Welcome to Chinese Journal of Biological Control,Today is

journal1 ›› 2017, Vol. 33 ›› Issue (1): 94-102.DOI: 10.16409/j.cnki.2095-039x.2017.01.014

Previous Articles     Next Articles

Screening Efficient Trichoderma Engineering Strain against Tomato Damping-off by Protoplast Fusion

CHEN Kai, LI Jishun, LI Ling, WEI Yanli, WANG Yilian, HU Jindong, ZHAO Zhongjuan, YANG Hetong   

  1. Shandong Provincial Key Laboratory of Applied Microbiology/Ecology Institute of Shandong Academy of Sciences, Jinan 250014, China
  • Received:2016-08-02 Online:2017-02-08 Published:2017-01-24

Abstract: By thermal and ultraviolet inactivated protoplast fusion, efficient Trichoderma fusant against tomato damping-off were screened. The protoplasts of T. harzianum TW21990 and Trichoderma sp. TW21990-1 were inactivated by thermal and ultraviolet treatment, respectively, and protoplast fusion with PTC (as fluxing agent) was conducted on inactivated protoplast. Thirty-one fusants were obtained and the fusion rate reached to 10.5%. Based on morphological characteristics, all the fusants could be divided into three types, some fusants similar to parents TW21990 or TW21990-1, while other fusants showing an intermediate morphological phenotype. Gray correlative degree analysis showed that biocontrol characters of nine Trichoderma fusants were superior to the parents, and fusant Tpf-2 was the best one. Random amplified polymorphic DNA (RAPD) analysis and biological character detection showed that different fusants had different relationship with parents, and there were diversity among them. The same fusant had inheritable stability after ten generations. Morphological identification was consistent with UPGMA analysis of RAPD. The control efficiencies of fusant Tpf-2 were 86.3% and 85.7% against tomato damping-off caused by Pythium aphanidermatum and P. ultimum, respectively, significantly higher than those of the parents (P<0.01). Due to its inheritable stability and superior biocontrol characters, fusant Tpf-2 is a promising candidate for the control of tomato damping-off.

Key words: Trichoderma spp., protoplast fusion, grey relational degree, RAPD, tomato damping-off

CLC Number: