Breeding for Enhanced AMF-Wheat Compatability.

Most plant roots naturally form a symbiosis with arbuscular mycorrhizal fungi (AMF).  These AMF associations with plant roots enhance absorption, improving plant nutrient uptake and health. Durum genotypes selected for AMF symbiotic effectiveness may use soil nutrients more effectively than current cultivars. Selection for ‘symbiotic compatibility traits' requires the presence of variation in wheat genotypes. The purpose of this study was to investigate variation in durum wheat for compatibility with AMF. Experiments involved five genotypes selected from a collection of durum genotypes from Canada and worldwide that represented distinct population groups as determined by relationship analysis using simple sequence repeat marker evaluation. These genotypes were inoculated with live Glomus intraradices formulated as Myke Pro PS3 or with sterilized inoculants as a control. Two greenhouse experiments were conducted. The first experiment was conducted under low soil fertility conditions and the second experiment was conducted under conditions of medium soil fertility. Mineral content of plant and seed tissues was measured. The level of compatibility was determined by scoring root colonization by AMF. We discovered that the roots of different durum wheat genotypes developed AMF symbioses to different extents and that durum wheat genotypes varied in their biomass and nutrient uptake in response to the AMF symbiosis. The roots of genotype DT710 developed the most extensive AMF colonization. Commander expressed the most extreme difference in root colonization between soils of low and medium fertility. AC Morse and Mongibello showed the least differences among the two soil levels of soil fertility. There was no growth response to the AMF symbioses under conditions of low soil fertility, but under conditions of medium soil fertility, Mongibello produced more grain and total biomass. The live mycorrhizal treatment produced higher grain manganese concentration and reduced grain cadmium concentration compared to the non-mycorrhizal control. The phenotypic variation observed in these experiments indicates potential for breeding for better AMF symbiosis in durum wheat. Ability to rapidly screen for AMF compatibility is essential for quicker selection and integration of this trait in elite germplasm.