Bacterial Isolates from Root Nodules of Zygophyllaceæ

Global database of plants with root‐symbiotic nitrogen fixation: NodDB

“…Nodulation was first observed for the genus Tribulus > 100 years ago (Isachenko, ), but received limited attention for three decades. Nodulation and growth benefits were later confirmed for the Zygophyllaceae genera Fagonia, Larrea, Tribulus and Zygophyllum (Sabet, ; Mostafa & Mahmoud, ; Athar & Mahmood, ; Medan & Tortosa, ), often accompanied with convincing illustrations about nodule morphology. It has remained unclear whether Zygophyllaceae associate with rhizobia, cyanobacteria or a variety of groups.…”

“…Using electron microscopy, Mahmood and Athar (, ) described abundant cells belonging to both Rhizobiaceae and cyanobacteria in nodules of Tribulus terrestris, whereas only Rhizobiaceae spp. were described from multiple zygophyllaceous taxa previously (Sabet, ; Mostafa & Mahmoud, ). However, in Zygophyllum fabago nodules collected from Iran, we consistently detected abundant Vibrio sp.…”

“…Although Jenkins et al. () found low nodulation capacity of soil from L. tridentata in roots of a legume Prosopis sp., the poor nodulation can be ascribed to partner specificity of symbiotic rhizobia (Mostafa & Mahmoud, ; Bala & Giller, ). In another study, Demba Diallo et al.…”

“…A small genus Parasponia (Cannabaceae) has evolved independently symbiotic associations with Rhizobiaceae (Trinick, ). In addition, rhizobial root nodules have been reported in three zygophyllaceous genera, Tribulus , Fagonia and Zygophyllum (Mostafa & Mahmoud, ), but this family has received limited attention in recent treatments in spite of mono‐dominance of some species in desert habitats around the world (Sheahan, ). Frankiaceae (Actinobacteria) form actinorhizal root nodules with genera from multiple eurosid plant families (Chaia, Wall, & Huss‐Danell, ).…”

Plant-endophyte symbiosis in non-leguminous plants

“…In this fainily of xerophytic shrubs and herbs, soine species of the poor sandy soils of the Egyptian desert bear root nodules and there are claiins that their growth in nitrogen-deficient soll is thrifty, provided nodules are present (Mostafa and Mahmoud, 1951;Sabet, 1946). However, this is still a Inatter of controversy as Allen and Allen (1950) found no evidence of an endophyte in a cytological study of Tribulus cistoides root nodules and they suggest that these structures are starchstorage organs.…”