In vitro regeneration of wild pear (Pyrus pyraster Burgsd) clones tolerant to Fe-chlorosis and somaclonal variation analysis by RAPD markers.
An in vitro adventitious regeneration system under selective pressure was established in Pyrus pyraster Burgsd to obtain somaclones with higher adaptability to calcareous soils. P. pyraster is important species, both for its relative closeness to cultivated pear and for reforestation of marginal farmland and for the production of timber. Shoot regeneration was induced from leaves and vegetative apices of in vitro-grown shoots on a modified LP medium supplemented with naphtaleneacetic acid (1.07 microM) and benziladenine (BA, 8.9 microM). After 30 days, explants were transferred to an expression medium consisting of the same basal medium with only BA present. Selective treatments utilized MS medium with Fe-EDTA replaced by equimolar amount of FeSO4 with either KHCO(3) or NaHCO(3). Through the selection process 11 putatively tolerant lines were obtained from vegetative shoot apices. RAPD analysis was performed on these lines to allow comparison to the mother clone. A total of seven 10-mer primers were used to amplify all the genotypes and 74 scorable fragments were produced. These were analysed using the Dice similarity index, showing genetic variability among the 11 regenerated clones and between them and the mother clone.
Palombi
Maria Antonietta
MA
CRA-Istituto Sperimentale per la Frutticoltura, Via di Fioranello 52, Rome, Italy. ma.palombi@propag.org
Lombardo
Beatrice
B
Caboni
Emilia
E
D000222:Adaptation, Physiological / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D018744:DNA, Plant / Q000032:analysis / Q000235:genetics; D014644:Genetic Variation; D007501:Iron / Q000494:pharmacology*; D009280:Naphthaleneacetic Acids / Q000494:pharmacology; D018520:Plant Shoots / Q000235:genetics / Q000502:physiology; D031989:Pyrus / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D019105:Random Amplified Polymorphic DNA Technique; D012038:Regeneration; D046509:Tissue Culture Techniques
D003470:Culture Media; D018744:DNA, Plant; D009280:Naphthaleneacetic Acids; D007501:Iron