Objective We studied the fungal diversity and communities of rhizosphere soil of sorghum parent materials with different salt-resistances when grown in light saline-alkali land, aiming to understand the relationship between the fungal communities and the salt-resistance, offering a technical support for screen high quality seed resources.

Methods Ten sorghum parent materials were selected for a pot experiment, including 2 high sensitive materials (366 and 1012), 4 sensitive materials(67, 68, 473, and 35), 1 middle sensitive material (622), 1 tolerant material (342), and 2 high tolerant materials (1187 and 1090). After the sorghum materials were grown on light saline-alkali soil (EC value: 1214 mS/cm) for 15 days, rhizosphere soil samples were collected for ITS sequencing using Illumina Miseq platform. Then, Mothur software was used to analyze OUT, α-diversity, β-diversity and species structure composition of the sequencing data.

Results A total of 619544 valid sequences were obtained from rhizosphere soil of 10 sorghum parent materials, with an average length of 371.94−392.93 bp. A total of 2145 OUTs were identified, 38 of them were common in the 10 rhizosphere soils. and more OTUs were identified from the rhizosphere soil of the two high salt-tolerant materials 1187 and 1090 than from the others. The Chao1, ACE and Shannon indices of the fungal communities in the rhizosphere soils of salt-tolerant sorghum parent materials were higher while the Simpson were lower than the those in the other materials. While in rhizosphere soil of salt-sensitive materials, the Chao1, ACE and Shannon indices were lower and the Simpson were higher than the other materials. The β-diversity of fungal communities were significantly different in rhizosphere soils between salt-tolerant and salt-sensitive sorghum parent materials. At the genus level, the dominant fungal communities in rizhosphere soil of salt-tolerant sorghum materials were Phlyctochytrium, Podospora, unclassified Glomerales and unclassified Psathyrellaceae, while in the rizhosphere soil of salt-sensitive sorghum materials were unclassified Xylariaceae, Actinomucor and Fusarium. Correlation analysis indicated that the correlations among most traits reached significant or extremely significant levels. The correlation coefficient between Psathyrellaceae and bud length was 0.98**, between Phlyctochytrium and root length was 0.94**, and between Podospora and root length was 0.86**. In contrast, unclassified Xylariaceae, Actinomucor, and Fusarium showed significant negative correlations with both root length and bud length.

Conclusions When gown in light saline-alkali soil, the rhizosphere soil of salt-tolerant sorghum parent materials contains more fungal community species (mainly AMF) and had higher diversity indices than the non tolerant materials. The abundances of the fungal communities, that are positively correlated with the development and growth of roots, are higher in rhizosphere soil of salt-tolerant materials than in the salt-sensitive materials, indicating the suitable micro-environment created by the salt-tolerant sorghum materials, which, help to stimulate the nutrient absorption of root, so increasing the salt -tolerance.