02815naa a2200193 a 450000100080000000500110000800800410001910000190006024501360007926000090021530000110022450000390023552021560027465300310243070000170246170000160247870000170249477301100251119203092017-01-26       2011    bl ---       0--  u    #d1 aFALEIRO, F. G.  aComparison of culture media for regeneration of elephantgrass (Pennisetum purpureum Schum.) plants from mature seed derived callus.  c2011  ap. 23.  aFlorida Energy Systems Consortium.  aElephantgrass (Pennisetum purpureum Schum.) is a highly productive forage grass in tropical and subtropical regions and is also considered as one of the best adapted perennial feedstocks for biofuel production in the southern US. Biotechnology will significantly contribute to the genetic improvement of forage grasses and bioenergy feedstocks. However, a genetic transformation protocol is currently lacking for elephant grass. The first step to enable biotechnological approaches is the development of an efficient plant regeneration protocol from tissue culture. Among the most important factors influencing tissue culture response are genotype, explant and media composition. Using seeds as starting material for the establishment of tissue cultures has not been described for elephant grass. In contrast to immature tissues like immature leaves or inflorescences the use of seeds for initiation of regenerable tissue cultures has the benefit of providing explants throughout the year without the need of maintaining donor plants. In this study, the effect of media composition on tissue culture response of mature seeds derived from elephant grass N-74 was evaluated in a factorial design with 2 auxin sources, 3 auxin concentrations and 2 cytokinin concentrations. Additional media evaluating alternative cytokinin to auxin ratios and the supplementation with L-proline as well as light regimes during callus induction were also compared. This experiment was carried out in a completely randomized design with 5 replications. Each replication was represented by one petridish with 10 longitudinally cut mature seeds resulting in a total of 1,000 explants. The tissue culture response was evaluated for unintended germination, callus initiation, callus growth, necrosis, embryogenesis, plant regeneration rate and regeneration frequency. The means were compared using the Tukey test at 1% level of probability and using linear and non-linear regression analysis. The best media composition supported induction of callus from 100% of the cultured seed explants and embryogenic callus that regenerated plants from 37% of the cultured seed explants.  aPennisetum purpureum Schum1 aMANFREDO, S.1 aLUCIANI, G.1 aALTPETER, F.  tIn: ANNUAL FESC SUMMIT, 3., 2011, Florida. Oral and poster session: abstracts. [Gainesville: FESC, 2011].