Natural genetic adaptation allows flexible reproductive behaviour: the case of wild carrot (Daucus carota L. subsp. carota) vs cultivated carrot (Daucus carota L. subsp. sativus)

Context Comparing the life cycles of wild and cultivated carrots is vital for identifying any overlapping flowering periods, as wild carrots have the potential to compromise the genetic purity of commercial carrot seeds via pollen flow. However, little information is known about how juvenility, vernalization, and their interactions impact the flowering pattern of wild and cultivated carrots in New Zealand. Aims We evaluated the influence of different juvenile phases, and vernalization phases on floral characteristics and flowering behaviour of cultivated and wild carrots. Methods The study was a factorial randomized complete block design with four blocks of five plants per block, incorporating treatments of different carrot genotypes (G1, cultivated; G2, wild carrots), juvenile phases (J1, 12 weeks; J2, 8 weeks; J3, 4 weeks), and vernalization phases (V1, 12 weeks; V2, 4 weeks; V3, no vernalization). Flowering percentage, flowering time, percentage of overwinter survival, and floral traits, including number of umbels and branches, and height of floral stem were recorded and analyzed by ANOVA. Key results Cultivated carrots flowered only when exposed to 12 weeks vernalization, while wild carrots have shown 100% flowering across all treatment combinations. Wild carrots exhibited a higher overwintering survival rate (94.9–100%) than cultivated carrots (66.1–98.3%). Prolonged exposure to vernalization significantly affected the floral traits of wild carrots. Conclusions There is a high likelihood of overlapping flowering periods between wild and cultivated carrots, as wild carrots can survive as both winter and summer annuals. Implications To avoid undesirable pollen flow during overlapping flowering periods of wild and cultivated carrots, we recommend timely weed management strategies to control wild carrots.