马铃薯疮痂病菌在植株和田间的分布与动态分析

为探明马铃薯疮痂病菌在植株和土壤中的分布情况及种群动态变化特点,利用常规PCR和定量PCR(qPCR)技术对不同环境的马铃薯疮痂病株和田间植株不同生育期的土壤样品进行病原菌的定性定量检测.结果 表明,病田、温室盆栽和微型薯苗床中马铃薯疮痂病重度发病植株的根、匍匐茎、块茎、地上茎、叶片等组织样品均可检测到184 bp的疮...

Analysis of Streptomyces scabies distribution in plants and population dynamics in the field

The objective of this work was to analyze the distribution of Streptomyces scabies on potato plants and its population dynamics in the field. The plant samples from different growing environments, and the soil samples at different plant growth stages were collected. Two molecular techniques, regular PCR and quantitative PCR (qPCR), were used for the qualitative and quantitative analysis of the pathogens. The scab-pathogen-specific amplified band (184 bp) was detected in all diseased tissue samples including roots, stolons, tubers, stems and leaves from diseased field, greenhouse potted plants and minituber seedbeds. However, there were no such bands in the corresponding tissues of healthy plants. The qPCR detection results showed that the spore equivalents per gram of different tissue samples (diseased field/pot plants/minituber seedbed) were: leaves (7.63/8.06/20.49)×10³, stems (2.67/4.75/73.35)×10⁴, stolons (56.84/3.78/79.88)×10⁵, tubers (1.67/2.60/43.47)×10⁷, roots (2.51/51.79/8.31)×10⁵. During the different growth periods of potato in the diseased field, the spore equivalents of pathogens per gram of free soils and rhizosphere soils were (2.12-9.18)×10⁴ and (2.31-14.03)×10⁴ respectively, and the tuber swelling stage was higher than others. Further tracking by quantitative detection was conducted in order to reveal the relative amount of pathogens in different parts of diseased plants. The testing results showed that the range of spore equivalents per gram were leaves (4.62-23.76)×10³, stems (6.12-77.08)×10³, stolons (2.75-4.57)×10⁴, roots (1.41-2.36)×10⁵, tubers 3.43×10⁴-2.04×10⁷ at four stages of seedling, tuber forming, tuber swelling and harvest respectively. This study preliminarily investigated the distribution of Streptomyces scabies on potato plants and its population dynamics in the field. It laid a foundation for further study on the infection mechanism and occurrence regularity of the common scab disease.