Somatic Embryogenesis in Tropical Fruit Trees

Biotechnological advances in guava (Psidium guajava L.): recent developments and prospects for further research

“…Contrarily, Biswas et al (2005) did not obtain somatic embryos on MS, B5 or N6 culture media; thus they used a modified GSEM (guava somatic embryogenesis medium) for the induction of somatic embryogenesis. Moreover, all the above-said media have high levels of ammonia and nitrate salts, which played a key role in the induction of somatic embryogenesis (Akhtar et al 2000). Nitrogen in the form of amino acid such as L-glutamine and organic compounds such as ascorbic acid has been effective in induction of somatic embryogenesis in guava (Chandra et al 2004;Kosky et al 2005;Biswas et al 2005).…”

“…In guava, considerable efforts have been made for in vitro regeneration via somatic embryogenesis (Akhtar 1997;Akhtar et al 2000;Chandra et al 2004Chandra et al , 2005aBiswas et al 2007;Kosky et al 2005;Rai et al 2007). Immature zygotic embryos have been utilized as the primary explants for the induction of somatic embryogenesis by most of workers.…”

“…Nitrogen in the form of amino acid such as L-glutamine and organic compounds such as ascorbic acid has been effective in induction of somatic embryogenesis in guava (Chandra et al 2004;Kosky et al 2005;Biswas et al 2005). The importance of reduced nitrogen, certain amino acids, organic, and inorganic nutrients has been reviewed in other tropical fruit species by Akhtar et al (2000). PGRs play an important role in the induction of either unorganized callus growth or polarized growth leading to somatic embryogenesis (Arnold et al 2002;Rai et al 2007).…”

“…Induction of somatic embryogenesis in guava was affected by nature of explants, physiological age of explants, duration of treatment of 2, 4-dichlorophenoxyacetic acid (2, 4-D) to explant, an interactive effect of 2, 4-D and sucrose, different PGRs and their combination, and genotype (Akhtar et al 2000;Rai et al 2007). …”

In vitro morphogenesis in zygotic embryo cultures of neem ( Azadirachta indica A. Juss.)

“…However, a few papers (Sarker et al 1997;Salvi et al 2001) reported direct shoot proliferation from seedling explants, but these papers lack details regarding the rate of shoot proliferation, frequency of rooting and transplantation survival. For many recalcitrant species, such as cereals, cotton and pines, immature zygotic embryos are the most suitable explants with which to establish regenerating cultures because of their juvenile nature (Bhojwani and Razdan 1996), and have been found to be the best starting material for induction of somatic embryogenesis in many perennial crops (Akhtar et al 2000). Embryo culture is a well-established plant breeding tool in raising rare hybrids, which are normally lost due to post-zygotic sexual incompatibility (Bhojwani and Razdan 1996), and has been widely used for studying factors that control normal embryogenesis during sexual reproduction (Custers and Bergervoet 1990;Monnier 1990;Liu et al 1993).…”