Collections of deletion mutants are important tools for functional genomics in crops. In order to establish an efficient physical gamma-ray-based mutagenesis protocol and estimate the frequency of induced chromosome deletion events in apple, we mutagenized a total of 338 leaves of the apple cultivar 'Golden Delicious' with a range of irradiation doses (from 0 to 30 Gy). After in vitro culture and regeneration, a total of 248 plantlets were genotyped by a custom-made 384 SNP-based array suited to identify homozygous regions, corresponding to chromosome deletions produced by the irradiation and/or the in vitro culture treatments. With this approach, we identified nine multi-SNP chromosome deletions corresponding to 3.7 % of all regenerated plantlets and ranging from one to 44 cM (0.1-20.2 Mb). Chromosome deletions were also observed at mildly, not significantly lower frequency in plantlets regenerated from non-irradiated leaves. Our results confirm the possibility to generate apple plants with sizeable deletions of known dimension and location, opening the way to creating a collection of deletions spanning the apple genome useful for functional genomics. The high frequency of deletions apparently caused by somaclonal variation deserves further investigation.
High frequency of chromosome deletions in regenerated and mutagenized apple (Malus x domestica Borkh.) seedlings
Predieri S;Fuochi P;
2015
Abstract
Collections of deletion mutants are important tools for functional genomics in crops. In order to establish an efficient physical gamma-ray-based mutagenesis protocol and estimate the frequency of induced chromosome deletion events in apple, we mutagenized a total of 338 leaves of the apple cultivar 'Golden Delicious' with a range of irradiation doses (from 0 to 30 Gy). After in vitro culture and regeneration, a total of 248 plantlets were genotyped by a custom-made 384 SNP-based array suited to identify homozygous regions, corresponding to chromosome deletions produced by the irradiation and/or the in vitro culture treatments. With this approach, we identified nine multi-SNP chromosome deletions corresponding to 3.7 % of all regenerated plantlets and ranging from one to 44 cM (0.1-20.2 Mb). Chromosome deletions were also observed at mildly, not significantly lower frequency in plantlets regenerated from non-irradiated leaves. Our results confirm the possibility to generate apple plants with sizeable deletions of known dimension and location, opening the way to creating a collection of deletions spanning the apple genome useful for functional genomics. The high frequency of deletions apparently caused by somaclonal variation deserves further investigation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
