Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/10/2003
Publication Date: 11/15/2003
Citation: Aburomia, R., Grube, R.C. Propagation of selected lettuce germplasm by regeneration of apical and axial buds. Meeting Abstract. Proceeding of the Annual Meeting of the International Plant Propagators' Society. Portland, Oregon. 2003. Interpretive Summary: N/A
Technical Abstract: Successful lettuce (Lactuca sativa) breeding requires evaluation, selection, and recovery of seeds from field grown plants. The recovery of germplasm from fields with a high pathogen population can be challenging because plants die before setting seed. We developed a vegetative propagation procedure that uses a rootcube substrate to establish whole rooted plants from apical and axial expanded buds from field grown lettuce. Buds were first excised from plants and then immersed or their bases dipped in commercially available formulations of rooting hormone. Following hormone treatment, buds were placed in rootcubes in a growth chamber for 14 days and allowed to harden off for 5 days, prior to being transplanted into potting soil mix. To determine an effective rooting hormone application method and concentration, bud survival from a field grown romaine cultivar was evaluated in four powder dip treatments, four total immerse treatments, and one no-treatment control. Lower concentration aqueous formulations performed best on romaine buds, and 150ppm IBA in water was used to test the regeneration of buds from other lettuce types. Lettuce plants from two fields, representing cultivars of green leaf, red leaf, romaine, and crisphead types wee used as sources of buds to be vegetatively propagated. Buds from the crisphead cultivar, Salinas responded significantly better in one field to IBA treatment than other types. On selected germplasm in a pathogen infested field vegetative propagation procedure preformed well compared to digging whole plants and transplanting. Given its efficiency and the ability to exclude pathogens from the explant, this propagation technique has advantages over both, tissue culture and transplanting entire plants with intact roots.