Improved root box for quantification of newly produced cyst nematode females

Abstract

A simple root box (RB) described in a previous study for screening of nematode resistant cultivars can be used to count cyst females appearing on the RB surface as an estimate of total number of Heterodera schachtii (HS) females appearing on a root system. However, only 60% of cyst females can be seen on the RB surface because other females on roots are obscured by soil. Another disadvantage is the two RB surfaces, front and back, must be examined when counting nematodes. To overcome these shortcomings, an improved sheet root box (SRB) with a nylon mesh sheet (30 µm openings) placed between the soil and the SRB surface was proposed to observe most of the females parasitizing a root system. The roots of a test plant are prevented from growing in soil by a nylon mesh sheet but grow in the space between the sheet and the SRB surface. In this study, it was confirmed that the root system of a host plant developed only on the sheet with no roots growing into soil behind the sheet, thus nematodes appeared only on one SRB surface. The number of nematodes on the SRB surface was similar to the number on the entire root system. More than 90% of the nematodes present on the entire root system were visible on the sheet surface. SRB would allow more precise and efficient quantification of HS females appearing on root systems in inoculation tests.