Response of wheat to a Jordanian isolate of Mediterranean cereal cyst nematode (Heterodera latipons)

Abstract

A total of 52 wheat genotypes comprising landraces of hard (durum), common bread wheat cultivars, and synthetic hexaploid wheat were evaluated for their reaction against a Jordanian isolate of the Mediterranean Cereal Cyst Nematode Heterodera latipons (MCCN). Three genotypes obtained from International Center for Agricultural Research in the Dry Areas (ICARDA), the Australian bread wheat cultivars, Drysdale, Gladius, GS50A and Silverstar, and the synthetic hexaploids, Langdon*Aus18913, Langdon*Aus18964, Langdon*Aus181-1472, Langdon*CPI-110649 and Langdon*CPI-110756 showed resistance to MCCN. Further, 19 out of the 23 Australian synthetic hexaploid genotypes were also resistant. The characterisation of Cre genes showed that the synthetic haploids, Langdon*Aus18913, Langdon*Aus18964, Aus 34262, Aus 34423 and Aus 34448 genotypes, carrying Cre3 resistant gene, expressed high levels of resistance to MCCN while the genotypes CPI133859, CPI133872, Aus 10894 and Silverstar, carrying Cre1 resistant gene, varied in their levels of resistance to MCCN and ranged from moderately susceptible to resistant. The genotype, Frame carrying Cre8 was moderately resistant. We were not able to identify those wheat genotypes carrying Cre5 or Cre8 because of the lack of reproducibility of the PCR and the poor linkage of the markers associated with resistance to the two genes. On the other hand, some commercial cultivars and improved genotypes were resistant to MCCN and do not have Cre3 or Cre1. They may possess other uncharacterised Cre genes against MCCN and thus represent potential new sources of resistance genes that could be used for wheat improvement against H. latipons.