Open AccessShoot Organogenesis and Plant Regeneration from Cotyledons of Diploid, Triploid, and Tetraploid Watermelon
Author(s) -
Michael E. Compton,
D. J. Gray
Publication year - 1993
Publication title -
journal of the american society for horticultural science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.408
H-Index - 80
eISSN - 2327-9788
pISSN - 0003-1062
DOI - 10.21273/jashs.118.1.151
Subject(s) - explant culture , shoot , cotyledon , organogenesis , biology , citrullus lanatus , botany , seedling , basal shoot , murashige and skoog medium , callus , germination , micropropagation , horticulture , in vitro , biochemistry , gene
Adventitious shoots were obtained from watermelon [ Citrullus lanatus (Thunb.) Matsun. & Nakai] cotyledons incubated on a modified Murashige and Skoog medium containing BA. Initial experiments comparing the effects of BA (0, 5, 10, or 20 μ m ) and IA4 (0, 0.5, or 5 μ m ) demonstrated that BA was required for adventitious shoot formation but its concentration in the medium was not critical. The addition of IAA to medium with BA increased callus production and inhibited shoot formation. However, the percentage of responding explants in the best treatment was 90% for `Minilee', 64% for S86NE, and 50% for `Jubilee II' when explants were prepared from 5-day-old seedlings. Explants from nongerminated embryos or seedlings germinated for 10, 15, or 20 days produced fewer shoots. The effect of several cytokinins on shoot organogenesis was then examined using the optimized protocol. The percentage of explants with shoots and the number of shoots per explant were about two to four times higher when 5 to 10 μ m BA was used compared to the most effective kinetin (20 μ m ) or thidiazuron (0.1 μ m ) concentration. The percentage of explants with shoots and the number of shoots per explant were greater for diploid (57% and 2.2, respectively) than for triploid (22% and 0.6, respectively) or tetraploid (20% and 0.8, respectively) lines. Chemical names used: N -(phenylmethyl)-1 H -purin-6-amine (BA); 6-furfurylaminopurine (kinetin); N -phenyl- N' -1,2,3-thiadiazol-5-ylurea (thidiazuron); 1 H -indole3-acetic acid (IAA).