ABSTRACT
Climate change will impact the carrot seed industry globally. One adaptation strategy to limit climatic impacts on the production of commercial carrot seeds is geographical shift. However, production must be shifted to climate-optimal places that are free from weeds such as wild carrots to avoid genetic contamination via hybridization. The process of gene flow between wild and cultivated carrots is critical to enable management of wild carrots in the face of climate change. This review systematically assesses the resilience of wild carrots to climate change and their impact on commercial carrot seed production globally with a focus on New Zealand as a major carrot seed producer. The literature was critically analyzed based on three specific components: i) resilience of wild carrots to climate change ii) genetic contamination between wild and cultivated carrots, and iii) management of wild carrots. The majority of the articles were published between 2013 and 2023 (64.71 %), and most of these studies were conducted in Europe (37.26 %) and North America (27.45 %). Country-wise analysis demonstrated that the majority of the studies were carried out in the United States (23.53 %) and the Netherlands (11.77 %). There was limited research conducted in other regions, especially in Oceania (1.96 %). Spatial distribution analysis revealed that the wild carrot was reported in around 100 countries. In New Zealand the North Island has a higher incidence of wild carrot invasion than the South Island. The findings indicated that the wild carrot is becoming more adaptable to climate change, compromising the genetic purity of cultivated carrots due to pollen flow from wild to cultivated carrots. Therefore, ongoing research will be helpful in developing sustainable weed management strategies and predicting potential geographical invasiveness. This study provides a guide for scientists, policymakers, industrialists, and farmers to control wild carrots and produce genetically pure commercial seeds amid climate change.
Subject(s)
Climate Change , Daucus carota , Gene Flow , Daucus carota/genetics , New Zealand , Pollen , SeedsABSTRACT
New Zealand is a major producer of carrot seeds globally. Carrots are an important nutritional crop for human consumption. Since the growth and development of carrot seed crops mainly depend on climatic factors, seed yield is extremely susceptible to climate change. This modeling study was undertaken using a panel data approach to determine the impact of the atmospheric conditions (proxied by maximum and minimum temperature) and precipitation during the critical growth stages for seed production in carrot, viz., juvenile phase, vernalization phase, floral development phase, and flowering and seed development phase on carrot seed yield. The panel dataset was created using cross-sections from 28 locations within the Canterbury and Hawke's Bay regions of New Zealand that cultivate carrot seed crops and time series from 2005 to 2022. Pre-diagnostic tests were performed to test the model assumptions, and a fixed effect model was selected subsequently. There was significant (p < 0.01) variability in temperature and rainfall throughout different growing phases, except for precipitation at the vernalization phase. The highest rate of changes in maximum temperature, minimum temperature, and precipitation were recorded during the vernalization phase (+0.254 °C per year), floral development phase (+0.18 °C per year), and juvenile phase (-6.508 mm per year), respectively. Based on marginal effect analysis, the highest significant influence of minimum (187.724 kg/ha of seed yield decrease for each 1 °C increment) and maximum temperature (1 °C rise increases seed yield by 132.728 kg/ha), and precipitation (1 mm increment of rainfall decreases the seed yield by 1.745 kg/ha) on carrot seed yield were reported at vernalization, and flowering and seed development, respectively. The minimum and maximum temperatures have a higher marginal effect on carrot seed production. Analysis of the panel data demonstrates that the production of carrot seeds will be vulnerable to climatic change.
