Somaclonal variation in Asparagus officinalis plants regenerated by organogenesis from long-term callus cultures

Abstract

Somaclonal variation in plants regenerated by organogenesis from long-term cultured calluses of two diploid staminate genotypes of Asparagus officinalis cv. Argenteuil was characterized by plant phenotype, ploidy, meiotic behavior, pollen viability, fruit and seed set, and AFLP profiles. Phenotypic deviations from the donors were detected in foliage color, flower size, and cladode and flower morphology. Ploidy changes were observed in 37.8% of the 37 regenerants studied. Meiotic alterations in 12 out of 21 regenerants included laggards, dicentric bridges, micronuclei, restitution nuclei and polyads. Of the 408 AFLP markers screened in 43 regenerants and the donors, 2.94% showed polymorphism. High pollen viability was observed in the 22 regenerants analyzed. All crosses between one pistillate plant and 35 regenerants, as well as the controls, produced fruits and seeds; however, no plump seeds resulted in 35.3% of the crosses with regenerants, and no seeds germinated in 12.5% of those with apparently normal seeds. Fruit and seed set was similar in crosses with diploid regenerants with normal meiosis and the controls but was lower in crosses with diploid and polyploid regenerants with abnormal meiosis. Our results show that the regenerated plants exhibited conspicuous somaclonal variation that could be eventually exploited for in vitro selection systems.

Analysis of genetic stability of in vitro propagated potato microtubers using DNA markers

“…Application of axillary branches and somatic embryogenesis are better methods for generation of genetically stable clones. However, organogenic differentiation is very prone to somatic variation (Pontaroli and Camadro 2005). Our results demonstrated that since, there were no variations observed among the in vitro conservation media T1, T2 and T3, the most commonly used T2 was considered ideal for in vitro conservation of potato microtubers to generate true-totype plants.…”

Somaclonal variation in ‘Red Flash’ caladium: morphological, cytological and molecular characterization

“…The objectives of this study were to (1) assess the type and frequency of somaclonal variation in a caladium cultivar that was widely grown and phenotypically stable, (2) evaluate the effect of two types of explant and auxin on somaclonal variation, and (3) characterize the nuclear DNA content, chromosome number, and molecular marker banding pattern of the obtained somaclonal variants. Experimental data on these aspects of somaclonal variation had been scarce in the aroid family (Raimondi et al 2001;Pontaroli and Camadro 2005). Information gained from this study might also be valuable to other aroids and ornamental plants.…”

Chromosome variations in regenerants of Arabidopsis thaliana derived from 2- and 6-week-old callus detected using flow cytometry and FISH analyses

“…There are several factors which can influence the ploidy level of the regenerants. Regeneration via organogenesis was said to induce greater variation than in case of somatic embryogenesis (Pontaroli and Camadro 2005). Gaj (2001) showed that all A. thaliana regenerants obtained through somatic embryogenesis were diploids.…”