豇豆与锈菌互作中的多酚氧化酶和过氧化物酶活性及其与抗性的关系

测定了具有不同抗性水平的5个豇豆Vigna sesquipdalis Wight品种在受锈菌Uromyces vignae Barcl侵染前和侵染后的若干阶段中的多酚氧化酶(PPO)和过氧化物酶(POD)活性,并分析其与抗性的关系.结果表明,在接种后24h内,免疫和抗病品种的PPO比活性及其变化率均高于感病品种,且前者PPO比活性变化率高峰出现早,后者出现迟.在接种后,各品种的POD比活性及其变化率均上升,但中抗和感病品种的高峰出现早,免疫和高抗品种出现晚.此外,中抗和感病品种的POD比活性及其变化率在接种12h左右出现高峰后立即下降,而高抗品种的则持续上升至24h左右出现高峰,免疫品种的POD比活性也在24h左右出现高峰,但其POD比活性变化率则持续到48h左右达到高峰,且免疫和抗病品种的峰值明显大于感病品种.     

褪黑素诱导小豆抗锈病机理的初步研究

为明确外源褪黑素诱导小豆抗锈性的作用及机理,以感病小豆品种‘宝清红’为材料,采用叶面喷施不同浓度褪黑素激发处理小豆真叶,而后对真叶挑战接种锈菌夏孢子,结果表明,低浓度(11.61 mg/L)褪黑素可显著提升小豆对锈病的抗性。夏孢子萌发试验表明,褪黑素对夏孢子萌发及芽管生长无显著抑制作用,表明褪黑素无抑菌活性。进一步的基因表达分析发现,与对照相比,褪黑素激发诱导了水杨酸(SA)通路关键基因NPR1于接种后24 h显著上调表达,且病程相关蛋白PR1、几丁质酶(CHI)、β-1,3-葡聚糖酶(GLU)及PR5均于接种后24～120 h被显著诱导表达,说明褪黑素可能通过诱导NPR1表达,进而激活下游PR蛋白的高水平应答,使感锈病小豆品种获得对锈病的抗性。     

基于新遗传连锁图谱的豇豆抗豆象QTL定位

【目的】豆象是危害豇豆最主要的仓储害虫。发掘豇豆抗豆象基因为抗性品种的选育,以及减少豆象对豇豆生产的危害奠定基础。【方法】以中豇1号(感)和Pant-lobia-1(抗)为亲本构建的包含282个株系的RIL群体为研究材料,利用人工接种法分别对282个株系接种绿豆象和四纹豆象,进行抗豆象表型鉴定,并利用两亲本对3 992个来源于绿豆、小豆和豇豆的SSR标记进行多态性筛选,然后利用筛选到的多态性标记对282个株系进行基因型分析,最后结合RIL群体各株系抗豆象表型鉴定数据和基因型分型数据,采用完备区间作图法(ICIM-ADD)进行抗豆象QTL定位分析,在此基础上构建遗传连锁图谱,并定位豇豆抗豆象基因。【结果】中豇1号和F1籽粒的被害率均为100%,Pant-lobia-1籽粒的被害率分别为22.5%和42.5%。推测Pant-lobia-1对绿豆象和四纹豆象的抗性均为隐性遗传;筛选到182个多态性标记,利用这些多态性标记构建了一个包含11个连锁群的豇豆遗传连锁图谱,图谱总长1 065.23 cM,相邻标记间平均遗传距离为5.85 cM;经2种豆象处理,分别在连锁群1和连锁群5上检测到2个稳定...     

Indonesian mungbean landraces I. Pure-line selection for yield when intercropped with maize

Summary When mungbean landraces from East Java were intercropped with maize, genetic variation for grain yield was observed. Three cycles of selection resulted in a yield increase of 24% as compared to the original landraces. The yield of the maize component in the mixture was not affected by the increase of the mungbean yield.     

豇豆(Vigna unguiculata)VQ蛋白家族基因的序列与进化分析

VQ蛋白是一类植物特有的转录调控辅助因子,主要与WRKY蛋白互作,参与诸多生物学功能。尽管一些植物VQ家族基因已经被鉴定,但在豇豆中有关VQ家族基因的研究未见报道。本研究利用生物信息学手段从豇豆中鉴定出37个VuVQ基因,并详细分析这些基因的序列、微共线性、表达谱与进化关系。染色体与共线性分析表明,豇豆VuVQ基因定位在11条染色体上,基因扩增主要由片段重复产生,其中4对重复基因所在区段共线性程度高。序列分析结果显示:豇豆VuVQ基因结构有3种类型,绝大多数无内含子;豇豆VQ蛋白均包含VQ结构域,同时这些VQ保守基序数目和顺序变异较高。进化研究揭示豇豆VQ蛋白存在6大类群,这些类群均起源于陆生植物。选择压力检测表示,豇豆的8对VuVQ基因均受严格的负选择。表达分析表明了豇豆VQ基因具有多样化的表达模式,这意味着VQ蛋白参与多种生物学过程。本研究结果为豇豆VQ基因的功能解析提供线索。     

低温处理对豇豆幼苗生长和POD、COD、ATPase同工酶的影响

在０～１℃低温处理豇豆幼苗时幼苗生长明显受抑，检查根系和胚轴中的ＰＯＤ、ＣＯＤ、ＡＴＰａｓｅ同工酶，发现谱带减少。低温对豇豆幼苗生长的伤害与幼苗组织内三种酶同工酶的变化呈明显的相关性。上述三种酶同工酶可以作为一种生化指标用于检测植物幼苗的受寒害状况。     

盐胁迫条件下骆驼刺与绿豆光合日变化特征及午休现象的成因

为了研究盐生豆科植物骆驼刺与盐敏感植物绿豆在盐胁迫下光合日变化与光合“午休”现象的成因,在网室培养,并用0 mmol•L^-1(对照)、50 mmol•L^-1、100mmol•L^-1、200 mmol•L^-1 NaCl处理2周,测定光合作用日变化、叶绿素含量和Rubisco大亚基基因的表达等参数。结果表明：未经盐处理时,骆驼刺和绿豆光合日变化均呈单峰型;经盐处理后,两者光合日变化响应有明显差异。骆驼刺50～200 mmol•L^-1NaCl处理后,其净光合速率（Pn）均比未处理(对照)上升速率快,而其他处理峰值与对照之间没有显著差异;绿豆对照光合速率的上升则比盐处理的快,盐处理光合速率峰值低于对照。骆驼刺50 mmol•L^-1、100 mmol•L^-1和绿豆50 mmol•L^-1处理Pn没有出现“午休”现象,而骆驼刺200 mmol•L^-1处理与绿豆100 mmol•L^-1处理出现“午休”现象。骆驼刺在重度盐胁迫下,由于气孔导度（Gs）下降而引起轻微的“午休”现象,而盐处理绿豆中Rubisco被抑制,对Pn 午休的贡献比其Gs的贡献更为显著。在绿豆中大亚基基因（rbcL）的表达量随着盐胁迫的提高而下降。骆驼刺中rbcL的表达在50 mmol•L^-1和100 mmol•L^-1处理下有所增加,而在200 mmol•L^-1处理显著降低。绿豆和骆驼刺的总叶绿素含量及其Chl a/b比值的动态变化表明,绿豆PSI复合体下降速率较PSII快;与此相反,骆驼刺盐处理后PSI复合体浓度的增加却比PSII复合体快。     

Biocontrol agents in combination with Moringa oleifera extract for integrated control of Sclerotium-caused cowpea damping-off and stem rot

Damping-off and stem rot disease-causing Sclerotium rolfsii has been reported as a destructive soil-borne pathogen of numerous crops, especially in the tropics and subtropics. Trials were conducted to test the efficacy of biocontrol agents alone or combined with Moringa oleifera leaf extracts for the control of the disease. In the laboratory, PDA was amended with Moringa leaf extract, and mycelial growth of S. rolfsii was measured. In the greenhouse and field, Trichoderma Kd 63, Trichoderma IITA 508 and Bacillus subtilis were evaluated as seed treatments, soil drench or sprinkle, separately or combined with Moringa leaf extracts. Percentage disease incidence, severity and control were recorded. In the laboratory, the higher the extract concentration the less the mycelial growth and no mycelial growth occurred on extract at 15 or 20 g leaves 10 ml⁻¹ water. In the greenhouse, the highest disease control was observed at a Moringa extract concentration of 15 kg leaves 10 l⁻¹ water (w/v). Seed treatments using Trichoderma Kd 63, and soil sprinkle using Trichoderma IITA 508 had a significantly (P = 0.05) higher effect on a disease incidence than Bacillus. Disease severity followed the same pattern. Moringa seed treatment combined with Trichoderma soil sprinkle resulted in significantly more than 94% and 70% disease control in the greenhouse and field, respectively, with significant yield increase in the field. This is the first report of Moringa leaf extract combined with Trichoderma as an integrated control for Sclerotium damping-off and stem rot of cowpea in the field.     

New race of <Emphasis Type="Italic">Phytophthora vignae</Emphasis> f. sp. <Emphasis Type="Italic">adzukicola</Emphasis>, the causal agent of Phytophthora stem rot of the adzuki bean

 A new race of Phytophthora vignae f. sp. adzukicola, designated race 4, is reported from central and western Hokkaido, Japan. The isolates obtained from diseased plants of a new cultivar, cv. Syumari, which is resistant to races 1, 2, and 3, were determined to be a new race by the pathogenic reaction on a set of differential adzuki bean cultivars (cv. Erimo-shozu, cv. Kotobuki-shozu, cv. Noto-shozu, cv. Urasa-shimane, and cv. Syumari). Received: March 7, 2002 / Accepted: August 13, 2002     

Cowpea (Vigna unguiculata): Genetics,genomics and breeding

Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.