This study was designed to identify molecular markers single nucleotide polymorphisms (SNPs) of MHC B-F gene and SPOCK1) associated with Salmonella pullorum disease susceptibility/resistance. A two-stage case-control association study was used. In the first study, a small population comprising 401 Partridge chickens (201 cases and 200 controls) was used, and a total of 118 SNPs genotyped. In the second study, a bigger population comprising 1 075 Partridge chickens (527 cases and 548 controls) was used, and SNPs with significant effect determined in the first study were further analysed. In the first study, 8 SNPs were significantly associated with S. Pullorum disease susceptibility/resistance, however, after further analysis, only the SNPs rs15001532 and C.513A>T were found to be significantly associated with S. Pullorum disease susceptibility/resistance. The relative risk test demonstrated that the AA genotype of rs15001532 resulted in a higher risk of S. Pullorum infection, whereas birds with the TT genotype of C.513A>T were more susceptible to S. Pullorum infection. This research was based on the researches on human complex diseases. With help of these train of thoughts, some common animal diseases can be studied effectively and the process of candidate gene research for animal disease can be improved.

Collapsing gully erosion is a specific form of soil erosion types in the hilly granitic region of tropical and subtropical South China, and can result in extremely rapid water and soil loss. Knowledge of the soil physical and chemical properties of farmland influenced by collapsing gully erosion is important in understanding the development of soil quality. This study was conducted at the Wuli Watershed of the Tongcheng County, south of Hubei Province, China. The aim is to investigate soil physical and chemical properties of three soil layers (0–20, 20–40 and 40–60 cm) for two farmland types (paddy field and upland field) in three regions influenced by collapsing gully erosion. The three regions are described as follows: strongly influenced region (SIR), weakly influenced region (WIR) and non-influenced region (NIR). The results show that collapsing gully erosion significantly increased the soil gravel and sand content in paddy and upland fields, especially the surface soil in the SIR and WIR. In the 0–20 cm layer of the paddy field, the highest gravel content (250.94 g kg^–1) was in the SIR and the lowest (78.67 g kg^–1) was in the NIR, but in the upland filed, the surface soil (0–20 cm) of the SIR and the 40–60 cm soil layer for the NIR had the highest (177.13 g kg^–1) and the lowest (59.96 g kg^–1) values of gravel content, respectively. The distribution of gravel and sand decreased with depth in the three influenced regions, but silt and clay showed the inverse change. In the paddy field, the average of sand content decreased from 58.6 (in the SIR) to 49.0% (in the NIR), but the silt content was in a reverse order, increasing from 27.9 to 36.9%, and the average of the clay content of three regions showed no significant variation (P<0.05). But in the upland filed, the sand, silt and clay fluctuated in the NIR and the WIR. Soils in the paddy and upland field were highly acidic (pH<5.2) in the SIR and WIR; moreover lower nutrient contents (soil organic matter (SOM), total N and available N, P, K) existed in the SIR. In the 0–20 cm soil layer of the paddy field, compared with the NIR and the WIR, collapsing gully erosion caused a very sharp decrease in the SOM and total N of the SIR (5.23 and 0.56 g kg^–1, respectively). But in the surface soil (0–20 cm) of the upland field, the highest SOM, total N, available N, available P and available K occurred in the NIR, and the lowest ones were in the SIR. Compared with the NIR, the cation exchange capacity (CEC) in the SIR and WIR was found to be relatively lower. These results suggest that collapsing gully erosion seriously affect the soil physical and chemical properties of farmland, lead to coarse particles accumulation in the field and decrease pH and nutrient levels.