E Firoozabady | PubMed Health

PubMed2003

Cost-effective in vitro propagation methods for pineapple.

We have developed an efficient and cost-effective method for commercial micropropagation of Smooth Cayenne pineapple. In vitro shoots were used as starting materials, and either longitudinal sections of the shoots or leaf bases were used as the explants to regenerate shoots. When these explants were used, the axillary meristems, which usually remain quiescent during shoot multiplication, were able to form new shoots. Subsequent to the regeneration step, additional multiplication was achieved inside a 10-l Nalgene vessel with shoots immersed in liquid medium for 5-10 min/h (periodic immersion bioreactor, PIB). The shoots were then induced to form roots and transferred to soil. Using the above micropropagation method and the PIB, we produced 6,000-8,000 shoots from two initial shoots in less than 6 months. The clonal fidelity of propagated plants was tested in Costa Rican and Indonesian pineapple farms.

Ananas↗

PubMed1994

Modification of flower color in florist's chrysanthemum: production of a white-flowering variety through molecular genetics.

Chimeric chalcone synthase (CHS) constructs were prepared in both anti-sense and sense orientations, and introduced into the chrysanthemum cultivar Moneymaker, along with a T-DNA vector lacking a CHS construct. For both the anti-sense and sense constructs, the majority of the plants produced pink flowers typical of Moneymaker itself. Of 133 sense and 83 anti-sense transgenic individuals 3 of each set produced fully white or very pale pink flowers. No white-flowering transgenic plants were obtained in control transformations. The white flowers were found to accumulate higher levels of chalcone synthase precursors and to have reduced levels of chalcone synthase message. A small-scale field trial was performed to evaluate the stability of the phenotype throughout a series of vegetative propagation steps and during plant growth. The white-flowering trait was maintained well through vegetative propagation; however, during growth of individual white-flowering plants, some pink color was found in some flowers. At one site 2% of the white-flowering plants produced a few pink flowers; at two other sites, as many as 10-12% of the plants produced pale pink flowers.

Acyltransferases↗