In vitro regeneration, somatic hybridization and genetic transformation studies: an appraisal on biotechnological interventions in grasses

The grass family Poaceae is one of the largest groups of monocots comprising approximately 650-900 genera and 10,000 species. Grasses include plants with wider environmental adaptability sustaining extremes of cold, heat, drought, and dominant in its distribution on variety of landscapes world over. Conventional approaches have contributed substantially in the past for the genetic improvement of grasses. However, the necessity of improvement for quality traits, nutritional value and as biofuel source has sought biotechnological interventions in grasses. Regeneration of grasses is a prerequisite for genetic manipulation in vitro. Last one decade, has seen accumulation of large amount of literature in grass on in vitro regeneration. Further, against the background of the limitations for transferring polygenic traits coupled with prevalent innate sexual incompatibilities, somatic hybridization through protoplast fusion may be a possible option for gene transfer within grasses and from grasses to lead cereals. In addition, grasses gain additional importance by realizing novel nuclear-cytoplasm-genome combinations from somatic fusion products. There are no detailed recent reviews available depicting overall research progress with major emphasis on in vitro plant regeneration, somatic hybridization and genetic transformation in grasses. In the present review, attempts is made towards making a inclusive survey illustrating research findings on in vitro regeneration, somatic hybridization and genetic transformation studies covering last one decade. Mention of a few new and novel developments for grass genetic improvement using biotechnological approaches is discussed in this review.