Nodal Culture of Flower Stalk of Lettuce, Lactuca sativa and L. serriola

Abstract

Nodal culture of flower stalk was carried out to maintain the breeding line of lettuce. The flower buds of lettuce and its interspecific hybrids with Lactuca serriola and tetraploid lettuce were initiated on 40th to 34th node of main stem and bloomed at 140 to 110 days after sowing. The explants from node of secondary stem of tetraploid lettuce and L. serriola × lettuce proliferated leaf buds in a rate of 44.8 and 19.9%, respectively, indicating that the explants from the developed stage of flower seemed to form flower bud rather than leaf bud or shoot. Then, the explants of secondary stem from the lower node of the main stem showed higher shoot formation than those from the upper node. When the terminal flower of the main stem bloomed, the percentage of explants which formed leaf buds (5.6%) was less than that of none-bloomed explants (55.1%). Explants from lower node of secondary stalk formed leaf bud more frequently than those of upper node. This study enables the maintenance of the plants on breeding lines of lettuce even after the seed production by node culture of flower stalk.