科研之友
微信
新浪微博
Facebook
分享链接
摘要
Chestnut rose (Rosa roxburghii) shows promising prospects both in fruit exploitation and ornamental plant genetic improvement. Powdery mildew is the most destructive fungal disease of this species and its relatives. The infection date, disease duration, peak disease indexes (PDI), and area under the disease progress curve (AUDPC) values were used to rate the resistance to powdery mildew disease in seven genotypes of chestnut rose and their eight relatives. R. sterilis, R. kweichonensis, R. laevigata. R. lucidissima, and R. chinensis were free from powdery mildew, whereas R. multiflora var. multiflora and R. multiflora var. cathayensis were the most susceptible to this disease. Of the genotypes from R. roxburghii, 'Guinong No. 6' exhibited a significantly high level of resistance with striking brown necrotic lesions in its leaves, whereas 'Guinong No. 5' and 'Guinong No. 2' showed the most susceptibility. The resistance ratings identified by AUDPC were significantly correlated with those characterised by PDI. Therefore, it is suggested that the latter is used in the resistance ratings because of its simplicity.
