
%0 Journal Article
%A Magdalita, PM 
%A Adkins, SW 
%A Godwin, ID 
%A Drew, RA 
%T An Improved Embryo-Rescue Protocol for a <I>Carica</I> Interspecific Hybrid
%J Australian Journal of Botany
%D 1996/06/01
%V 44
%N 3
%P 343-353
%K 
%R https://doi.org/10.1071/BT9960343
%U https://www.publish.csiro.au/paper/BT9960343 
%X An improved embryo-rescue protocol was developed for embryos (90 days old) of Carica papaya L. (Clone 2001), and subsequently was utilised for efficient production of interspecific hybrids of C. papaya &#215; C. cauliflora Jacq. from 90- to 120-day-old embryos. Pre-incubation of C. papaya embryos for 7 days on a germination medium containing half-strength De Fossard nutrients supplemented with gibberellic acid (10 &#956;M), 6-benzylamino-purine (0.25 &#956;M), alpha-naphthalene-acetic acid (0.25 &#956;M). sucrose (58 mM) and agar (8 g L-1) supported 100% germination. Subsequent transfer of germinated embryos to a nutrient medium that was identical, except that it was free of plant growth regulator, allowed good growth but induced shoot etiolation and callus production. Reducing the pre-incubation of C. papaya embryos on this medium to 5 days before transfer to the medium free of plant growth regulator produced similarly high germination (96%), but allowed for the production of good quality seedlings that were unetiolated and free of unwanted callus. For interspecific hybrids, a 5-day pre-incubation of the embryos on a liquid formulation was better than the solid formulation as it promoted better growth and vigour of the normally abortive interspecific hybrid embryos. Using the improved protocol, 1981 of 2100 (94%) interspecific hybrid embryos consisting of single and multiple forms were germinated. In all cases, the germinating multiple embryos underwent further embryogenesis that allowed for the production of 485 (25%) morphologically normal hybrid plants grown in soil in the glasshouse. 
