伞房决明的引种和栽培应用

伞房决明Ｃａｓｓｉａｃｏｒｙｍｂｏｓａ原产南美的阿根廷,在北美洲已广为驯化栽培。我国自二十世纪九十年代开始引种。我们也于１９９４年春开始了对伞房决明的引种,经多年的试验观察,引种在本地区获得初步的成功;现介绍如下：伞房决明为灌木,偶数羽状复叶,具柄,黄绿色小叶２—３对,小叶矩圆状披针形,长２５－５ｃｍ,顶端稍尖,最下方的一对小叶之间有一腺体,花黄色,花瓣阔,长１３ｃｍ,列成具长梗的腋生小形伞房花序,通常较叶为长,能育雄蕊７,荚果圆柱形,长５—８ｃｍ,种子棕色,有光泽。伞房决明在本地区的芽…     

华南地区5 种野生灌木的抗旱性评价

选取华南地区常见的野生灌木春花(Rhaphiolepis indica)、米碎花(Eurya chinensis)、檵木(Loropetalum chinense)、黑面神(Breynia fruticosa)和野牡丹(Melastoma candidum)为试材, 以边坡复绿常用外来种伞房决明(Cassia corymbosa)做对照, 采用PEG 模拟干旱胁迫方法进行苗期处理, 探讨其在不同的PEG 浓度(5%、10%、20%)和不同胁迫时间(24 h、48 h)条件下生理指标的变化规律, 并对其抗旱性进行综合评价, 旨为华南地区裸露边坡生态修复筛选优良耐旱灌木。结果表明: 随着胁迫程度加剧, 各物种的叶片相对含水量均有不同幅度的下降, 在重度胁迫下仍保持较高含水量的物种有春花、伞房决明、檵木和黑面神; 相对电导率和丙二醛含量均随胁迫时间延长而增加; 脯氨酸和可溶性糖含量则随胁迫时间延长呈先升后降和持续增加两种变化趋势, 因不同物种而异。以各生理指标的平均变化速率 为原始数据进行主成分分析得出, 6 种灌木抗旱性强弱依次排序为: 檵木>春花>米碎花>伞房决明>黑面神>野牡丹。     

梨花迁粉蝶成虫的产卵行为

【背景】梨花迁粉蝶是园林植物伞房决明、黄花决明、铁刀木上的主要害虫。【方法】在福建省三明市明溪县蝴蝶生态园内观察不同时段梨花迁粉蝶成虫的飞行活动与产卵行为。【结果】梨花迁粉蝶成虫的飞行活动与产卵行为密切相关（R=0．9406）,飞行与产卵频率都是在上午8：00～11：00较高。梨花迁粉蝶卵多产于第2和第3片复叶,第6片复叶上未发现卵;同时,梨花迁粉蝶卵多产于复叶末端的小叶上,其临近叶片上的卵量逐渐减少;叶片正面和背面的卵量差异不显著;植株新芽、茎秆、花等部位上的产卵量极少;梨花迁粉蝶在盆栽决明和水培决明上的产卵量无显著差异。【结论与意义】梨花迁粉蝶飞行与产卵有特定的规律,这对于其田间调查和防治具有重要意义。     

观赏药用植物──望江南

望江南(Cassia occidentalis)又名羊角豆、喉白草、假决明，为苏木科决明属植物，多年生常绿灌木或半灌木。枝条柔软，微下垂。叶淡绿色，互生，偶数羽状复叶，叶柄上面近基部有一个腺体；小叶6—10，对生，卵形或卵状披针形，长2cm，宽1cm左右，边缘有细毛；每年10月至翌年4月开花，伞房状总状花序顶生或腋生，花瓣5，黄色；荚果圆柱形，略扁，形似羊角，淡黄棕色；种子30—53枚，卵形，稍扁，黑褐色，成熟期元月下旬至三月中旬。望江南主要分布于我国的福建、台湾、两广、云南等地区，国外分布于印度及其它热带地区；性喜高温，但对低…     

中国南部锈菌新资料

描述了崖豆藤伞锈菌大头变种(新变种)Ravenelia millettiae var.major var.nov.。建立了新组合红豆细柄锈菌Atelocauda ormosiae com.nov.(≡Uromyces ormosiae)。报道了四个中国新记录:海南崖豆藤Millettia pachyloba上的刚刺品字锈菌Hapalophragmium setulosum、假通草Euaraliopsis ciliata上的刺通草花孢锈菌Nyssopsora trevesiae、黄槐决明Cassia surattensis上的鲍姆伞锈菌Ravenelia baumiana和黄豆树Albizia procera上的克莱门斯伞锈菌Ravenelia clemensae。     

蒙古高原绣线菊属植物演化系统的研究

利用最小平行进化法对蒙古高原绣线菊属植物进行了分支分类研究,将本属植物分为4个组、6个系。其组的进化顺序为：Sect.Spiraea→Sect.Calospira→Sect.Glomerati→Sect.Chamaedryon。本属的进化趋势为冬芽芽鳞由数枚减少到2枚,花序由总状圆锥花序→复伞房花序→伞房花序→伞形花序。研究认为绣线菊属是泛北极起源。     

新番茄粉孢——我国番茄白粉病菌一新记录

Kiss et al.(2001)依据形态学特征、分生孢子表面的超微结构和分子系统学数据把寄生在番茄Lycopersicon esculentum Mill.上的粉孢属Oidium的种鉴定为两个种,即番茄粉孢Oidium lycopersici Cooke & Massee和新番茄粉孢O.neotycopersici L.Kiss.     

HPLC测定决明不同组织中大黄酚和橙黄决明素含量

为了测定决明不同组织中大黄酚和橙黄决明素的含量。分别收集了决明种子、根、茎、花、叶、果荚、子叶、胚轴、愈伤与不定根等组织,利用回流提取法提取大黄酚与橙黄决明素,高效液相色谱法(HPLC)进行含量测定。采用依利特反相色谱柱,以大黄酚和橙黄决明素为指标,以乙腈-0.1%磷酸水为流动相进行梯度洗脱,流速1 m L/min,检测波长为284 nm,柱温30℃。结果表明:大黄素型蒽醌类化合物在决明中的分布具有明显的组织特异性,其中,决明种子、胚轴、不定根、子叶与愈伤组织中含有大黄酚与橙黄决明素,决明根中仅含有大黄酚,其余组织不含有大黄酚与橙黄决明素,其余总蒽醌含量依次为子叶不定根愈伤组织胚轴根花。决明种子成熟过程中,大黄酚的含量呈现"波浪式上升"的趋势,峰值出现在11月下旬;而橙黄决明素的含量呈现"先上升后下降"的趋势,峰值出现在11月中旬。由于大黄酚与橙黄决明素的含量在决明不同成熟时期分别出现峰值,建议采收11月下旬的决明种子以获得大黄酚,采收11月中上旬的决明种子以获得较多的橙黄决明素。     

性诱剂监测吉林省水稻二化螟成虫动态及发生世代研究

1998～1999年在吉林省用性诱剂水盆监测二化螟雄蛾季节动态和发生世代,结果发现,1998年长春市越冬代成虫始见期在5月电旬,柳河县在5月底左右,长春市成虫终见期。1998和1999年分别为9月下旬和上旬。可见长春市二化螟成虫伞季活动朔可能长达4个月,而1个世代的历期约为2个月。1999年长春市出现两个相距55天的明显蛾峰,表明存在相当高的二代转化率,从而有助于改变该地二化螟常年只发生1代的传统观点。     

决明查尔酮合成酶基因的克隆及序列分析

以决明(Cassia tora)为实验材料,利用RT-PCR和RACE技术,从决明嫩叶中克隆出查尔酮合成酶(Chal-one synthase,CHS)基因,其cDNA全长为1 459 bp,编码一个由390个氨基酸残基组成的多肽.氨基酸序列分析表明,决明CHS基因的氨基酸序列中含有44.61%的中性疏水氨基酸,29.74%的中性亲水氨基酸,12.56%的酸性氨基酸和13.O8%的碱性氨基酸.决明CHS基因的氨基酸序列中具有CHS家族酶系的氨基酸保守残基,包括结合底物CoA的结合残基及催化聚酮合成的催化残基,表明其可能参与聚酮化合物的合成.决明与其它植物CHS的氨基酸序列的进化分析表明,其与同为豆科决明属的翼叶决明(Cassia alata)的同源性较近,并且CHS家族可以分为CHS亚家族与非CHS亚家族.将得到的序列提交GenBank,登录号为EU430077.     

Effects of Sunflower Oil on Tomato Powdery Mildew Caused by Oidium neolycopersici

When tomato leaves were sprayed with 0.1% emulsified canola oil, corn oil, grape seed oil, peanut oil, safflower oil, soya bean oil or sunflower oil, the severity of powdery mildew caused by Oidium neolycopersici was greatly reduced. Among these edible oils tested, sunflower oil was the most effective in the control of powdery mildew. When sprayed with 0.5% sunflower oil, powdery mildew on tomato leaves was reduced to a negligible level. Sunflower oil applied to halves of upper leaf surface did not induce resistance against the pathogen in the non‐treated halves. When applied to halves of lower leaf surface, it also failed to reduce the severity of powdery mildew on the upper leaf surface right above the treated area indicating that control of the powdery mildew by sunflower oil did not result from activation of host defence mechanisms. Scanning electron microscopy showed that control of powdery mildew with sunflower oil resulted mainly from the inhibition of conidial germination and suppression of mycelial growth of the pathogen.     

The powdery mildew disease of rubber (Oidium heveae) is jointly controlled by the winter temperature and host phenology

International Journal of Biometeorology - Rubber powdery mildew disease (Oidium heveae) is a serious threat to natural rubber production (Hevea brasiliensis) in some rubber developing regions of...     

Mango powdery mildew Oidium mangiferae an alternative food for the predatory mites Typhlodromus mangiferus and Typhlodromips swirskii (Phytoseiidae) in absence or presence increasing prey density of Oligonichus mangiferus (Tetranychidae) in Egypt

The predacious mites, Typhlodromus mangiferus Zaher and El-Borolossy and Typhlodromips swirskii (Athias-Henriot), reproduced successfully on mango powdery mildew Oidium mangiferae Berthet in absence or presence of spider mite prey Oligonichus mangiferus (Rahman and Sapra) under laboratory conditions of 25 ± 1°C and 60–65% R.H. Adult female of both predators consumed protonymphs of O. mangiferus at different experimental densities. The consumption rate increased with increasing prey densities up to 25 protonymphs/female/day and decreased significantly at 35 and 50 protonymphs/female/day for the two predatory mites. Addition of powdery mildew conidia to each prey density significantly reduced consumption of spider mites at 35 and 50 protonymphs/female/day. Mean eggs/female/day by T. swirskii and T. mangiferus was 0.30 and 0.72 when reared on powdery mildew conidia compared with 1.64 and 1.57 when fed on powdery mildew and tetranychid prey, respectively. This increase in reproduction would have compensated the reduction in protonymph prey consumption due to the presence of mildew conidia. Mite–mildew interactions are discussed.     

QTLs for tomato powdery mildew resistance (Oidium lycopersici) in Lycopersicon parviflorum G1.1601 co-localize with two qualitative powdery mildew resistance genes

Tomato (Lycopersicon esculentum) is susceptible to the powdery mildew Oidium lycopersici, but several wild relatives such as Lycopersicon parviflorum G1.1601 are completely resistant. An F2 population from a cross of Lycopersicon esculentum cv. Moneymaker x Lycopersicon parviflorum G1.1601 was used to map the O. lycopersici resistance by using amplified fragment length polymorphism markers. The resistance was controlled by three quantitative trait loci (QTLs). Ol-qtl1 is on chromosome 6 in the same region as the Ol-1 locus, which is involved in a hypersensitive resistance response to O. lycopersici. Ol-qtl2 and Ol-qtl3 are located on chromosome 12, separated by 25 cM, in the vicinity of the Lv locus conferring resistance to another powdery mildew species, Leveillula taurica. The three QTLs, jointly explaining 68% of the phenotypic variation, were confirmed by testing F3 progenies. A set of polymerase chain reaction-based cleaved amplified polymorphic sequence and sequence characterized amplified region markers was generated for efficient monitoring of the target QTL genomic regions in marker assisted selection. The possible relationship between genes underlying major and partial resistance for tomato powdery mildew is discussed.     

Naturally occurring broad-spectrum powdery mildew resistance in a Central American tomato accession is caused by loss of mlo function

The resistant cherry tomato (Solanum lycopersicum var. cerasiforme) line LC-95, derived from an accession collected in Ecuador, harbors a natural allele (ol-2) that confers broad-spectrum and recessively inherited resistance to powdery mildew (Oidium neolycopersici). As both the genetic and phytopathological characteristics of ol-2-mediated resistance are reminiscent of powdery mildew immunity conferred by loss-of-function mlo alleles in barley and Arabidopsis, we initiated a candidate-gene approach to clone Ol-2. A tomato Mlo gene (SlMlo1) with high sequence-relatedness to barley Mlo and Arabidopsis AtMLO2 mapped to the chromosomal region harboring the Ol-2 locus. Complementation experiments using transgenic tomato lines as well as virus-induced gene silencing assays suggested that loss of SlMlo1 function is responsible for powdery mildew resistance conferred by ol-2. In progeny of a cross between a resistant line bearing ol-2 and the susceptible tomato cultivar Moneymaker, a 19-bp deletion disrupting the SlMlo1 coding region cosegregated with resistance. This polymorphism results in a frameshift and, thus, a truncated nonfunctional SlMlo1 protein. Our findings reveal the second example of a natural mlo mutant that possibly arose post-domestication, suggesting that natural mlo alleles might be evolutionarily short-lived due to fitness costs related to loss of mlo function.     

Powdery mildew (Ascomycotina: Erysiphales) — an alternative food for the predatory mite Typhlodromus pyri Scheuten (Acari: Phytoseiidae)

The ability of Typhlodromus pyri Scheuten to feed on powdery mildew was investigated. Adult females of T. pyri which had previously been fed on the pollen of Pinus sylvestris L. were offered three powdery mildew species and their feeding behaviour was observed. The females fed readily on the conidia of Erysiphe orontii Cast. from tobacco and Oidium fragariae Harz. from strawberry while no feeding was observed on Erysiphe polygoni DC. from red clover, even after the mites were starved for 2 days. Erysiphe orontii was tested for its effect on the survival, oviposition and development of T. pyri. The results showed that the conidia of E. orontii can supply mites with the water and nutrients necessary for their normal development. Mature females successfully mated and reproduced, although their oviposition rate was low. This revised version was published online in November 2006 with corrections to the Cover Date.     

橡胶树白粉菌分支酸变位酶基因克隆及蛋白表达纯化

由橡胶树白粉菌引起的橡胶树白粉病是橡胶树的重要的叶部病害之一,严重影响橡胶的产量。然而目前对橡胶树白粉菌的致病机理研究匮乏。分支酸变位酶是莽草酸途径的关键酶,能够将分支酸转化为预苯酸,为植物提供氨基酸及大量代谢产物,在植物抗病中起到非常重要的作用。而植物病原物在致病过程当中能够分泌分支酸变位酶影响植物莽草酸途径,从而抑制植物的防卫反应。因此研究橡胶树白粉菌分支酸变位酶在其致病过程中的功能具有一定的意义。试验利用同源比对分析在橡胶树白粉菌基因组中获得一个分支酸变位酶同源蛋白,并用PCR克隆获得橡胶树白粉菌分支酸变位酶基因,命名为OHCmu。后续构建GST-OHCmu融合原核表达载体,筛选最优诱导条件,并利用GST亲和层析柱对蛋白进行纯化。结果表明橡胶树白粉菌OHCmu基因大小843 bp,具有1个内含子,编码263个氨基酸;具有d5csma_结构域,属于Chorismate mutaseⅡ蛋白家族;GST-OHCmu融合蛋白外源诱导表达在供试条件下(IPTG:0.8 mmol/L, 16℃)可以有较好的表达,获得融合蛋白大小约为56 kD。经过GST亲和层析柱纯化、切割GST标签后,顺利获得浓度较高、较纯的橡胶树白粉菌OHCmu蛋白。研究结果为后续OHCmu蛋白的特性及致病机理研究提供参考。     

Tomato defense to Oidium neolycopersici: dominant Ol genes confer isolate-dependent resistance via a different mechanism than recessive ol-2

Tomato powdery mildew caused by Oidium neolycopersici has become a globally important disease of tomato (Lycopersicon esculentum). To study the defense responses of tomato triggered by tomato powdery mildew, we first mapped a set of resistance genes to O. neolycopersici from related Lycopersicon species. An integrated genetic map was generated showing that all the dominant resistance genes (Ol-1, Ol-3, Ol-4, Ol-5, and Ol-6) are located on tomato chromosome 6 and are organized in three genetic loci. Then, near-isogenic lines (NIL) were produced that contain the different dominant Ol genes in a L. esculentum genetic background. These NIL were used in disease tests with local isolates of O. neolycopersici in different geographic locations, demonstrating that the resistance conferred by different Ol genes was isolate-dependent and, hence, may be race-specific. In addition, the resistance mechanism was analyzed histologically. The mechanism of resistance conferred by the dominant Ol genes was associated with hypersensitive response, which varies in details depending on the Ol-gene in the NIL, while the mechanism of resistance governed by the recessive gene ol-2 on tomato chromosome 4 was associated with papillae formation.     

Molecular phylogenetic and morphological analyses of Oidium heveae, a powdery mildew of rubber tree

Powdery mildew of rubber tree caused by Oidium heveae is an important disease of rubber plantations worldwide. Identification and classification of this fungus is still uncertain because there is no authoritative report of its morphology and no record of its teleomorphic stage. In this study, we compared five specimens of the rubber powdery mildew fungus collected in Malaysia, Thailand, and Brazil based on morphological and molecular characteristics. Morphological results showed that the fungus on rubber tree belongs to Oidium subgen. Pseudoidium. Nucleotide sequence analysis of the ribosomal DNA internal transcribed spacer (ITS) region and the large subunit rRNA gene (28S rDNA) were conducted to determine the relationships of the rubber powdery mildew fungus and to link this anamorphic fungus with its allied teleomorph. The results showed that the rDNA sequences of the two specimens from Malaysia were identical to a specimen from Thailand, whereas they differed by three bases from the two Brazilian isolates: one nucleotide position in the ITS2 and two positions in the 28S sequences. The ITS sequences of the two Brazilian isolates were identical to sequences of Erysiphe sp. on Quercus phillyraeoides collected in Japan, although the 28S sequences differed at one base from sequences of this fungus. Phylogenetic trees of both rDNA regions constructed by the distance and parsimony methods showed that the rubber powdery mildew fungus grouped with Erysiphe sp. on Q. phillyraeoides with 100% bootstrap support. Comparisons of the anamorph of two isolates of Erysiphe sp. from Q. phillyraeoides with the rubber mildew did not reveal any obvious differences between the two powdery mildew taxa, which suggests that O. heveae may be an anamorph of Erysiphe sp. on Q. phillyraeoides. Cross-inoculation tests are required to substantiate this conclusion.     

The Arabidopsis genes RPW8.1 and RPW8.2 confer induced resistance to powdery mildew diseases in tobacco

Plant disease resistance (R) gene products recognize pathogen avirulence (Avr) gene products and induce defense responses. It is not known if an R gene can function in different plant families, however. The Arabidopsis thaliana R genes RPW8.1 and RPW8.2 confer resistance to the powdery mildew pathogens Erysiphe orontii, E. cichoracearum, and Oidium lycopersici, which also infect plants from other families. We produced transgenic Nicotiana tabacum, N. benthamiana, and Lycopersicon esculentum plants containing RPW8.1 and RPW8.2. Transgenic N. tabacum plants had increased resistance to E. orontii and O. lycopersici, transgenic N. benthamiana plants had increased resistance to E. cichoracearum, but transgenic L. esculentum plants remained susceptible to these pathogens. The defense responses induced in transgenic N. tabacum and N. benthamiana were similar to those mediated by RPW8.1 and RPW8.2 in Arabidopsis. Apparently, RPW8.1 and RPW8.2 could be used to control powdery mildew diseases of plants from other families.