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.     

小豆SSR-PCR反应条件的优化

笔者对小豆SSR-PCR扩增体系的反应条件进行了优化,分析了Mg2+浓度、dNTP浓度、DNA模板浓度、引物浓度、Taq聚合酶浓度对PCR扩增结果的影响。结果表明:在10 μL的PCR反应体系中,Mg2+的最适浓度为2 mmol/L,dNTP最适浓度为0．25 mmool/L,反应体系中Taq聚合酶宜加入1 U,引物的最适浓度为 0．15 mmol/L,DNA模板加入量为20 ng。     

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。     

小豆生长发育规律的研究——Ⅲ.小豆籽粒灌浆进程及播后籽粒干物质转移速率的研究

研究表明:小豆开花后籽粒干物质积累以及播后籽粒干物质转移后的残留量变化呈正态曲线。播后第8天前后为幼苗自身供养与异养的临界期,生育后期的中期为籽粒灌浆的快速时期。     

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...     

净化液处理对豇豆采后多环芳烃(PAHs)的净化效果研究

为降低蔬菜采后体内多环芳烃(PAHs)对人体的危害风险,以豇豆为材料,利用不同浓度洗洁精、食盐、米酒、米醋、植物油及清水分别对豇豆豆荚进行浸洗,通过高效液相色谱-质谱联用法检测豇豆采后体内PAHs的含量,并筛选出豇豆体内PAHs的最佳净化方法。结果表明,米酒和米醋处理对豇豆体内PAHs的去除效果基本一致,其中米酒处理组的∑PAHs（美国环保局公布的优先监测的16种多环芳烃的含量总和）降低68.92%,米醋处理组的∑PAHs降低73.88%,且对萘、二苯并(a,h)蒽和茚并(1,2,3-c,d)芘等均有明显的去除效果;清水浸洗可有效降低豇豆体内的茚并(1,2,3-c,d)芘含量,但会使菲的含量增加;食盐处理使∑PAHs增加了77.15%,主要表现在增加了2、3环PAHs在豇豆体内的积累;植物油处理可降低个别PAHs单体含量,但会引入其他PAHs单体,同时增加∑PAHs含量。毒性当量计算结果表明,米酒能有效降低豇豆体内的PAHs毒性,同时食盐处理也使豇豆体内的PAHs毒性当量降低。米酒和米醋能有效降低豇豆体内∑PAHs和二苯并(a,h)蒽的含量及其毒性当量。     

绿豆抗旱指标鉴选与评价

采用人工盆栽控水试验,对21份绿豆种质资源进行抗旱期综合评价,鉴选绿豆品种抗旱性指标体系。结果表明,与绿豆抗旱性相关的10个指标经主成分分析被分为3个主成分,其中茎高、茎粗、结荚数、叶面积、叶绿素含量、丙二醛含量、脯氨酸含量与绿豆抗旱性密切相关。采用聚类分析,并结合绿豆隶属函数法综合分析,将21份绿豆品种分成：强抗旱品种为‘良丰1号’、‘HX04037’和‘榆绿1号’,中抗旱性品种为‘嫩绿1号’、‘兴绿1号’、‘天山大明绿’、‘西绿1号’、‘绿宝绿豆’、‘赤绿3号’、‘白绿1号’、‘中绿1号’、‘晋绿1号’、‘八宝绿豆’、‘中绿6号’、‘鑫绿1号’和‘HX04050’,弱抗旱性品种为‘冀北12-1号’、‘绿珍珠2号’、‘ZKY-2’、‘白绿522’和‘邯绿8号’。     

Inheritance of Eye Pattern and Seed Coat Colour in Cowpea (Vigna unguiculata [L.] Walp.)

The F₂ progenies of crosses between several cowpea (V. unguiculata) lines were investigated for variation of eye pattern and seed coat colour. It was found that three (W, H, O) and five (R, P, B, M, N) major genes control eye pattern and seed coat colour, respectively. The recessive gene (GO) for restricted eye pattern enables the underlying basic white or cream seed coat colour to be observed. A similar effect is obtained with the recessive gene (rr) for colour expression. The expression of mottling (V), possibly a seed coat pattern, may for be observed when it is combined with the genes for certain eye patterns. The significance of these findings in breeding for consumer preference for specific seed coat colour is discussed.     

Genetical relationships between reactions to bacterial leaf spot,yellow mosaic and Cercospora leaf spot diseases in mungbean (Vigna radiata)

Summary Studies on the inheritance pattern of bacterial leaf spot (BLS), yellow mosaic (YM) and Cercospora leaf spot (CLS) reactions in crosses of BLS and YM resistant/tolerant but CLS susceptible × CLS resistant but BLS and YM susceptible parents indicated that resistances to BLS and CLS were governed by single dominant genes, whereas YM tolerance was a monogenic recessive character. The studies also indicated that these three genes were inherited independently. The simple inheritance pattern and independent assortment of the genes governing resistance/tolerance to these diseases suggest that the usual breeding methods will be adequate to develop multi-disease resistant mungbean cultivars.Paper XII in the series Studies on resistance in crops to bacterial diseases in India.     

Intercropping field crops between rows of Leucaena leucocephala under rainfed conditions in northern India

A field study was conducted for six years (1981–1986) on sandy loam soil on intercropping hedgerows of Leucaena leucocephala (Lam) de Wit. with three field crops viz. maize (Zea mays L), black gram (Vigna mungo L) and cluster bean (Cyamopsis tetragonoloba L Taub.). In treatments 1 and 2 Leucaena hedges were planted as pure crops at close (25 cm × 75 cm) and wide (25 cm × 375 cm) spacings. In treatments 3, 4 and 5 the three field crops were intercropped between the hedgerows of Leucaena at the wide spacing, and in treatments 6, 7 and 8 the field crops were raised as pure crops. Leucaena was topped to 75 cm each time it attained a height of 175 cm. The pure crop of Leucaena at close spacing produced an average, over the six years, of 34 t ha⁻¹a⁻¹ of green fodder and 9.4 t ha⁻¹a⁻¹ of air dry fuelwood. The Leucaena at wide spacing produced 18.9 t ha⁻¹a⁻¹ of green fodder and 6.3 t ha⁻¹a⁻¹ of fuelwood. Intercropping with field crops decreased the yield of green fodder and fuelwood. The yield of all the field crops was less when raised as intercrops than as pure crops. Mean maximum net returns were obtained from intercrops of Leucaena and cluster bean (Rs 3540 ha⁻¹a⁻¹) which were significantly higher than the returns from pure crop of Leucaena at wide spacing but similar to the returns from pure crops of cluster bean. Leucaena with maize (Rs 3273 ha⁻¹a⁻¹) and black gram (Rs 3125 ha⁻¹a⁻¹) gave significantly higher net returns over pure crops of Leucaena at wide spacing, maize and black gram. ICRISAT = International Crops Research Institute for the Semi-Arid Tropics- Hyderabad, India. CIAT = Centro International de Agricultura Tropical - Cali - Columbia