Successful development of a shed-microspore culture protocol for doubled haploid production in Indonesian hot pepper (Capsicum annuum L.)

Various systems of anther and microspore cultures were studied to establish an efficient doubled haploid production method for Indonesian hot pepper (Capsicum annuum L.). A shed-microspore culture protocol was developed which outperformed all the previously reported methods of haploid production in pepper. The critical factors of the protocol are: selection of flower buds with more than 50% late unicellular microspores, a 1 day 4°C pretreatment of the buds, followed by culture of the anthers in double-layer medium system for 1 week at 9°C and thereafter at 28°C in continuous darkness. The medium contained Nitsch components and 2% maltose, with 1% activated charcoal in the solid under layer and 2.5 μM zeatin and 5 μM indole-3-acetic acid in the liquid upper layer. All the ten genotypes of hot pepper tested, responded to this protocol. The best genotypes produced four to seven plants per original flower bud. This protocol can be used as a potential tool for producing doubled haploid plants for hot pepper breeding.