Full Length Research Paper

Infection pathways of soft rot pathogens on Amorphophallus konjac

Jinping Wu^1,2, Ying Diao¹, Yucheng Gu² and Zhongli Hu¹*

Key Lab of the Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, Wuhan 430072, China.

²Industrial Crops Institute of Hubei Academy of Agricultural Sciences, Wuhan 430064, China.

*Corresponding author. E-mail: huzhongli@whu.edu.cn. Tel: 86 27 68753611.

Fax: 86 27 68753611.

Accepted 20 May, 2010

Abstract

With the rapid expansion of cultivated land, bacterial soft rot of konjac is more and more serious. The main pathogen is Erwinia carotovora subsp. carotovora. Some researchers think the natural openings and wounds are the main infection pathways on konjac. In this study, the infection pathways are investigated. From macro-observation, the soft-rot pathogens could not directly invade the intact corms, but it could invade the infected corms through the new rots. At the same time, bud scales, roots and wounded corms could be directly infected. From micro-observation, the epidermis of the corm had no stomas and lenticels, the stomas of the bud scales had no pathogens gathered around, and the pathogens broke down the infected roots and bud scales cells layer by layer. The results showed that soft rot pathogens invaded Amorphophallus konjac through the wounds and the growth of the organizations rather than the natural openings.

Key words: Amorphophallus konjac, bacterial soft rot, infection pathways.