Setaria italica L. - A model genetic system for studying drought tolerance.

Abstract

Studies in genetic systems and molecular biology are progressing at an impressive rate, so it is the need of the hour to search for new model organism to address specific challenges in agriculture, one such important challenge being abiotic stress tolerance. Understanding drought tolerance at molecular level particularly identification of relevant genes is likely to pave the ways for mitigating the drought stress losses in major crops. Foxtail millet is thought to be an excellent experimental model in studying abiotic stress tolerance system due to its small genome (1 C ~ 515 Mb; 2n = 2x = 18), low amount of repetitive DNA, a highly conserved genome structure relative to the ancestral grass lineage, inbreeding nature and short life cycle (Doust et al., 2009, Devos et al., 1998; Jayaraman et al., 2008). As a genetic model it has many desirable traits, including small size (10–15 cm), a short life cycle (6–9weeks), and prolific seed production (~13,000 seeds per plant). The genome size of foxtail millet is very much similar to that of rice at genome level and is also one of the smallest among the Panicoid grasses. Hence, it is thought to be an excellent drought tolerant crop with an extensive germplasm collection, providing opportunities to study the various biological processes and to mine for novel allelic variation.