Molecular Identification Of Pathogen Of Plantain Head Blight And Resistance Screening Of Germplasm Of Wild Plantain

Plantain (Plantago asiatica L.) is an economically important crop and special Chinese herb in Ji’an city of Jiangxi province. In recent years, plantain head blight occurs seriously in Ji’an and attracts much attention of authorities at all levels. This article dealt with studies of molecular identification of the pathogen, biological characteristics and pathogenicity difference among eight isolates of the pathogen, toxin production conditions, and wild plantain resistant germplasm screening. The results are as follows.1. Eukaryotic universal primers ITS1/ITS4 were used to amplify pathogen of plantain head blight’s rDNA ITS sequence. The amplified fragments were sequenced and compared with counterparts in GenBank. Based on sequence homology, the pathogen of plantain head blight was identified as Diaporthe angelicae.2. Plantain head blight samples were collected from different areas of Ji’an city. Eight isolates were obtained from these samples by using aseptic technique. Experiments were carried out to test their growth rate at different temperatures, pH and carbon sources. The results showed that all 8 isolates had a consistent temperature and pH growth curve, with the optimal temperature and pH were 25℃and 6.0, respectively. In the carbon experiment, most isolates grew best with maltose as carbon source, while a small number of isolates grew best with soluble starch as carbon source. Meanwhile, pathogenicity and toxin production ability test of eight isolates were conducted. The results showed that isolate DA-8 had the strongest pathogenicity, while isolate DA-6 had the strongest toxin production ability.3. Isolate DA-8 having the strongest toxin production ability was used to examine toxin-producing conditions. The results showed that the optimal cultural conditions for producing toxin were PS medium, temperature 25℃and pH 6. Illumination and culture methods didn’t have obviously impact on toxin-producing.4.175 wild plantains collected from different parts of Jiangxi were identified for their resistance to plantain head blight. Results showed that two germplasms were highly resistant, and most of the wild plantains showed highly infection.Molecular identification of the pathogen and acquisition of two resistant wild germplasms are two important achivements of this paper and also have obvious creativity. They have significant theoretical and practical value for directing further study of the disease and host resistance.