Screening for resistance in the primary and secondary gene pool of barley against the root‐lesion nematode Pratylenchus neglectus

Abstract

Root‐lesion nematodes of the genus Pratylenchus are significant pests in crop cultivation throughout many parts of the world. A study was initiated to determine the resistance of Hordeum vulgare and H. vulgare ssp. spontaneum (wild barley) against one major representative of the genus Pratylenchus, P. neglectus. A glasshouse test was first established. Barley seedlings were grown in 20 cm3 tubes filled with sand. Each plant was inoculated with 400 P. neglectus juveniles. After 12 weeks of cultivation nematodes were isolated from roots and sand using a misting chamber. The nematodes were counted under a microscope. A representative collection of 565 barley and wild barley accessions was tested in this way. The average number of nematodes per accession ranged from 350 to 12 000. In a verification experiment, 35 accessions with low and high infection rates were tested. This experiment identified a number of accessions with low infection rates. The perspectives for future breeding of barley cultivars resistant to root‐lesion nematodes are discussed.

Screening of barley germplasm for resistance to root lesion nematodes

“…Each seedling was placed in a 20 cm 3 tube (12 cm ( H ) height × 2 cm (∅) thickness 2.3 mm) filled with steam-sterilized sand. Seedlings were inoculated with 400 P. neglectus juveniles in 1 ml water medium after 10 d. Further steps were followed as described in Keil et al (2009). After 12 weeks, the plants were uprooted and nematodes were extracted from the sand and the roots were chopped using a Baermann funnel placed in a misting chamber for 5 d. Nematode suspension were collected in a bottle and placed at 5°C before counting.…”

“…In the first phase of this project, screening of a large collection of barley germplasm was carried out. Five hundred and sixty-five barley accessions encompassing cultivated ( Hordeum vulgare ) and wild species ( H. spontaneum ) were screened for resistance against P. neglectus (Keil et al , 2009). In the second part, a biparental DH mapping population was used to map QTLs.…”

Evaluation of Turkish wild Emmers (Triticum dicoccoides Koern.) and wheat varieties cultivars for resistance to the root lesion nematodes (Pratylenchus thornei and Pratylenchus neglectus)

“…The number of nematodes per plant is an appropriate estimate of plant resistance (Keil et al, 2009;Sheedy et al, 2009;Farsi et al, 1995;Toktay et al, 2012b). The Reproduction factor (Rf) generally used in resistance experiments in nematology were used to give quantitative value of resistance (Keil et al, 2009).…”

“…The Reproduction factor (Rf) generally used in resistance experiments in nematology were used to give quantitative value of resistance (Keil et al, 2009). In the screening experiments under the laboratory conditions, nematode initial population (Pi ) set as inoculum level and nematode final population (Pf ) and Pf / Pi which defined as the reproduction factor of nematodes should be carefully emphasise to identify resistant reaction of the germplasm (Toktay et al, 2012b).…”

“…Resistance was evaluated from the reproduction factor calculated by dividing the final by the initial P. thornei numbers in soil plus roots (Sheedy et al, 2009;Keil et al, 2009). Data were also analyzed by ANOVA and means were separated using Duncan's Multiple Range Test at P < 0.05 significance level.…”