Effect of storage conditions on conservation of sorghum shoot tips in calcium alginate beads

Sorghum artificial seeds were obtained through encapsulation of somatic embryos or adventitious buds in calcium alginate beads. In this paper, the effect of storage conditions on viability of encapsulated plant materials was studied. To obtain plant material for encapsulation, axillary and adventitious buds without shoot development were obtained on seedling shoot tips cultured on MS medium supplemented with 2mg/l BAP and 0.5 mg/l 2,4-D under light condition (100 μmol m-2s -1). Subculture of the obtained shoot tips in two weeks intervals resulted in the formation of about 759,375 shoot tips/explants in three months. At the same period, shoot explants cultured on MS medium supplemented with 3 mg/l 2,4-D resulted in the formation of about 270 somatic embryos including embryo maturation in four weeks on MS medium supplemented with 0.56 mg/l BAP and 0.1 mg/l NAA. In sorghum, where artificial seeds can be obtained using of in vitro derived buds or embryos, buds were recommended due to feasibility to obtain high number of plant materials with good quality in short time, the essential need for mass production of artificial seeds. Storage of the encapsulated plant materials in liquid MS medium supplemented with 4 mg/l BAP and 0.5 mg/l 2,4-D in laboratory refrigerator was recommended, where the encapsulated plant materials conserved its potential to convert. Isenzyme studies indicated that alginate matrix exerted slight changes in isozyme expression in encapsulated plant materials.