An overview of the molecular and biochemical components of seed dormancy and germination in Brassica napus

Seed dormancy and germination determines the ecological adaptation and sustainability of seed plants. Intensive research efforts have identified the role of several factors in seed dormancy and germination. The major factors are phytohormones, dormancy-specific genes, chromatin factors, developmental and/or structural components of seeds, and exogenous environmental cues, which have been well studied in model plants like Arabidopsis and rice. In general, Brassica napus L. (canola) cultivars and its interspecific hybrids show seed heterogeneity and varying degrees of dormancy, and germination potentials. However, detailed research on understanding the molecular mechanisms of seed dormancy and germination in B. napus is limited as compared to othe model crops like Arabidopsis . Identification of seed dormancy and germination associated QTLs in concert with environmental factors is essential for better management of seed longevity and vigor in economically important oil-seed crops like B. napus . In addition, both maternal and paternal genomes and/or their imprinted genes are often known to influence dormancy and subsequently lead to premature germination in some interspecific hybrids. Thus, in this review we provide an overview on plausible role of genetic, physiological, and environmental factors governing seed dormancy, germination and premature germination traits in B. napus .