High Frequency Adventitious Shoot Formation and Plant Regeneration in Leaf Explant Cultures of Ixeris sonchifolia Hance, a Newly Proposed Model Plant for Organogenesis

Leaf explants of Ixeris sonchifolia produced adventitious shoots at a frequency of 100% when cultured on MS medium supplemented with combinations of various concentrations of 6-benzyladenine (BA) (0.44, 4.44, or 8.87 ${\mu}M$) and 0.54 ${\mu}M$ NAA, or MS medium supplemented with 22.19 ${\mu}M$ BA and 2.69 ${\mu}M\;\alpha$-naphthaleneacetic acid (NAA) after four weeks of culture. Each explants (approximately $3{\times}6mm$) produced greater than 70 shoots at a combination of 0.44 ${\mu}M$ BA and 0.54 ${\mu}M$ NAA. Leaf explants produced shoots at a frequency of greater than 80% even at as low as 0.13 ${\mu}M$ BA as the sole growth regulator. Upon transfer to one-third strength MS with 0.54 ${\mu}M$ NAA, excised adventitious shoots were rooted at a frequency of 100%. Regenerated plantlets were transplanted to potting soil and grown to maturity in a greenhouse. The competence of I. sonchifolia for plant regeneration via organogenesis appears to be greater than the competence of tobacco, currently the best model plant for organogenesis.