Introgression of reproductive traits from Trifolium nigrescens increases the seed yield of white clover (Trifolium repens L.)

Interspecific hybrids between white clover and the annual, profuse flowering ball clover have been developed as a strategy to improve the potential seed yield of white clover. The seed yield and seed yield components of advanced white clover × ball clover hybrids were compared with white clover in replicated field experiments over two harvest years. The backcross 3 hybrid had more reproductive nodes per stolon than the control variety 'AberHerald' which was reflected in more inflorescences per unit area but inflorescences with fewer florets and seeds. The hybrid had a greater potential seed yield than the control variety in 2002 but not 2001. Backcross 3 hybrids have also been produced across the range of leaf size categories. Medium and large leaved hybrids produced significantly more inflorescences and a higher potential seed yield than control varieties of comparable leaf size in both harvest years. The small leaved hybrid was not significantly greater than the control variety 'AberDale' in either inflorescence production or seed yield.