Plant regeneration from cultured protoplasts of the cooking banana cv. Bluggoe (Musa spp., ABB group)

Abstract

Suspensions of embryogenic cells of a triploid banana (Musa spp., cv. Bluggoe) were initiated from the uppermost part of meristematic buds, and used as protoplast source. After 20 weeks in culture, the suspension contained a mixture of globular structures or globules and embryogenic cell clusters, as well as single cells. Two types of protoplasts were obtained from embryogenic suspension culture: small (20-30 μm) and larger (30-50 μm) protoplasts with a dense cytoplasm and large starch grains respectively. The small protoplasts probably originated from embryogenic cell clusters, and also from pseudocambial cells of globules, while larger protoplasts were probably released from oval starchy cells and those of the globule peripheral area. In co-culture with a suitable feeder, consisting of suspensions of diploid banana cells, the protoplasts of triploid banana reformed the cell wall within 24 h and underwent sustained divisions leading to the formation of small clusters of 2-3 cells within 7 days. The latter developed directly into embryos without passing through an apparent callus phase. 10% of such embryos gave rise to plantlets when subcultured in 2.2 μM 6-benzylaminopurine and 2 μM 4 amino-3,5,6-trichloropicolinic acid for 1 week, before transfer to MS medium containing 10 μM 6-benzylaminopurine. The rest of the embryos underwent intensive direct secondary embryogenesis which could lead to the formation of plantlets with a frequency of up to 50% upon further transfer to hormone-free medium.

An Improved Protocol for Microcallus Production and Whole Plant Regeneration from Recalcitrant Banana Protoplasts (Musa spp.)

“…A number of asexual methods like cell suspension cultures (Novak et al, 1989;Ma, 1991;Dhed'a et al, 1991;Coˆte et al, 1996), anther and microspore cultures (Assani et al, 2003), protoplast engineering (Megia et al, 1993;Panis et al, 1993;Matsumoto and Oka, 1998;Assani et al, 2001; have been successfully used in banana.…”

Somatic hybrids obtained by asymmetric protoplast fusion between Musa Silk cv. Guoshanxiang (AAB) and Musa acuminata cv. Mas (AA)

“…Since protoplast regeneration systems in several banana cultivars had already been established (Megia et al 1993;Panis et al 1993;Matsumoto and Oka 1998;Assani et al 2001;Assani et al 2002;Assani et al 2006;Xiao et al 2007;Xiao et al 2008), the use of cell fusion techniques in banana breeding becomes a realizable objective. At present, very limited successes of somatic hybridization of banana have been reported though Matsumoto et al (2002) firstly reported symmetric somatic hybridization between non-treated cv.…”

Protoplast isolation and culture for banana regeneration via somatic embryogenesis

“…Protoplasts are then cultivated in appropriate conditions and form the cell wall, then undergo divisions leading to embryos, which develop into plantlets [7].…”