Direct somatic embryogenesis and organogenesis pathway of plant regeneration can seldom occur simultaneously within the same explant of sorghum uri icon

abstract

  • Sorghum (Sorghum bicolor) is an important staple foodcrop, especially of the poor in Africa, Asia and CentralAmerica and needs to be improved through geneticengineering. Generation of transgenic plants dependsmainly on the standardization of an efficient tissue cultureand regeneration protocol. Sorghum tissue culture andregeneration protocols mostly follow either organogenesis(Maheswari et al. 2006) or direct somatic embryogenesispathway (Harshavardhan et al. 2002). Following theprotocol of Girijashankar et al. (2005), we attempted toproduce transgenic sorghum with synthetic Bt geneconstructs (ubicry1Ab and ubicry1Ac, separately).However, molecular analysis of the T0 and their progenyplants revealed the loss of germline transmission of therespective transgenes under study. Recent studies byWang et al. (2005) with Agrobacterium-mediatedtransformation of maize (Zea mays) and regenerationthrough embryogenic callus, reported the absence oftransgenes in the progeny plants. We report here theoccurrence of different types of calli, few of which arenot expected to occur during the direct somaticembryogenesis pathway of sorghum regenerationprotocol followed to obtain the above transgenic plants

publication date

  • 2007