Light isn't strictly necessary for germination in most plant species. However, some seeds germinate best in absolute darkness, and others perform well with continuous sunlight. Light does become vital for every species after germination, because the initial sprout will not survive if it cannot reach a light source.

Do seeds germinate better in sunlight?

Most seeds germinate best under dark conditions and might even be inhibited by light (e.g., Phacelia and Allium spp.). However, some species (e.g., Begonia, Primula, Coleus) need light to germinate (Miles and Brown 2007). Don't confuse seed light requirements with what seedlings need. All seedlings require sunlight.

What is the effect of sunlight in seed germination?

Seed germination induce by many factors, one of them are light colors. Germination is regulated by a pigment, phytochrome, which is sensitive to different wavelenghts of light. When far red light is receive the phytochrome equilibrium changes towards the red light absorbing form.