro conditions. ∗Bilavcik et al. (2012).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561819&req=5

Figure 8: Apple tree plant cryotolerance and cold hardiness as a reaction to low temperature in relation to its (para-, endo-, eco-) dormancy. For comparison, the cryotolerance of ex vitro over all studied seasons was unified in time. The in vitro dormancy was added in the same range as ex vitro cryotolerance range. The dormancy and its parts were added in relation to evaluated cryotolerance range. From this expression, it is evident that the cryotolerance was not dependent on endodormancy, because, e.g., in the season of 1999/2000, the endormancy ended before the cryotolerace was established. The cryopreservation method for ex vitro dormant bud plants was two-step freezing, with pretreatment at –5°C for 2 months. The cryopreservation method for plants from in vitro was encapsulation/dehydration, without any pretreatment. The cryotolerance of ex vitro plants was determined after the immersion of buds in LN as a regrowth of new shoot from buds grafted on rootstock. The cryotolerance of in vitro plants was determined as new shoot regrowth in in vitro conditions. ∗Bilavcik et al. (2012).
Mentions: One of the conclusions of our work is that cryotolerance of dormant apple buds is not directly dependent on endodormancy. On the other hand, in comparison to our published results of in vitro apple plant dormancy and cryotolerance (Bilavcik et al., 2012), the endodormancy of in vitro plants overlapped with the maximum of cold hardiness and cryotolerance (Figure 8). This might be caused by conducting in vitro experiments at controlled conditions; we did not reach the temperature and moisture disturbances of environmental conditions as in the natural conditions in the orchard. Although there was an idea to divide the influence of low temperature on cold hardiness and endodormancy, we were not able to set the experimental conditions. That is why these physiological factors were lined together as it was published in the literature dealing with cryopreservation.

Bottom Line: The cryosurvival of vegetative apple buds of both cultivars correlated with their cold hardening without direct regard to their particular phase of dormancy.Both cultivars had the highest cryosurvival in December and January.The presented data were compared with our previous results from a dormancy study of in vitro apple culture.

View Article: PubMed Central - PubMed

Affiliation: Plant Physiology and Cryobiology Laboratory, Crop Research Institute Prague, Czech Republic.

ABSTRACT
Increasing interest in cryopreservation of dormant buds reveals the need for better understanding of the role of dormancy in cryotolerance. Dormancy stage and low-temperature survival of vegetative apple buds (Malus domestica Borkh.), cultivars 'Sampion' and 'Spartan', collected from orchard were evaluated during three seasons contrasting in temperature and precipitation throughout the arrested plant growth period. During each season, the cultivars differed either in the onset of the endodormancy or in the length of the endodormant period. A simple relation between endodormancy of the buds and their water content was not detected. The cryosurvival of vegetative apple buds of both cultivars correlated with their cold hardening without direct regard to their particular phase of dormancy. The period of the highest bud cryotolerance after low-temperature exposure overlapped with the endodormant period in some evaluated seasons. Both cultivars had the highest cryosurvival in December and January. The presented data were compared with our previous results from a dormancy study of in vitro apple culture. Endodormancy coincided with the period of successful cryosurvival of apple buds after liquid nitrogen exposure, but as such, it was not decisive for their survival and did not limit their successful cryopreservation.

No MeSH data available.


Related in: MedlinePlus