大豆胞囊线虫主效抗病基因Rhg4(GmSHMT)的CAPS/dCAPS标记开发和利用

大豆胞囊线虫(soybean cyst nematode,SCN)严重危害世界大豆生产,Rhg4(resistance to Heterodera glycines 4)是控制大豆SCN抗性的2个主效位点之一。本研究针对Rhg4(Gm SHMT)上的2个单核苷酸多态性(single nucleotide polymorphisms,SNP)位点开发了快速、经济、简便易行的CAPS(Rhg4-389)和d CAPS标记(Rhg4-1165),并用开发的2个标记鉴定了以大豆胞囊线虫应用核心种质为主的193份代表性抗感种质。结果表明,Rhg4-389和Rhg4-1165位点间存在显著连锁不平衡(P=0.0001,r2=0.87),可形成4种单倍型。Rhg4-389-G/Rhg4-1165-T和Rhg4-389-C/Rhg4-1165-A为优势单倍型,稀有单倍型Rhg4-389-G/Rhg4-1165-A和Rhg4-389-C/Rhg4-1165-T是在中国抗源中新发现的单倍型。结合193份种质对SCN 3号小种抗性鉴定分析发现,Rhg4-389-G和Rhg4-1165-T主要存在于抗病种质,它们形成的单倍型对抗病种质鉴定效率可达94.1%。本研究开发了可用于辅助大豆SCN抗性鉴定且方便育种家利用的CAPS/d CAPS标记,且用其摸清了应用核心种质等重要抗源在Rhg4位点的"本底",为育种家有效利用这些优异抗源提供了重要信息。     

Histologic features of hair follicle neoplasms and cysts in dogs and cats: a diagnostic guide

Hair follicle neoplasms occur in many different species, including humans. In domestic animals, they are most common in dogs. Most hair follicle tumors are benign, but malignant neoplasms can also occur. To diagnose hair follicle neoplasms, a thorough knowledge of follicular anatomy is important, given that follicular tumors are classified according to the differentiation pattern seen in the corresponding part of the normal hair follicle. This review focuses on the key diagnostic features of hair follicle tumors and follicular cysts in dogs and cats.     

Retrobulbar respiratory epithelial orbital cyst in a dog: A case report

A 10-month-old female, neutered French Bulldog presented with a history of unilateral right-sided intermittent conjunctivitis and exophthalmos. The patient suffered blunt force trauma to the right eye after a tennis ball impact approximately five months prior to presentation. Examination identified the patient was visual with exophthalmos, lateral strabismus, conjunctival hyperaemia, episcleral congestion, and papilloedema. Magnetic resonance imaging and ultrasonography identified an approximately two centimeter diameter fluid-filled structure directly posterior to the globe leading to displacement of the optic nerve and distortion of the posterior globe wall. Centesis of the lesion demonstrated neutrophilic and macrophagic inflammation with evidence of prior hemorrhage. Within four weeks, the structure had re-filled to its original size and was subsequently excised in its entirety, via a lateral orbitotomy. Histopathologic findings indicated a non-keratinising orbital cyst, the lining of which was consistent with a respiratory epithelial cyst. Recurrence had not occurred seven months' post-surgery. To the author's knowledge, previous reports of retrobulbar respiratory epithelial cysts have not been documented in animals.     

Identification and resistant characterization of legume sources against Meloidogyne incognita

Root-knot nematodes(RKNs; Meloidogyne spp.) are becoming a serious problem in legume production. This study identified Vigna genotypes exhibiting resistance to M. incognita(RKN) and characterized the modes of the resistance to M. incognita. In total, 279 accessions from 21 Vigna species were screened for resistance based on a galling index(GI) and an egg mass index(EI). Seven accessions were highly resistant to RKN with GI≤25, namely JP74716(V. mungo var. mungo; cultivated black gram), JP107881(V. nepalensis), JP229392(V. radiata var. sublobata; wild mungbean), Aus TRCF118141(V. unguiculata subsp. unguiculata; cultivated cowpea), Aus TRCF306385(V. unguiculata subsp. unguiculata), Aus TRCF322090(V. vexillata var. vexillata; wild zombi pea) and JP235929(V. vexillata var. vexillata). JP229392 and Aus TRCF322090 were the most resistant accessions having EI values of 18.74 and 1.88, respectively. Continuous culture of M. incognita on both JP229392 and Aus TRCF322090 resulted in a weakness in pathogenic ability for this RKN. The resistance in JP229392 and Aus TRCF322090 to RKN appeared to be antibiosis that was associated with reduced nematode penetration, retardation of nematode development and impeding giant cell formation. The Vigna germplasm resistance to RKN identified in this study could be utilized as gene sources for the development of RKN-resistant Vigna cultivars.     

沼液淹没土壤抑制根结线虫及对土壤线虫群落的影响

为探索沼液抑制根结线虫的效果,本研究通过盆栽试验,以番茄为试供作物,对比了种植前沼液淹没土壤(BSS)、种植期间浇灌沼液(BS)和加热(HE)3种方法对根结线虫的防控效果。结果表明,与不采取任何措施的对照(CK)处理相比, BSS处理抑制根结线虫效果最为明显,防效高达97.1%,根结指数分别比HE和BS处理降低96.9%和92.9%。HE处理尽管在处理土壤后显著降低了根结线虫数量,但在最后破坏性取样时(结束试验)出现反弹,根结线虫数量甚至高于CK处理。对于土壤线虫群落,CK处理中以植食性线虫为主(81.8%);两个沼液处理中食细菌线虫占优势(平均78.3%),且其中的杂食捕食性线虫在土壤前处理后消失,在试验结束时又重新出现,但所占比例依然非常低。沼液淹水方式的高效防控效果揭示了利用沼液防控根结线虫的关键期在于线虫入侵到植物根部之前的幼虫期。然而,在盆栽系统中,沼液淹水的方式也对作物生长表现出了一定的抑制趋势。高量沼液施用防控病害的同时引发的植物毒害作用以及环境污染风险,需要进一步开展田间研究。     

水肥耦合对香蕉园土壤线虫群落结构及多样性的影响

以海南香蕉种植区为例,研究了水肥一体化条件下,不同水肥用量（低肥：每株香蕉施尿素400 g、磷酸二氢钾256 g、氯化钾1024 g;高肥：每株香蕉施尿素500 g、磷酸二氢钾320 g、氯化钾1280 g;低水：3800 L/株,高水：4750 L/株）对土壤线虫群落结构及多样性的影响。4个取样时期低肥低水（A）、低肥高水（B）、高肥低水（C）和高肥高水（D）4个处理的线虫总数、食细菌线虫数量、食真菌线虫数量、植物寄生线虫数量和捕食/杂食线虫数量均存在显著差异（P＜0.01）。本试验田中共鉴定出土壤线虫22科34属,其中巴兹尔属（Basiria）和针属（Paratylenchus）为优势属。单增加施肥量显著增加了植物寄生线虫数量和捕食/杂食线虫数量,同时增加施肥量和灌水量显著增加了线虫总数、食细菌线虫数量和食真菌线虫数量。从整个生育期来看,线虫总数和4个线虫营养类群的数量在苗期均较低,抽蕾期和成熟期均较高。4个取样时期A、B、C和D4个处理的多样性指数（Shannon diversity,H′）、自由生活线虫成熟度指数（Maturity index,MI）、通道指数（Channel ratio,NCR）、Wasilewska指数（Wasilewska index,WI）和富集指数（Enrichment index,EI）均存在显著差异（P＜0.01）。单增加灌水量显著增加了结构指数（Structure index,SI）和EI指数,单增加施肥量显著增加了H′和NCR指数,同时增加施肥量和灌水量显著增加了植物寄生线虫成熟度指数（plant parasite index,PPI）。从整个生育期来看,苗期的H′、NCR、SI和EI指数较高,营养生长期的MI和WI指数较高,抽蕾期的优势度指数（dominance index,λ）较高,成熟期的PPI指数较高。该研究结果表明,土壤线虫群落结构的变化很好地反映土壤水肥的变化状况,土壤线虫可作为施肥和灌溉过程中土壤质量变化的生物学指标。     

Strip-till as a means of decreasing spatial variability of winter barley within a field scale

The tillage system, which joins soil tillage, fertilisation, and seed sowing in one pass of a machine, is rarely used in cereal cultivation. This research aimed to study whether strip-till and conventional tillage (post-harvest ripping and mixing of stubble, ploughing, pre-sowing fertilisation, and seedbed preparation) differ in plant density, yield components, and grain yield of winter barley cultivated on Cambisol in a region with low rainfall, the annual average is about 500?mm. To reach this aim, a two-year, large-plot experiment was conducted in a production field. The soil within the field was spatially variable in texture, moisture, and chemical and biological properties, CV 2.3% do 29.6%. Strip-till had lower within-field spatial variability of winter barley grain yield than conventional tillage. The standard deviation was 0.36?t?ha^?1, 0.67?t?ha^?1 in the first year and 0.12?t?ha^?1, 0.30?t?ha^?1 in the second year, respectively. During the period of limited rainfall, strip-till had greater uniformity of plants after emergence; after the winter with low air temperature and a low amount of snow, it had greater plant density. Thus, strip-till can reduce variability of plants and their yield within a field, especially in adverse environmental conditions.     

直接干燥法测定粮食水分的条件优化

研究了影响直接干燥法测定粮食水分测定结果的因素,优化了测定条件。采用105℃恒质法对烘盒规格、烘干时间、烘盒个数及烘箱温度等参数进行比较,结果表明:高、低两种水分的小麦采用4.5 cm规格的烘盒,其烘干效果最佳;低水分小麦烘干4h后恒重,高水分小麦烘干4.5 h后恒重;烘盒个数以不超过20个为宜;95℃~110℃下测定结果的精密度差异不显著,但水分测定结果随烘箱温度增大而升高。     

A SCAR marker linked to the N gene for resistance to root knot nematodes (Meloidogyne spp.) in pepper (Capsicum annuum L.)

The root-knot nematodes (Meloidogyne spp.) are important nematode pests and cause serious diseases in pepper in the world. No molecular markers linked to the nematodes resistance N gene have been reported. In this paper, ‘Carolina Wonder’ (Capsicum annuum L.), a sweet pepper line resistant to root-knot nematode with N gene, ‘20080-5-29’ (C. annuum L.), an inbred line susceptible to root-knot nematode with good horticultural characteristics, and their F₂ progeny with 320 individuals were used as materials. Evaluation of resistance and susceptibility of parental lines, F₁ and F₂ progeny inoculated with root-knot nematodes (Meloidogyne incognita) were carried out. ‘Bulked segregant analysis’ method was used to search for polymorphic markers from 512 pairs of AFLP primers. Based on the assessment of resistance and susceptibility and polymorphism of the AFLP marker in F₂ population, the genetic linkage distance between the AFLP marker and the N gene was estimated. One AFLP marker E39/M41-339 was obtained and transferred to a SCAR marker amplifying a 315 bp DNA fragment linked to the N resistant allele and a 331 bp fragment linked to the N⁺ susceptible allele. The distance between the molecular marker and the nematodes resistance N gene is 6.3 cM. This research delivered a valuable tool for the marker assisted selection of nematodes resistance in pepper.