Abstract:

Mycorrhizal dependency was studied in 23 wild emmer (Triticum turgidum subsp. dicoccoides) accessions originating from ecologically and geographically different locations in the Fertile Crescent covering Israel, Turkey, Lebanon, Jordan, and Syria. Wild emmer accessions were grown with mycorrhizae (Glomus mosseae) and non-mycorrhizae under greenhouse conditions, and harvested according to the Zadoks scale at growth stage 33. Root, shoot and total dry weight, growth response, root infection, and mycorrhizal dependency were calculated. It was determined that mycorrhizal inoculation increased 4.1-, 3.9-, and 3.9-fold for root, shoot, and total dry weight, respectively, compared to the control. It was found that wild emmer wheat exhibited a wide range of mycorrhizal dependency (56.8%-90.5%) and growth response (144.0%-990.4%), except root colonisation (70.0%-75.0%). Based on these observations, the hypothesis whether or not wild wheat chromosomes have a gene(s) for mycorrhizal response was tested. The experiment was done on the Langdon-T. dicoccoides substitution lines, each having an individual chromosome from "wild emmer wheat", T. dicoccoides, substituted into the tetraploid wheat cultivar "Langdon" background. Among the Langdon-T. dicoccoides substitution lines, mycorrhizal dependency and growth response varied from 70.9% to 87.0% and from 261.1% to 690.0%, respectively, whereas most of the substitution lines were significantly lower than Langdon for these traits. Disomic substitution lines for B genome chromosomes of dicoccoides showed a significant reduction in mycorrhizal dependency and growth response when compared with disomic substitution lines for A genome chromosomes of dicoccoides. These results revealed that B genome chromosomes had a more detrimental effect on mycorrhizal dependency than did A genome chromosomes. The results of this study showed that wild emmer wheat may be used as a source of mycorrhizal dependency in wheat breeding.

Keywords: