Full Length Research Paper

Response of arum lily calli to culture filtrate of Pectobacterium carotovorum subsp. carotovorum

Lianghua Ni^1#, Xiaolu Li^1#, Jan B. M. Custers², Keqin Zhang¹ and Lemin Zhang¹*

¹Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, China.

²Plant Research International, Wageningen University and Research Centre, PO Box 16, 6700 AA Wageningen, The Netherlands.

*Corresponding author. E -mail: zhanglm@ynu.edu.cn. Tel: +86-871-5031092.

Fax: +86-871-5034838.

Abbreviations: PCC, Pectobacterium carotovorum sp. carotovorum; Prt, protease; Peh, polygalacturonase; Pel, pectate lyase.

^#These authors contributed equally to this paper

Accepted 11 September, 2009

   Abstract

This report demonstrated that culture filtrate of Pectobacterium carotovorum ssp. carotovorum isolate ZT0505, the pathogen of bacterial soft rot disease of arum lily (Zantedeschia sp.), contained extracellular enzymes and caused arum lily leaf tissue and callus maceration. Arum lily leaf tissue and callus sensitivity to culture filtrate coincided with the host susceptibility to the pathogen. The rates of survival of callus pieces were determined after exposure for various times to culture filtrate. Survival of callus pieces (%) increased with reduction of exposure time from 20 to 14 h and from 14 to 8 h. One out of 30 callus pieces was still viable after 3 cycles of 8 h exposure. Subsequently, the surviving cells in this callus pieces proliferated and differentiated into shoots. Based on this initial work, the callus screening using culture filtrate as selection agent may be useful for in vitro selection of soft rot resistant germplasm in arum lily.

Key words: Arum lily, callus, culture filtrate, in vitro selection, Pectobacterium carotovorum sp. carotovorum, soft rot.