马铃薯卷叶病毒属病毒在世界范围内广泛分布，能够侵染多种经济作物引起严重病害。芸薹黄化病毒（Brassica yellows virus, BrYV）是在我国鉴定出的一种马铃薯卷叶病毒属的新病毒，主要侵染十字花科作物。该病毒主要包含三种基因型，分别为A、B和C，目前关于该种病毒在我国的发生分布情况尚不清楚，本研究主要对芸薹黄化病毒三种基因型在我国十字花科作物上的发生分布情况进行调查。2014-2018年，对采自我国29个省（自治区、直辖市）的570份十字花科作物的样品进行RT-PCR检测。结果表明：共有97份样品检测到BrYV侵染，病毒平均发生率为17.0%。共有22个省（自治区、直辖市）的样品中检测到BrYV的侵染，其中在我国的华北地区、西北地区和东北地区有相对较高的病毒发生率。进一步利用多重RT-PCR检测方法对BrYV的三种基因型进行检测，在97份BrYV侵染的样品中：61.9%的样品受单种基因型的侵染，29.9%的样品受两种基因型的复合侵染，8.2%的样品受三种基因型的复合侵染；A、B和C三种基因型的检出率分别为39.2%、40.2%和67.0%。以上研究表明，BrYV在我国的十字花科作物上发生分布比较普遍，北方地区要比南方地区各省病毒发生率高。BrYV发生存在单基因型侵染和多种基因型复合侵染的现象，C基因型具有相对较高的发生率，为优势基因型。并且本研究还发现BrYV与其它两种蚜传病毒芜菁花叶病毒(Turnip mosaic virus, TuMV)和黄瓜花叶病毒(Cucumber mosaic virus, CMV)在十字花科作物上普遍发生复合侵染的现象。本研究首次对BrYV在我国的十字花科作物上的发生分布情况展开大量调查，研究结果将有助于该病毒病害的有效防控。

Poor soil structure and nutrients, excessive exchangeable Na⁺, high pH as well as low enzyme activities are common in the solonetz, and significantly restrict corn (Zea mays L.) production. Cattle manure application combined with deep tillage is an important management practice that can affect soil physico-chemical properties and enzyme activities as well as corn yield in the solonetz. Field experiments were carried out in a randomized complete block design comprising four treatments: Corn with conventional tillage was used as a control, and corn with manure application combined with deep tillage as well as film mulching and aluminium sulfate were used as the experimental treatments, respectively. The relationship between corn yield and measured soil properties was determined using stepwise regression analysis. Manure application combined with deep tillage management was more effective than conventional tillage for increasing corn yield and for improving soil properties in the solonetz. The highest corn yield was obtained in the treatments with manure application+deep tillage+plastic film mulching (11 472 and 12 228 kg ha^–1), and increased by 38 and 43% comparing with the control treatment (8 343 and 8 552 kg ha^–1) both in the 2013 and 2014 experiments, respectively. Using factor analysis, three factors were obtained, which represented soil fertility status, soil saline-alkaline properties and soil structural properties both in the 2013 and 2014 experiments, respectively. Manure and deep tillage management resulted in two distinct groups of soil properties: (1) soils with manure application combined with deep tillage and (2) soils with conventional tillage. Stepwise regression analysis showed that corn yield was significantly and positively correlated to urease and available P, as well as negatively correlated to pH, electrical conductivity (EC), exchange sodium percentage (ESP), and bulk density (ρ_b). We concluded that ρb was dominant factor for corn yield on the basis of discriminant coefficient. Manure application combined with deep tillage management resulted in an increase in corn yield mainly owing to improved soil structural properties, followed by decreased soil saline-alkaline obstacle as well as increased urease activity and available P. This result is likely that the improvement in soil organic matter (SOM) from manure application greatly and positively contributed to better soil physico-chemical properties and enzyme activities, especially decrease in ρ_b. Suggestion for corn production should be improvement in soil structural properties firstly. This could cause decrease in ρ_b that key factor which limited the corn production in the solonetz.