Identification of risk areas for Orobanche cumana and Phelipanche aegyptiaca in China, based on the major host plant and CMIP6 climate scenarios

Parasitic broomrape of the genus Orobanche poses a formidable threat to producing many crops in Europe, Africa, and Asia. Orobanche cumana and Phelipanche aegyptiaca are two of China's most destructive root parasitic plants, causing extreme sunflower, tomato, melon, and tobacco damage. However, the potentially suitable areas of O. cumana and P. aegyptiaca in China have not been predicted, and little is known about the important environmental factors that affect their extension. Due to their invasiveness and economic importance, studying how climate change and host plants may affect broomrapes' distribution is necessary. In the study, we first predicted the potentially suitable areas of the invasive weeds (O. cumana and P. aegyptiaca) and their susceptible host plants (Helianthus annuus and Solanum lycopersicon) using MaxEnt. Then, the risk zones and distribution shifts of two broomrapes under different climate conditions were identified by incorporating the distribution of their susceptible host plants. The results highlighted that the potential middle- and high-risk zones for O. cumana and P. aegyptiaca amounted to 197.88 x 10(4) km(2) and 12.90 x 10(4) km(2), respectively. Notably, Xinjiang and Inner Mongolia were the highest-risk areas within the distribution and establishment of O. cumana and P. aegyptiaca. Elevation and topsoil pH were the decisive factors for shaping O. cumana distribution; precipitation seasonality and annual precipitation were the dominant bioclimatic variables limiting the spread of P. aegyptiaca. The potentially suitable areas and risk zones of O. cumana would decrease significantly, and those of P. aegyptiaca would fluctuate slightly under future climate change scenarios. Overall, our study suggested that the two broomrapes' risk zones will significantly northward to higher latitudes. The results will provide suggestions for preventing O. cumana and P. aegyptiaca.

Automated summary

Parasitic broomrape plants Orobanche cumana and Phelipanche aegyptiaca pose a serious threat to crops in China, but their potential suitable areas and risk zones have not been accurately predicted. This study used MaxEnt to predict their potential suitable areas and identified the factors affecting their distribution. The results showed the potential risk zones of O. cumana and P. aegyptiaca and suggested that their risk zones will shift northward under future climate change scenarios.