Growth and regenerability of long-term suspension cultures of the U.S. rice cultivar Mercury

✍ Scribed by Herry S. Utomo; Timothy P. Croughan; Suzan S. Croughan

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 376 KB
• Volume: 44
• Category: Article
• ISSN: 0167-6857
• DOI: 10.1007/bf00048194

✦ Synopsis

Suspension cultures of the U.S. rice cultivar Mercury have been maintained in modified General Medium for more than 3 years. These suspensions have continued to have high and relatively stable regeneration rates. Two different explants, immature panicles and seeds, were compared during the development of these embryogenic suspensions. Initial formation of secondary embryogenic callus from immature panicles on induction medium was greater than that from seeds. Suspensions of these two cell lines, however, did not differ morphologically and maintained similar regeneration rates. After 5 months in culture the rates of regeneration began to decline. The suspensions were plated onto regeneration medium without growth regulators for 2 weeks and then embryogenic cells were manually selected and used to develop secondary suspensions. Through this simple rejuvenation procedure, the suspensions retained high and stable regeneration rates. Variability in suspension growth, however, was observed during the culture period. Slower growth occurred at weeks 13, 15, 27, and 29 and was associated with a decrease in regeneration rates. Reproductive fertility of regenerated plants remained high for 3.5 years but then declined.