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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)

Asharp Godwin , Simone Pieralli, Svetla Sofkova-Bobcheva, Craig McGill

Abstract

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. A pot experiment was conducted to evaluate the influence of different juvenile phases, and vernalization phases on floral characteristics and flowering behaviour of cultivated and wild carrots. Methods. The study was executed in a factorial randomized complete block design with 4 blocks of 5 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). Observations on 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 as a 3-way ANOVA. Key results. Flowering of cultivated carrots was observed only when they were exposed to a 12-week vernalization treatment. Wild carrots have shown 100 % flowering across all treatment combinations. Wild carrots exhibited a higher overwintering survival rate (94.9 % - 100 %) compared with cultivated carrots (66.1 % - 98.3 %). Prolonged exposure to vernalization significantly (p<0.05) affected the floral traits of wild carrots. Conclusions. The findings demonstrate a high likelihood of overlapping flowering periods between wild and cultivated carrots in New Zealand, 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, it is recommended to execute timely weed management strategies to control wild carrots, considering their winter and summer annual life cycle behaviour.

CP24320  Accepted 10 December 2024

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