Investigation of resistance to Pratylenchus penetrans and P. thornei in international wheat lines and its durability when inoculated together with the cereal cyst nematode Heterodera avenae , using qPCR for nematode quantification uri icon

abstract

  • The root lesion nematodes Pratylenchus penetrans and P. thornei cause high yield losses in rain-fed wheat fields in Morocco, as well as worldwide. Growing resistant varieties is one of the most effective methods for controlling nematodes. Therefore, a collection of 14 lines of spring wheat and 11 lines of winter wheat (Triticum aestivum and T. durum), provided by CIMMYT, were screened for resistance to P. penetrans and P. thornei in tubes (15 x 20 x 120 mm(3)) under greenhouse conditions. The resistance level was evaluated based on the numbers of nematodes extracted from roots and soil 9 weeks after infestation. Three lines (L9, L12 and L13) were found moderately resistant (reproduction factor < 1) to P. thornei and one of these (L9) was also moderately resistant to P. penetrans. To investigate the durability of this resistance, we co-inoculated juveniles of Heterodera avenae, a cereal cyst nematode widely present in Moroccan wheat fields, and assessed the reproduction of both lesion nematodes on the three lines. Our results showed that the lines L9, L12, L13 remained moderately resistant in the presence of H. avenae. Moreover, the numbers of Pratylenchus spp. were generally lower when plants were co-inoculated with H. avenae. The number of P. penetrans or P. thornei were determined visually using a microscope and with a qPCR assay. The counts with qPCR were even lower than microscopic counts. These findings on resistance are promising but the field performance of these lines against root lesion nematode attacks should be evaluated.

publication date

  • 2018
  • 2018