小麦叶锈病是危害小麦最严重的病害之一，该病由小麦叶锈菌（Puccinia recondite f. sp. tritici）引起，侵染小麦叶片，严重影响小麦光合作用从而造成减产，培育和利用小麦抗叶锈病品种是最为经济有效的防治措施。为鉴定国内外普通小麦材料中所携带的抗病基因并了解其组成背景，发掘新的抗叶锈病基因，本研究结合基因推导、分子标记检测等方法对66个来自世界不同国家的普通小麦品种（系）进行了抗叶锈病基因鉴定。在苗期接种17个不同毒力的小麦叶锈菌生理小种，通过与36个含有单个已知抗病基因的载体品种抗性比较进行基因推导。同时，利用12个与已知抗病基因紧密连锁的分子标记对供试品种（系）进行基因标记检测，以验证基因推导结果。在河南周口（2016-2017年度）、河北保定（2017-2018年度）两地对66个供试品种（系）进行小麦叶锈病田间叶锈抗性调查，利用SAS软件对鉴定数据进行分析，以筛选出具有成株慢锈性的品种。结果表明，在66个供试品种（系）中，12个品种（系）含有Lr1，4个品种（系）含有Lr26，3个品种含有Lr10，2个品种含有Lr20，2个品种含有Lr17。通过成株抗病基因分子标记检测发现，14个品种（系）含有Lr34，5个品种含有Lr46，3个品种（系）含有Lr37。结合田间调查结果发现，有17个品种（系）具有成株慢锈性。这些含有已知抗病基因的品种及慢锈性品种将丰富我国现有的小麦种质资源，有利于培育抗病品种，同时为利用基因布局防治小麦叶锈病提供遗传学依据。

Wheat leaf rust is a destructive foliar disease of common wheat (Triticum aestivum L.) worldwide. The most effective, economical s to control the disease is growing resistant cultivars with adult plant resistance (APR). The Chinese wheat lines W014204 and Fuyu 3 showed high leaf rust resistance in the field. To identify leaf rust APR genes in the two lines, two mapping populations with 215 and 163 F2:3 lines from the crosses W014204/Zhengzhou 5389 and Fuyu 3/Zhengzhou 5389, respectively, were phenotyped for leaf rust severities during the 2010–2011, 2011–2012 and 2012–2013 cropping seasons in the field at Baoding, Hebei Province, China. A total of 1 215 SSR markers were used to identify the quantitative trait loci (QTLs) for leaf rust APR in the two populations. In the W014204/Zhengzhou 5389 population, three QTLs were detected and designated as QLr.hbu-1BL.1, QLr.hbu-2BS.1 and QLr.hbu-7DS, and explained 2.9–8.4, 11.5–38.3 and 8.5–44.5% of the phenotypic variance, respectively; all the resistance alleles at these loci were derived from W014204. In the Fuyu 3/Zhengzhou 5389 population, three QTLs, QLr.hbu-1BL.2, QLr.hbu-2BS.2 and QLr.hbu-7BL, explained 12.0–19.2, 22.3–38.9 and 4.1–4.3% of the phenotypic variance, respectively, and all resistance alleles were contributed by Fuyu 3. Based on chromosome positions of closely linked markers, both QLr.hbu-1BL.1 and QLr.hbu-1BL.2 are Lr46, and QLr.hbu-7DS is Lr34. QLr.hbu-7BL was mapped on chromosome 7BL near to Lr68 and they are likely the same gene. Based on chromosome positions, pedigree and field reactions, the two 2BS QTLs are different from all the known APR genes and are likely to be new APR QTL for leaf rust. These QTLs and their closely linked markers are potentially useful for improving leaf rust resistance in wheat breeding.

Proteomic assessment of low-abundance leaf proteins is hindered by the large quantity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) present within plant leaf tissues. In the present study, total proteins were extracted from wheat (Triticum aestivum L.) leaves by a conventional trichloroacetic acid (TCA)/acetone method and a protocol first developed in this work. Phytate/Ca2+ fractionation and TCA/acetone precipitation were combined to design an improved TCA/acetone method. The extracted proteins were analysed by two-dimensional gel electrophoresis (2-DE). The resulting 2-DE images were compared to reveal major differences. The results showed that large quantities of Rubisco were deleted from wheat leaf proteins prepared by the improved method. As many as (758±4) protein spots were detected from 2-DE images of protein extracts obtained by the improved method, 130 more than those detected by the TCA/acetone method. Further analysis indicated that more protein spots could be detected at regions of pI 4.00-4.99 and 6.50-7.00 in the improved method-based 2-DE images. Our findings indicated that the improved method is an efficient protein preparation protocol for separating low-abundance proteins in wheat leaf tissues by 2-DE analysis. The proposed protocol is simple, fast, inexpensive and also applicable to protein preparations of other plants.

In recent years, subgroup J avian leukosis virus (ALV-J) has been found to frequently infect layers in China. This virus is responsible for economic losses due to both mortality and decreased performance in chickens. In this study, 45-d-old cloned free-range layers were suspected to be infected with ALV and other immunosuppressive diseases because their feathers were unkempt and their growth rate was impaired. To estimate the infection status and determine the source of ALV-J in the flock, 30 cloacal swabs were randomly collected to measure the p27 antigen level by enzyme-linked immunosorbent assay (ELISA). Among the birds that were tested, 87% (26/30) were positive. In addition, 6 anticoagulant blood samples were aseptically collected at random from the flock when the layers were 60 d old. These samples were centrifuged to obtain the leukocytes, which were then used to inoculate chicken embryo fibroblast (CEF) cells for the identification of ALV-J by indirect immunofluorescence (IFA). Of the samples tested, 100% (6/6) were positive. The flock’s production performance was also investigated, and 10 layers were necropsied to evaluate pathological changes at 115 d of age. The flock never laid eggs even though they reached the age of the first laying (110 d). Furthermore, there were pathological changes present, including atrophy of the thymus and bursa of Fabricius, undeveloped ovaries, glandular stomach haemorrhage, and hepatosplenomegaly. Paraffin-embedded sections of intumescent liver and spleen were prepared for antigen localisation using IFA. Positive signals were prevalent in paraffin-embedded sections of the intumescent liver and spleen. Furthermore, provirus DNA was extracted from 4 cloned free-range layers, and 2 paternal parents (HR native cocks), and the gp85 gene of ALV-J was amplified by PCR to analyse the genetic variation. The results of the autogenous variation analysis showed that the 6 strains were 98.5-99.7% homologous. This study indicated that there was persistent infection with ALV-J by dynamic inspection, which seriously reduced the production performance of the flock. In addition, the genetic variation analysis showed that ALV-J in the flock was more likely to have originated from the paternal parent, the HR native cock.