Development of phenolic compounds in maize anthers (Zea mays) during cold pretreatment prior to androgenesis

Androgenic capacity has been developed for some time in maize (Zea mays L.) and cold pretreatment of anthers, e.g. for 14 days at 7 degrees C, is considered necessary to induce androgenesis in this species. During this period, development of anther phenolic content and of IAA protection capacity of a phenolic extract were studied in three genotypes that respond differently to anther culture. Phenolic compounds were analyzed by HPLC and found to be mainly represented by six flavonol heterosides. Their levels were highly variable during the cold treatment, both between and within genotypes. These phenolics modified the in vitro degradation of IAA by IAA-oxidase. The extract from the most responsive genotype to androgenesis, DH5 x DH7, gave maximal protection of IAA, whereas the ones from Seneca 60 and A188 (low-responsive and unresponsive, respectively) showed an IAA degradation capacity.