2000～2006年新育成小麦品种(系)抗条锈性鉴定分析

为了明确2000～2006年新育成小麦品种(系)的抗条锈性,采用条锈菌优势小种对1 212份小麦高代品系以及339份陕西省区试小麦品种分小种进行了抗条锈性鉴定.结果表明,供试品种(系)对条锈菌优势小种CY31、CY32及Su11-14的抗病性普遍较低,新育成小麦高代品系和陕西省区试品种对三个菌系抗病的频率分别为10.43%～55.30%和8.89%～44.82%.其中,远缘杂交后代品种(系)的抗锈性较好.另外,2001～2006年在自然诱发发病情况下,陕西省小麦区试岐山点和杨凌点共292份品种,抗病品种频率分别为5.88%～50.88%和0～50.88%.     

Crown rust affects plant performance and interference ability of Italian ryegrass in the post-epidemic generation

This study investigated the effects of crown rust (caused by Puccinia coronata f.sp. lolii) in Italian ryegrass (Lolium multiflorum) on plant growth and interference ability in the post‐epidemic generation. Rust‐infected Italian ryegrass plants produced seeds with lower weights than healthy plants (on average proportionately 0·36 lower). Furthermore, the early seedling vigour of plants from rust‐infected parents was reduced by 0·50 compared with seed from healthy parents. Under disease‐free conditions in the post‐epidemic generation, mature plants from rust‐infected parents produced 0·13 less shoot dry weight, 0·15 fewer tillers, 0·11 fewer leaves and 0·25 less leaf area than plants from healthy parents. As such, the effects of crown rust in Italian ryegrass persisted for at least one post‐epidemic generation. Under rust‐infected conditions in the post‐epidemic generation, however, the difference in performance between plants from healthy and rust‐infected parents was minimal. This suggests that any advantage plants gain from having healthy parents, compared with rust‐infected parents, might be lost when the post‐epidemic generation is grown under conditions of rust infection. Irrespective of rust infection in the post‐epidemic generation, the magnitude of intra‐specific interference was greater in monocultures of Italian ryegrass from healthy parents than in those from rust‐infected parents. However, the magnitude of inter‐specific interference and the relative interference ability of plants of rust‐infected and healthy parents did not differ. The implications of these results to plant ecology are discussed.     

香蕉枯萎病菌2种细胞壁降解酶酶活性平板检测方法

以病原真菌香蕉枯萎病菌4号生理小种为材料,建立了多聚半乳糖醛酸酶和纤维素酶的平板检测方法.多聚半乳糖醛酸酶的最佳产酶和检测条件为:诱导底物为果胶,接种孢子终浓度为1×104mL-1,培养时间为3 d.37℃时检测的多聚半乳糖醛酸酶活性最大;纤维素酶的最佳产酶和检测条件为:诱导底物为羧甲基纤维素,接种孢子终浓度为1×105mL-1,培养时间为3 d,37℃时检测的纤维素酶活性最大.在此基础上,筛选已获得的香蕉枯萎病菌4号生理小种致病力减弱突变体,获得了2株多聚半乳糖醛酸酶和纤维素酶酶活性显著降低的致病突变体.     

FTIR光谱主成分分析鉴别不同产地青稞

采用傅里叶变换红外光谱技术,通过主成分分析法对3个不同产地的19份青稞(Hordeum vulgare L.var.nudum Hook.f.)种子进行了聚类分析.结果表明,3个不同产地青稞的平均红外光谱图整体上相似,借助指纹特征区域800～1 600 cm-1红外光谱,利用DPS统计软件对其进行主成分分析,其中前3个主成分累计贡献率超过99％,同时从荷栽图可知,3个主成分代表了样品在该段光谱上的主要信息,主成分空间中样品汇集成不同的类别,可基本鉴别不同产地的青稞.在某种程度上,样本分布密度稀疏,也反映了样本间的亲缘关系.该方法为无损鉴别不同产地青稞种子提供了一种简便快速的方法,可有效反映不同产地青稞种子主要化学成分的差异.     

小麦条锈菌4个流行小种的AFLP指纹分析及与小种毒性相关性的研究

目前小麦条锈菌生理小种CY29、CY31、CY32和CY33已成为我国很多小麦产区的优势流行小种,为明确这4个小种间亲缘关系及其与毒性之间的相关性,本研究采用AFLP分子标记技术,对CY29、CY31、CY32和CY33的基因组DNA进行了AFLP标记分析,并与这4个生理小种的毒性分析相比较.结果表明;AFLP分析和毒性分析各将4个生理小种分为2个类群,两者的相关系数r=0.014.4个生理小种AFLP分析遗传多样性高于毒性分析遗传多样性,生理小种间遗传相似度较高,但两者相关性极低.     

优良野生观赏植物密花树育苗技术

密花树是具有较高园林观赏价值的乡土树种。对密花树野生种源进行苗木繁育技术试验,从小苗、容器苗、大苗培育等方面分别介绍了育苗技术。为城市园林绿化提供了一种新的优质苗木。     

国产刚竹属一新变型及一新分布记录

描述了国产早竹Phyllostachys violascens(Carr.)A.et C.Riv.的1个新变型--黄皮早竹Ph.violascens(Carr.)A.et C.Riv.f.chrysoderma T.G.Chen,以秆和枝黄色,基部节间偶有绿色纵条纹而不同于原变型。同时还首次记录了金桂竹Ph.bambusoides Sieb.et Zucc.f.holochrysa(Pfitzer)Muroi在我国的分布。     

Characterization and Molecular Mapping of a Stripe Rust Resistance Gene in Synthetic Wheat CI110

Stripe rust,caused by Puccinia striiformis f.sp.tritici (Pst),is one of the most destructive diseases of wheat (Triticum aestivum L.).To diversify stripe rust-resistant resources for wheat breeding pro...     

Binding of κ-Conotoxin-PVIIA to Open and Closed Shaker K-Channels Are Differentially Affected by the Ionic Strength

κ-Conotoxin-PVIIA (κ-PVIIA) is a potassium-channel blocking peptide from the venom of the fish-hunting snail, Conus purpurascens, which is essential for quick prey’s excitotoxic immobilization. Binding of one κ-PVIIA to Shaker K-channels occludes the K⁺-conduction pore without additional conformational effects. Because this 27-residue toxin is +4-charged at neutral pH, we asked if electrostatic interactions play a role in binding. With Voltage-Clamp electrophysiology, we tested how ionic strength (IS) affects κ-PVIIA blockade to Shaker. When IS varied from ~0.06 to ~0.16 M, the dissociation constant for open and closed channels increased by ~5- and ~16-fold, respectively. While the association rates decreased equally, by ~4-fold, in open and closed channels, the dissociation rates increased 4–5-fold in closed channels but was IS-insensitive in open channels. To explain this differential IS-dependency, we propose that the bound κ-PVIIA wobbles, so that in open channels the intracellular environment, via ion-conduction pore, buffers the imposed IS-changes in the toxin-channel interface. A Brønsted-Bjerrum analysis on the rates predicts that if, instead of fish, the snail preyed on organisms with seawater-like lymph ionic composition, a severely harmless toxin, with >100-fold diminished affinity, would result. Thus, considerations of the native ionic environment are essential for conotoxins evaluation as pharmacological leads.     

含氨基酸水溶肥料对2株芽孢杆菌的激活作用

含氨基酸水溶肥是一种新型绿色肥料,具有肥效快、无残留、改善作物品质和提高作物抗逆性等优点。将其作为有机载体制备菌肥,对芽孢杆菌生长和繁殖是否具有影响,尚未见报道。本研究分析不同浓度的“绿农林”含氨基酸水溶肥溶液对芽孢杆菌菌株X05和QB61生长繁殖、拮抗代谢物产生以及对番茄、香蕉生长和香蕉枯萎病防效的影响。结果表明：在1~50 g/L供试含氨基酸水溶肥溶液中培养24 h,芽孢杆菌X05和QB61细胞数量增长为初始菌量的86~2900倍,而在清水中培养24 h,细胞数量未发生明显变化;X05和QB61在50 g/L的含氨基酸水溶肥溶液中培养48 h,上清液对香蕉枯萎病菌的生长具有显著的抑制作用,而在其他浓度的含氨基酸水溶肥溶液和清水中培养48 h,上清液均无抑制作用;与单独施用芽孢杆菌X05或QB61处理相比,施用添加芽孢杆菌X05或QB61的含氨基酸水溶肥处理的番茄和香蕉幼苗生长显著增强,同时香蕉枯萎病发病指数分别降低33.4%和32.2%。以上结果表明,供试氨基酸水溶肥可促进芽孢杆菌X05和QB61的生长和繁殖,并使其产生拮抗代谢物,两者混合施用对番茄和香蕉具有更好的促生效果,并可提高芽孢杆菌对香蕉枯萎病的防效。因此,供试的含氨基酸水溶肥与上述的芽孢杆菌组合具有良好的应用前景。