Genetic diversity among Chinese landraces and cultivars of broomcorn millet (Panicum miliaceum) revealed by the polymerase chain reaction

Broomcorn millet is widely grown in Asia and Europe. This cereal is a very efficient user of soil water and is particularly adapted to sandy, dry soils and dry weather conditions. As one of the oldest crops in ancient China, it has played an important role in the formation and development of Chinese civilisation and culture. It is still one of the major grain crops in northern China where harsh climate conditions prevail. The genetic diversity and relationships among 32 accessions of broomcorn millet (Panicum miliaceum) from the major areas for broomcorn millet growing in China, in addition to six Indian landraces, were evaluated by PCR analysis with six introns splice junction or long random primers. A total of 56 DNA fragments across all materials were scored; among them, 42 (75%) were polymorphic as indicated by their absence in at least 1 of the 38 accessions tested, indicating a high variation at the DNA level among those accessions. Pair‐wise genetic dissimilarity (Dice’s coefficient) ranged from 0.0286 to 0.4737. The clustering largely corroborated with the geographical location of the origins of those accessions. The data indicated that the glutinous/non‐glutinous trait is also associated with the clustering. Majorities of the landraces from Yulin of Shaanxi were clustered into five groups, and majorities of the cultivars or breeding lines from Inner Mongolia were clustered into three groups. The results of this study suggest that the landraces from Yulin of Shaanxi were extensively utilised in the breeding programme of Shanxi, whereas this feature was not observed in the breeding programme of Inner Mongolia.     

通过不对称体细胞杂交向小麦转移青苗碱谷DNA

普通小麦"济南177"(Triticum aestivum L.cv.Jinan177)经继代培养和选择,形成了性质不同的愈伤组织,一种生长迅速,易于形成悬浮系,游离的原生质具有旺盛的分裂能力,但不能分化,称为Cha9;另一种具有一定能力,但游离原生质体分裂能力低,称为176.二者之一来源的原生质体与紫外线照射的青苗碱谷原生质体融合均不能获得再生植株.而将源于Cha9和176的两种原生质体混合,与经紫外线照射的青苗碱谷原生质体在PEG诱导下融合,融合产物再生了大量植株.再生的愈伤组织及植株经表现型、细胞学、有工酶、RAPD分析,证明了其杂种性质,用不麦叶绿体特异的简单得复序列(SSR)引物分析了再生杂种的叶绿体遗传组成情况.在不同的杂种克隆中,同时带有Cha9和176的遗传物质并含有供体核及胞质基因组的克隆4具有较高的分化能力,再生了大量生长旺盛的完整植株.     

安徽虫瘟霉的黍米培养及其对桃蚜的侵染力

安徽虫瘟霉Zoophthora anhuiensis (Li) Humber是较难人工培养的蚜虫专化性病原真菌。将灭菌并适度熟化的黍米Panicum miliaceum L.作为固体基质与挑碎的安徽虫瘟霉平板菌落混合,在20℃和12L∶12D的温光条件下静止固体培养,获得了产孢潜能大、杀蚜活性强的米粒培养物。培养7天的黍米的产孢量达13.0×10⁴个孢子/粒,产孢持续时间长达6天。用此黍米培养物弹射的孢子对桃蚜Myzus persicae (Sulzer) 若蚜进行7.9～134.9个孢子/mm²共9个剂量的孢子浴接种,所获数据很好拟合时间 剂量 死亡率模型。接种后第5～7天各天的LC₅₀依次为59.8, 39.5和33.5个孢子/mm²,LC₉₀依次为354,234和198个孢子/mm²。在57.7～134.9个孢子/mm²的接种剂量范围内,致死中时LT₅₀从5.1天下降到4.3天。由此表明,安徽虫温霉的黍米培养不仅简单易行,而且菌种的产孢和侵染生物学特性在培养物中被充分体现,每颗米粒如同自然罹病而死的蚜尸,值得进一步研究开发和利用。     

陕北榆林王阳畔遗址的植硅体分析

榆林地处农牧交错带,是研究环境演变和人地关系的理想地区。本文基于植硅体分析,探讨了该地区王阳畔遗址仰韶晚期至龙山早期过渡阶段的农业生产情况及农业对环境的适应等。遗址剖面及灰坑样品的植硅体分析表明:仰韶晚期,粟和黍是先民的主要粮食作物,而黍较粟始终保持着种植优势;龙山早期,粟作农业逐渐衰落。植硅体组合图谱显示,先民在此遗址活动期间,气候是略偏凉偏干的,整体上较为稳定,呈现出干凉化的趋势。综合来看,农业活动的强弱在一定程度上响应了环境的变化。需要指出的是,该遗址榆科植硅体的大量发现,不仅补充了史前植物利用史,同时也对丰富植硅体数据库具有重要意义。     

抗、感黑穗病谷子品种几种酶活性的比较研究

本文对7个不同抗、感黑穗病的谷子品种在不同时期进行了超氧化物歧化酶、过氧化物酶、多酚氧化酶活性的比较研究。结果表明,谷子感染黑穗病后,体内超氧化物歧化酶、过氧化物酶、多酚氧化酶活性均显著增强。抗病品种的酶活性明显地高于感病品种。这些酶活性的变化能够削弱或消除病菌对谷子的毒害作用,在谷子抗黑穗病过程中发挥重要作用。     

糜子育成品种芽期抗旱性鉴定与评价研究

采用PEG6000胁迫处理对国内不同地区育成的56个糜子品种的芽期抗旱性进行了鉴定,并用直接评价和综合评价法对其抗旱性进行了评价。结果表明:经20%(W/V)PEG6000处理的56个品种与对照相比性状之间差异显著,品种抗旱性存在较大差异。用直接评价法和综合评价法相结合鉴定出强抗旱性品种3份,分别是晋黍2号、陇糜5号和陇糜8号。相对发芽率、相对芽干重、相对根干重、贮藏物质相对转运率4项指标可作为糜子芽期抗旱性鉴定评价指标,相对发芽率法和加权隶属函数值法是比较理想的糜子芽期抗旱性评价方法。     

谷子茎尖体外遗传转化体系的建立与优化

以谷子(Seteria italica)豫谷一号为实验材料, 建立了一套简便、稳定的体外茎尖遗传转化体系。通过根癌农杆菌(Agrobacterium tumefaciens)介导的茎尖转化法, 对转化受体采取不同的处理方式, 待拟转化株长到三叶期后进行PCR鉴定。探明了草丁膦(Basta)喷施处理用于谷子转基因幼苗筛选的最适浓度, 以及2种不同检测方式(直接PCR和喷施Basta+PCR)鉴定转基因植株的效果。在上述基础上, 对影响谷子遗传转化体系的多种因素进行优化。结果表明, 菌液浓度(OD₆₀₀)=1.4、侵染液中乙酰丁香酮浓度为800 μmol∙L ^-1、侵染压强为0.05 MPa、侵染40分钟有利于谷子茎尖的遗传转化。同时, 采用上述优化系统获得谷子转SiCBL4基因植株, 通过喷施草丁膦和实时荧光定量PCR对T₂代转基因植株进行遗传稳定性分析, 可节约检测时间。综上, 该研究初步建立了稳定的谷子体外茎尖遗传转化体系, 并开发了一种便捷的检测后代转基因植株的组合方法。     

Inheritance of downy mildew resistance, β-1,3-glucanases and peroxidases in pearl millet [Pennisetum glaucum (L.) R. Br.] crosses

The inheritance of resistance to downy mildew disease and the defense-related enzymes β-1,3-glucanase and peroxidase was studied in crosses of pearl millet using a generation-mean analysis. The study material comprised six generations (susceptible and resistant parents, F₁, F₂, BC₁ and BC₂) in three crosses. Seedlings from these generations were inoculated with the downy mildew pathogen Sclerospora graminicola and disease incidence was recorded. Analysis of constitutive levels of β-1,3-glucanase and peroxidase in the seedlings of different generations indicated that the resistant populations showed higher enzyme activities, while lower activities of the enzymes were recorded in the susceptible populations. In the generation-mean analysis, the significance of scaling tests revealed the existence of non-allelic interactions in the inheritance of resistance to downy mildew as well as with the enzymes. Among the gene effects, both additive and dominant effects were significant. All the non-allelic interaction effects were significant in the crosses. Studies on the isozyme patterns of the enzymes substantiated the results of the disease-incidence experiments in most of the generations. The results indicated that the inheritance of downy mildew disease resistance and the expression of β-1,3-glucanase and peroxidase in pearl millet is not only under the control of additive and dominant genes but are also governed by complex non-allelic interactions. Received: 30 April 2000 / Accepted: 17 October 2000     

不同除草剂的田间杂草防效及对糜子生长发育的影响

筛选糜子适宜除草剂来防范农田药害,是糜子高效安全生产和改善生态环境亟待解决的关键问题。本研究以粳性糜子品种‘榆糜2号'为材料,探究22种除草剂对糜子田间杂草的防除效果及对糜子生长发育的影响。结果表明: 1)喷施土壤封闭型除草剂谷友、丁草胺、莠去津、苄嘧·丙草胺和茎叶型除草剂苯唑·二甲钠、阔世玛、藤净、陶氏·优先、阔菲后,基本无药害作用,糜子幼苗生长正常,其余除草剂均对糜子有不同程度的药害影响;2)参试的22种除草剂在糜子田中对杂草均表现出一定的防除效果,总体而言,土壤封闭型除草剂的杂草防效相对优于茎叶型除草剂,但所有参试除草剂对糜子株高、功能叶片叶绿素含量、单株穗重均造成不同程度的影响;3)与人工除草相比,参试除草剂均导致糜子产量有不同程度的下降;但与不除草对照相比,部分除草剂有明显的增产增效作用。土壤封闭型除草剂中,谷友、丁草胺、莠去津、苄嘧·丙草胺的杂草防效较好,较不除草对照增产60%以上;茎叶型除草剂中,阔世玛、苯唑·二甲钠的杂草防效较好,较不除草对照增产50%以上。因此,在糜子出苗前可用38%莠去津或44%单嘧磺隆进行土壤封闭处理,或在出苗后喷施茎叶型除草剂3.6%二磺·甲碘隆或55%苯唑·二甲钠,农田杂草防效较好,且对糜子生长发育的负面影响较小。     

谷子秸秆不同部位水浸液对3种杂草的化感作用

通过测定种子萌芽期生物学指标和盆栽苗期生理指标,研究谷子不同部位(叶片、茎秆)不同浓度(原液、10倍稀释液、50倍稀释液、100倍稀释液)浸提液对反枝苋、藜、狗尾草3种谷田恶性杂草的化感作用。结果表明: 谷子叶片、茎秆水浸提液对3种杂草均存在显著化感作用,且不同浓度浸提液化感作用存在差异,总体表现为原液有抑制作用,稀释液(10、50、100倍)有促进作用。叶片、茎秆浸提液原液处理下,反枝苋、藜、狗尾草的发芽率分别下降了63.9%、37.3%和41.7%,根长仅为对照的27.8%、37.8%和18.4%,芽长仅为对照的34.5%、27.7%和17.6%,净光合速率为对照的66.6%、89.9%和88.2%,蒸腾速率为对照的69.0%、87.5%和56.1%,原液对3种杂草的综合化感效应指数为-0.699、-0.716和-0.795,表现出较强的化感抑制作用。稀释液处理下化感促进作用随稀释倍数增加呈先上升后下降趋势,其中50倍稀释液促进作用最强,3种杂草的发芽率、根长和芽长均与对照达到差异显著水平,综合化感效应指数分别为0.261、0.217和0.165。谷田伴生杂草大量生长与谷子秸秆中化感物质淋溶有关。