Micropropagation and somatic embryogenesis in sugarcane

Abstract

Sugarcane propagation through conventional means does not provide sufficient planting material of a variety, particularly desirable in case of newly released varieties to achieve large-scale dissemination; this is attributed to slow rate of seed multiplication by conventional sett planting. On the other hand, micropropagation technique of tissue culture ensures production of disease-free and true-to-type planting material of popular (new as well as old) varieties in an abundant quantity in a short period of time. The cultures of meristematic buds or spindle leaves, collected from healthy plants, are established aseptically under controlled nutritional and environmental conditions in vitro, followed by multiplication of shoots and induction of roots; the plantlets are hardened and supplied to growers. Somatic embryogenesis is the process of embryo formation and development from somatic cells of an explant under in vitro conditions. The somatic cells in culture can follow two pathways for somatic embryogenesis, either direct or indirect. The plants regenerated through direct somatic embryogenesis are often uniform; thus, the pathway finds use in clonal propagation and genetic transformation of sugarcane genotypes. In indirect somatic embryogenesis pathway, first callus is induced from cultured explants under the influence of an auxin (mostly 2, 4-D) which is then regenerated into plants; such plants may exhibit somaclonal variation.