2.2.5. Head Color

Broccoli is rich in anthocyanin, an important nutritional value with antioxidant activity, can improve health, increase life expectancy and prevent diseases [56]. Anthocyanin accumulation in broccoli inflorescences, especially in septals, makes the appearance range from green/blue to purple. Some cultivars, such as 'Purple Sprouting Early', are selected for rich anthocyanin contents, producing obvious purple heads [56]. Purple traits in *B. oleracea* are attributed to the independent activation of *Brassica oleracea MYB DOMAIN PROTEIN 2* (*BoMYB2*) in subspecies of cabbage, cauliflower, kohlrabi and possibly broccoli [57].

On the other hand, broccoli cultivars producing heads with green-purple color are considered not beautiful and would be less attractive to consumers than the completely green type, especially in the market of China [58]. This green-purple type is sensitive to temperature, and cool weather would induce and deepen the purple degree. Yu et al. mapped this purple sepal trait using a DH population and SLAF sequencing; three QTLs were detected, with a major locus, *qPH. C01–2*, located on linkage group (LG)1, and two loci, *qPH. C01–4* and *qPH. C01–5*, located near *qPH. C01–2* [59].
