Application of marker‐assisted backcross to introgress Bph3, Bph14 and Bph15 into an elite indica rice variety for improving its resistance to brown planthopper

To improve brown planthopper (Nilaparvata lugens Stål; BPH) resistance of an elite indica cultivar of South China, Hemeizhan (HMZ), we applied marker‐assisted backcross (MABC) to incorporate three BPH‐resistance genes (Bph3, Bph14 and Bph15) into the genetic background of HMZ. In the third backcross (BC₃) generation, we obtained near‐isogenic lines (Bph3‐NIL, Bph14‐NIL, Bph15‐NIL and Bph14 + Bph15‐NIL) with more than 96% recovery of recurrent parent genome, and pyramided lines (Bph3 + Bph14‐PYL, Bph3 + Bph15‐PYL and Bph3 + Bph14 + Bph15‐PYL) with more than 89% recovery of recurrent parent genome. These lines showed stronger resistance against BPH than HMZ at seedling and booting stages. The rank of resistance gene effect was Bph3 + Bph14 + Bph15 ≥ Bph3 + Bph15 ≥ Bph3 +Bph14 ≥ Bph14 + Bph15 ≥ Bph3 ≥ Bph15 ≥ Bph14 > none. Compared with HMZ, only Bph3 + Bph14 + Bph15‐PYL had a significant difference in yield per plant, and the lines carrying Bph3 had higher amylose contents, indicating that Bph3 was tightly linked to Wx^a allele. These improved lines are good intermediate sources of broad‐spectrum and durable BPH resistance to improve other indica cultivars. Our results demonstrate that MABC is a very efficient approach to improve BPH resistance of elite rice cultivar.     

Mating type and sexual fruiting body of Botrytis elliptica,the causal agent of fire blight in lily

European Journal of Plant Pathology - Botrytis elliptica is a necrotrophic pathogen that specifically infects Lilium species. Previous records show that B. elliptica collected in the field can...     

容县乌榄叶挥发油化学成分及抗氧化活性分析

【目的】分析广西容县乌榄叶挥发油的化学成分及其抗氧化活性,为乌榄叶的药用开发提供参考。【方法】采用水蒸气蒸馏法提取广西容县乌榄叶中的挥发油,利用气相色谱—质谱联用法(GC-MS)分析其化学成分,通过峰面积归一法计算各成分的相对含量,并用DPPH·法对其抗氧化活性进行测定。【结果】容县乌榄叶挥发油共分离出55种成分,鉴定了53种,占挥发油总量的98.130%,其中单萜类化合物和倍半萜类化合物比例高,分别为20和18种;挥发油主要成分有雅槛兰-1(10),11-二烯(11.652%)、α-芹子烯(10.291%)、γ-依兰油烯(9.719%)、α-蒎烯(9.208%)和1,6-二甲基-4-异丙基-1,2,3,4,4a,7-六氢化萘(7.523%);乌榄叶挥发油质量浓度为1.2 g/L时,其对DPPH·的清除率为63%。【结论】容县乌榄叶挥发油化学成分种类较多,以单萜类化合物为主,且具有一定的抗氧化活性,可作为天然香料、抗氧化剂资源进一步研究。     

桑天牛的生物学特点及其防治技术概述

桑天牛为杨树等林木重要蛀干害虫,在我国大部分地区广泛分布,且其防治是一个世界性的难题,通过对桑天牛在生物学特性、防治方法与技术等方面的研究进展进行综述,为桑天牛的综合治理提供参考。     

Impact of 24-h Cooling Prior to Freezing on the Survival of Domestic Cat (Felis catus) Epididymal Sperm

The aim of this study was to investigate the impact of a 24-h cooling period prior to freezing on domestic cat epididymal sperm viability. Fifteen tomcats were submitted to routine orchiectomy and sperm samples were retrieved from both epididymides in a Tris–glucose–20% egg yolk extender. For each tomcat, the diluted sperm was split into two equal volumes and cooled to 5°C at a rate of 0.5°C/min; one sample for 60 min (control) and the other for 24 h (cooled). After the cooling period, samples from both groups were frozen using an identical freezing protocol. Sperm samples were evaluated in three different periods: immediately after harvesting, after cooling at 5°C for 24 h (cooled group) and after freezing–thawing of control and cooled groups. Evaluations consisted of sperm motility and progressive status, sperm morphology and plasma membrane integrity (PMI) using two fluorescent probes. After cooling for 24 h, a decrease (p < 0.05) in sperm motility, progressive status and PMI was observed when compared to sperm samples immediately after collection. Comparing the results obtained after thawing, no difference (p < 0.05) was found regarding sperm motility, progressive status, PMI and sperm morphology between control and cooled groups. The results from the present study show that cooling cat epididymal spermatozoa at 5°C for 24 h prior to freezing does not lead to major damage of spermatozoa impairing the freeze–thaw process.     

Are ovine fenugreek (Trigonella foenum‐graecum) staggers and kangaroo gait of lactating ewes two clinically and pathologically similar nervous disorders?

Fenugreek staggers has occurred in sheep in Victoria, as both an acute and a chronic syndrome. Signs included quadraparesis, a high stepping fore limb gait and a 'bunny-hopping' hind limb gait. Changes consistent with acute oedema were found in the brain and spinal cord of acute cases, and Wallerian degeneration in the peripheral nerves of chronic cases. Kangaroo gait occurred in ewes in New South Wales, and the clinical signs and microscopic changes were remarkably similar to those of fenugreek staggers. Although the diet associated with each is different the causal agent may be the same.     

Surface characterization of sputter silver-coated polyester fiber

The present study concerns modification of surface of polyester fiber by magnetron sputtering using a silver (Ag) target. A detailed characterization of the silver-coated polyester fiber was investigated by scanning electron microscopy (SEM), X-ray diffraction technique (XRD) and X-ray photoelectron spectroscopy (XPS). The results revealed the remarkable changes in the surface morphology and microstructure of silver film on polyester fiber after sputtering for 10 and 30 min respectively. The SEM results showed that the silver particles were uniformly and densely deposited on the surface of polyester fiber. The XRD pattern of silver coated fabric showed that silver film is polycrystalline structure and dominated by the very strong (220) peak. Depth profiling results of silver coated fabric by XPS indicated that mainly metallic silver is existed throughout the whole depth region.     

海南省2007/2008年冬橡胶树寒害情况浅析

调查了海南省2007/2008年冬橡胶树寒害情况,从寒害的气候特点、生态类型区、品系（种）、树龄、地形、立地环境等方面对橡胶树寒害特征进行了分析,为海南的抗寒植胶、橡胶树新品种的应用积累了新的资料,并针对防寒抗灾提出建议。