Articles
MOLECULAR AND PHENOTYPIC CHARACTERIZATION OF SOMACLONAL VARIATION IN DATE PALM OFF-TYPES ORIGINATED FROM TISSUE CULTURE
Article number
738_50
Pages
417 – 423
Language
English
Abstract
Propagation of date palms using tissue culture techniques is very advantageous.
However, among the normal trees, many off-type trees are generated.
These abnormal phenotypes include variegation, low level fruit setting and dwarfism.
The last two tend to occur in mass numbers mainly in plantlets of specific tissue culture laboratories.
While some off-types are easily detected in young plantlets, others are commonly detected in the field only years after planting.
Therefore, both preventing the generation and developing methods for early detection of these off-types are necessary.
The present study applies molecular techniques to characterize the abnormal phenotypes.
We applied Amplified Fragment Length Polymorphism (AFLP) to characterize the three common date palm off-type phenotypes.
In the variegated trees multiple mutations seem to occur.
In contrast, only relatively few mutations were detected among the low level fruit setting and dwarf trees.
No single specific mutation was found to be associated with these phenotypes.
Differences in DNA-methylation patterns were found among the off-type trees.
Reduction in the overall DNA methylation level seems to be associated with the low fruit setting phenotype.
Changes in DNA methylation patterns were previously suggested to be involved in generation of somaclonal variation.
It seems that similarly, changes in DNA methylation patterns that occur during the tissue culture process may generate a developmentally altered scheme.
This may result in off-types which can only be detected long after the planting of the trees.
Specific sequence variations and/or DNA methylation assays can be useful in detecting off-type plantlets before they are planted in the field.
However, among the normal trees, many off-type trees are generated.
These abnormal phenotypes include variegation, low level fruit setting and dwarfism.
The last two tend to occur in mass numbers mainly in plantlets of specific tissue culture laboratories.
While some off-types are easily detected in young plantlets, others are commonly detected in the field only years after planting.
Therefore, both preventing the generation and developing methods for early detection of these off-types are necessary.
The present study applies molecular techniques to characterize the abnormal phenotypes.
We applied Amplified Fragment Length Polymorphism (AFLP) to characterize the three common date palm off-type phenotypes.
In the variegated trees multiple mutations seem to occur.
In contrast, only relatively few mutations were detected among the low level fruit setting and dwarf trees.
No single specific mutation was found to be associated with these phenotypes.
Differences in DNA-methylation patterns were found among the off-type trees.
Reduction in the overall DNA methylation level seems to be associated with the low fruit setting phenotype.
Changes in DNA methylation patterns were previously suggested to be involved in generation of somaclonal variation.
It seems that similarly, changes in DNA methylation patterns that occur during the tissue culture process may generate a developmentally altered scheme.
This may result in off-types which can only be detected long after the planting of the trees.
Specific sequence variations and/or DNA methylation assays can be useful in detecting off-type plantlets before they are planted in the field.
Authors
Yuval Cohen, Vyacheslav Gurevich, Raia Korchinsky, Maor Shochat, Sekar Makesh, Uri Lavi
Keywords
AFLP, DNA methylation, dwarfism, flower abnormalities, Phoenix dactylifera, somaclonal variation
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