Polyploidy breeding in mulberry - A review

Mulberry foliage constitutes the sole food for silkworm, Bombyx mori L. and thus has been supporting the silk industry since time immemorial. The success of this industry is largely determined by leaf yield potential and leaf quality of mulberry. Therefore, it is important to develop superior mulberry varieties which can adequately suffice the needs of farmers. To achieve this goal, plant breeders mostly use conventional breeding as a tool to combine desirable traits of two parents in a single mulberry variety by cross pollination. However, owing to several drawbacks, a more efficient method of polyploid breeding has gained importance in recent years. The superiority of triploids, particularly in terms of nutritive value and yield, over other ploidy levels has been well documented in mulberry. Colchicine, a mutagenic agent, has been successfully used in several crops including mulberry to induce polyploidization. An overview of this breeding technique will give an insight on how it can be exploited to develop triploids with desirable traits and assist plant breeders to design mulberry breeding strategies.