Seed and forage yield of advanced generation synthetics of berseem clover derived from partly inbred parents under different harvesting regimes.

摘要

Selfing of potential parents in outbred species could favour the elimination of deleterious recessive alleles and accumulation of favourable alleles with additive genetic effects. This study assessed the effects of five selfing levels (from S₀ to S₄) and two genetic bases (wide, six parental populations; narrow, three populations) on the seed and forage yields and the leaf/stem dry-weight ratio of the Syn-1 and Syn-2 generations of synthetic varieties of berseem clover (Trifolium alexandrinum L.) obtained from parents selected for self-fertility. The material was evaluated over 2 years in southern Italy under three crop management schemes. The management with one forage harvest at early flowering before seed harvest maximized both the seed and forage yields. One cycle of selfing produced the highest selection gains for the seed and forage yields. The genetic bases had less influence on production traits than the selfing levels, but the wide-based synthetics tended to outyield the narrow-based ones. The effects of the selfing generations and the genetic bases were largely additive and consistent across the treatments, years and generations of synthetics.Digital Object Identifier http://dx.doi.org/10.1111/j.1439-0523.2011.01875.x