Sampling strategies for sensitive, accurate and cost effective detections of Phylloxera for quantifying area freedom status

Abstract

A rapid, cost-effective and accurate soil sample protocol for detection of phylloxera by quantitative PCR (qPCR) was developed. Composite soil samples collected in a grid pattern should be handled and transported to avoid heating above 20°C, reach the laboratory within 48 hours of collection and dried within 24-48 hours, to limit phylloxera DNA degradation. Detection limit of qPCR was estimated at 1.5 to 2 phylloxera per 200g dry soil. Highest phylloxera detection rate and numbers were obtained with samples taken 0-10cm deep and as close to the vine trunk as possible (within 10cm), and higher numbers were consistently found from mid-summer to early winter.

Summary

A rapid, cost-effective and accurate soil sample protocol for detection of phylloxera by quantitative PCR (qPCR) was developed. Composite soil samples collected in a grid pattern should be handled and transported to avoid heating above 20°C, reach the laboratory within 48 hours of collection and dried within 24-48 hours, to limit phylloxera DNA degradation. Detection limit of qPCR was estimated at 1.5 to 2 phylloxera per 200g dry soil. Highest phylloxera detection rate and numbers were obtained with samples taken 0-10cm deep and as close to the vine trunk as possible (within 10cm), and higher numbers were consistently found from mid-summer to early winter.