Fig. 1

Histological characteristics of the roots of the mock and infected resistant and susceptible cultivars at the tillering stage (Z21) under scanning electron microscopy. a Epidermal cells of the mock resistant cultivar. b Epidermal cells of the infected resistant cultivar. c Epidermal cells of the mock susceptible cultivar. d Epidermal cells of the infected susceptible cultivar. e Vascular bundle cells and cortical parenchyma cells of the mock resistant cultivar. f Vascular bundle cells and cortical parenchyma cells of the infected resistant cultivar. g Vascular bundle cells and cortical parenchyma cells of the mock susceptible cultivar. h Vascular bundle cells and cortical parenchyma cells of the infected susceptible cultivar. The resistant cultivar was Mianyang 26/Yumai 47, and the susceptible cultivar was CU42. White arrows in (a-d) indicate epidermal cells, white arrows in (e-h) indicate cortical parenchyma cells, black arrows indicate vascular bundle cells, white circles in (f and h) indicate hyphae in cortical parenchyma cells, and black circles in (h) indicates hyphae in vascular bundle cells