Fitness effects of somatic mutations accumulating during vegetative growth

Abstract The unique life form of plants promotes the accumulation somatic mutations that can be passed to offspring in next generation, because same meristem cells responsible for vegetative growth also generate gametes sexual reproduction. However, little is known about consequences mutation fitness. We evaluate fitness effects Mimulus guttatus by comparing progeny from self-pollinations made within flower (autogamy) between stems on plant (geitonogamy). are evident this comparison, as autogamy leads homozygosity a proportion mutations, but geitonogamy remain heterozygous each stem. In two different experiments, we find consistent individual stems. Surprisingly, several groups autogamous crosses displayed increases compared crosses, likely indicating beneficial occurred some These results support hypothesis accumulate during growth, they filtered forms selection occur throughout development, resulting culling expressed deleterious and retention mutations.