几种除草剂对胡麻田裸燕麦(莜麦)、皮燕麦的防除效果

本文开展了唑啉草酯等7种除草剂对胡麻田裸燕麦、皮燕麦的防除试验研究,结果表明,在胡麻株高5~7cm,裸燕麦、皮燕麦3~5叶期施药,50g/L唑啉草酯乳油、108g/L高效氟吡甲禾灵乳油、15%精吡氟禾草灵乳油、240g/L烯草酮乳油和10%精喹禾灵乳油有效成分剂量分别为90、145.8、315、432和90g/hm2时,药后45d对裸燕麦的株防效达95.39%以上,鲜重防效达97.21%以上,胡麻增产率在82.79%以上;50g/L唑啉草酯乳油、108g/L高效氟吡甲禾灵乳油、15%精吡氟禾草灵乳油、15%炔草酯可湿性粉剂、10%精喹禾灵乳油和12.5%烯禾啶乳油有效成分剂量分别为90、145.8、270、135、90和412.5g/hm2时,药后45d对皮燕麦的株防效在94.66%以上,鲜重防效达96.13%以上,胡麻增产率在80.25%以上,各药在上述剂量下防治裸燕麦和皮燕麦后均对胡麻表现安全,可大面积示范推广。     

燕麦DNA在小麦抗条锈病育种中的利用

以健壮燕麦Avena sativa L.为供体,以普通小麦品种宁春4号为受体,利用花粉管通道将燕麦总DNA导入小麦中。对供体、受体、导入后代各变异株系进行连续4年的成株期混合菌种的抗病性鉴定和2年的分生理小种鉴定。结果显示:供体对小麦条锈菌免疫,受体对小麦条锈菌各生理小种严重感染,导入后代中有6个株系对小麦条锈菌各生理小种均表现高抗。表明燕麦DNA上可能携有抗小麦条锈菌的新基因,并已通过花粉管通道进入小麦,整合到小麦的染色体组中,稳定地表达。     

Distribution of diclofop-methyl and metabolites in oat (Avena sativa L.) protoplasts

The metabolism of the herbicide diclofop-methyl and the distribution of it and its metabolites have been investigated in a system utilizing isolated oat protoplasts (Avena sativa L. ‘Cascade’). Accumulations of ¹⁴C-diclofop-methyl were found in membrane fractions of the protoplasts. Diclofop-methyl partitioned into the lipid phase of the protoplast plasma membrane. Comparatively small amounts of diclofop were found associated with the protoplasts. Diclofop-methyl was converted to diclofop in the treatment solution by hydrolytic enzymes associated with the external surface of the protoplast. Approximately 78% of the radiolabel recovered from the treatment solution was diclofop. The two major accumulations of radiolabel were found in the water insoluble portion (membrane fraction) of the protoplast as diclofop-methyl and in the treatment solution as diclofop. Repartition du diclofop-methyl et de ses métabolites dans les protoplastes d'avoine (Avena sativa L.) Le métabolisme de l'herbicide diclofop-methyl (DM) et la répartition du DM et de ses métabolites ont étéétudiés dans un système faisant appel à des protoplastes d'avoine isolés (Avena sativa L.) ‘Cascade’. Des accumulations de ¹⁴C-diclofop-methyl ont été trouvées dans la fraction membranaire des protoplastes. Le diclofop-methyl est passé dans la phase pidique de la membrane plasmique du protoplaste. En comparaison, de petites quantités de diclofop ont été trouvées en association avec les protoplastes. Le diclofop-methyl a été converti en diclofop par des hydrolases associées à la surface externe des protoplastes. Approximativement 78% des traces radioactives retrouvées dans la solution de traitement étaient du diclofop. Les deux principales accumulations de radioactivitéétaient trouvées dans la fraction insoluble dans l'eau des protoplastes (fraction membranaire) sous forme de diclofop-méthyl et, dans la solution de traitement, sous forme de diclofop. Verteilung von Diclofop-methyl und Metaboliten in Hafer- (Avena sativa L.)-Protoplasten Der Abbau von ¹⁴C-markiertem Diclofop-methyl und die Verteilung des Wirkstoffs sowie eines Metaboliten wurden in isolierten Protoplasten von Hafer (Avena sativa L. ‘Cascade’) untersucht. Der Wirkstoff war in den Protoplastenmembranen angereichert, wobei eine Anlagerung an die Lipidphase der Plasmamembran festgestellt wurde. Von Diclofop waren vergleichsweise geringe Mengen an die Protoplasten gebunden. Diclofop-methyl wurde in der Versuchslösung durch hydrolytische Enzyme, die an der Protoplastenaussenfläche lagen, zu Diclofop umgewandelt. Radioaktiv markierte Stoffe wurden hauptsächlich als Diclofop-methyl am Protoplasten-membransystem und als Diclofop (mit 78% der eingebrachten ¹⁴C-Aktivität) in der Lösung gefunden.     

Mitotic disruption by a novel pyrimidine herbicide, NS-245852, in oat (Avena sativa L.) roots

The effects of a novel pyrimidine herbicide, NS-245852 [2-chloro-6-fluorophenyl-4-(trifluoromethyl)thieno[2,3-d]pyrimidine-2-yl-ketone], on mitosis in oat ( Avena sativa L. cv. Zenshin) root tips were investigated by using light and immunofluorescence microscopy. The root growth was strongly inhibited at 10⁻⁷ mol L⁻¹ of NS-245852, and swollen root tips were induced at 5 × 10⁻⁸ mol L⁻¹. As observed by the use of light microscopy, the herbicide produced disrupted mitosis and large polynucleate cells in the meristematic root tissue. These symptoms were similar to those of mitotic disrupter herbicides. The immunofluorescence microscopy studies of the root tip cells treated for 30 min revealed that spindle fibers and the preprophase band were reduced, although kinetochore fibers and the phragmoplast were not affected. Kinetochore fibers remained as small fluorescence spots, and the phragmoplast disappeared after a 3 h treatment. No microtubule arrays were observed by a longer treatment (longer than 3 h). Among the microtubule arrays, spindle fibers and the preprophase band were found to be the most sensitive to the herbicide, whereas kinetochore fibers were the most resistant. The phragmoplast was intermediate. Thus, the primary action of NS-245852 is the inhibition of polymerization of tubulin into microtubules.     

Partial purification and properties of S-cysteinyl-hydroxychlorpropham transferase from oat (Avena sativa L.)

S-Cysteinyl and glutathione conjugates of isopropyl-3′-chloro-4′-hydroxycarbanilate (4-hydroxychlorpropham) were synthesized directly in the presence of soluble enzyme systems isolated from etiolated shoots of oat seedlings. The enzyme systems responsible for these reactions were partially purified and charaterized. Enzyme A appeared to be a multicomponent system, equally reactive with either cysteine or glutathione. Enzyme B was twice as active as enzyme A in the formation of S-cysteinyl-hydroxychlorpropham. Affinity chromatography of enzyme A produced an enzyme fraction with properties similar to those of enzyme B. Both enzymes (A and B) were significantly inhibited by increased cysteine concentrations. The reaction of glutathione with enzyme B was limited. However, when low concentrations of a nonreacting effector, cysteine ethyl ether, were added, glutathione conjugation increased significantly. At higher concentrations, cysteine ethyl ester formed a conjugate with 4-hydroxychlorpropham. Isopropyl-5′-chloro-2′-hydroxycarbanilate (2-hydroxy-5-chlorpropham) did not conjugate with either cysteine or glutathione but did react with cysteine ethyl ester. Isopropyl-3′-chlorocarbanilate (chlorpropham) was not a substrate for thioether conjugation. These data suggest that para- and/or ortho-hydroxylated carbanilates and cysteine-related substrates may form thioether conjugates when incubated under appropriate conditions with these complex enzyme systems.     

Inhibitory and promotive allelopathy in rice (Oryza sativa L.)

Studies on allelopathic rice, which inhibits the germination and development of weeds such as barnyardgrass ( Echinochloa spp.) and ducksalad [ Heteranthera limosa (Sw.) Wild.], have been strongly conducted in the USA, the Philippines, Japan, Korea, and other countries since the 1980s. Weed-suppressing rice plants can compete with weeds for light and mineral nutrients by their rapid and thick growth characteristics, and probably also by their allelopathic effects. It was suggested that allelopathic properties were inherited from parents. Different screening methods for finding allelopathic rice simply and rapidly have been proposed. In contrast, stimulative allelopathy in rice, which promotes germination of the dormant and dormancy-awakened seeds of Monochoria vaginalis (Burm. f.) Kunth var. vaginalis , has been investigated by the authors since the 1990s. Rice seeds promoted the germination in the dark and in light under submerged conditions. Our experiments suggested that rice seeds, hulls, plants and straw contain stimulative substance(s) that promote seed germination of M. vaginalis .     

Interaction between diclofop-methyl and 2,4-D in wild oat (Avena fatua L.) and cultivated oat (Avena sativa L.), and fate of diclofop-methyl in cultivated oat

Influence of 2,4-D on toxicity of diclofop-methyl to Avena sativa (cv. Selma) and Arena fatua at 2·5 leaf stage has been evaluated under controlled conditions. Effects of 2,4-D on the fate of diclofop-methyl in cultivated oat have also been studied. Mixture with 2,4-D reduced the toxicity of diclofop-methyl to both species. When applied immediately after diclofop-methyl treatment, 2,4-D still reduced herbicide toxicity to wild oat. This reduction was smaller in cultivated oat. and was only observed at higher phytotoxicity. No interaction was observed when a 10-day period separated the two applications. In mixture, 2,4-D enhanced diclofop-methyl penetration and diclofop acid conjugation in cultivated oat, and it slightly increased conjugation when applied separately. None of these effects clearly explain the reduction of diclofop-methyl toxicity by 2, 4-D in cultivated oat. Other processes are possibly involved and could be connected with the site of action of diclofop-methyl.     

Exogenously applied glycinebetaine induced alteration in some key physio-biochemical attributes and plant anatomical features in water stressed oat(Avena sativa L.) plants

Although exogenous application of glycinebetaine(GB) is widely reported to regulate a myriad of physio-biochemical attributes in plants under stressful environments including drought stress, there is little information available in the literature on how and up to what extent GB can induce changes in anatomical features in water starved plants. Thus, the present research work was conducted to assess the GB-induced changes in growth, physio-biochemical, and anatomical characteristics in two cultivars(CK-1 and F-411) of oat(Avena sativa L.) under limited water supply. After exposure to water stress, a considerable reduction was observed in plant growth in terms of lengths and weights of shoot and roots,leaf mesophyll thickness, leaf midrib thickness, root cortex thickness, root diameter, stem diameter, stem phloem area, and stem vascular bundle area in both oat cultivars. However, water stress resulted in a significant increase in leaf total phenolics, hydrogen peroxide(H_2 O_2), ascorbic acid(AsA), GB contents,activities of enzymes(CAT, SOD and POD), total soluble proteins, leaf epidermis(abaxial and adaxial)thickness, bulliform cell area, sclerenchyma thickness, root endodermis and epidermis thickness, root metaxylem area, stem metaxylem area and stem sclerenchyma thickness in both oat cultivars.Foliar-applied 100 mM GB suppressed H_2 O_2 contents, while improved growth attributes, free proline and GB contents, activity of SOD enzyme, leaf abaxial epidermis thickness, leaf bulliform cell area, leaf midrib thickness, leaf sclerenchyma thickness, root cortex thickness, root endodermis, epidermis thickness,root stele diameter, stem diameter, stem epidermis thickness, stem metaxylem area, and stem phloem and vascular bundle area in both oat cultivars. For both oat cultivars, CK-1 was superior to F-411 in leaf abaxial epidermis thickness, leaf mesophyll, leaf sclerenchyma, root metaxylem area, stem diameter, stem epidermis, sclerenchyma thickness, stem metaxylem area, and stem vascular bundle area. Overall, both oat cultivars showed inconsistent behavior to water stress and foliar-applied GB in terms of different physio-biochemical attributes, however, CK-1 was superior to F-411 in a number of anatomical features of leaf, root, and stem.     

不同生长年限敖汉苜蓿草地土壤呼吸研究

使用便携式土壤呼吸测定仪测定农牧交错带1年、2年和4年生敖汉苜蓿人工草地的土壤呼吸,并同步测定0～5 cm土层的温度和含水量.结果表明:敖汉苜蓿草地土壤呼吸的日最高值出现在14:00-18:oo,夜间最高值出现在4:00-6:00,全天最低值出现在10:00左右;不同生长年限敖汉苜蓿草地的土壤呼吸速率,总体变化趋势是4年生>2年生>1年生;土壤呼吸与土层温度呈显著的指数增长关系,且相关性高于土壤呼吸速率与土壤含水量的相关性;5 cm土层的地温和土壤含水量较土壤温度或空气湿度能更好地解释土壤呼吸的变化.     

燕麦DNA导入普通小麦后代的同工酶酶谱分析

以健壮燕麦（Avera sativa L.)为供体，宁春4号小麦为受体，采用花粉管通道法进行外源DNA导入。对供体、受体及其D5代的变异株系进行酯酶同工酶和过氧化物酶同工酶分析表明：变异后代与亲本的谱带有明显差异，无论是在酯酶同工酶中还是在过氧化物酶同工酶中，均出现了供体特有的谱带；在过氧化物酶同工酶中既出现了供、受体均不具有的新的杂交酶带，有的还显现了偏父或偏母以及完全互补型的酶带；酶的活性也发生了很大变化。认为可以用同工酶分析作为鉴定外源DNA导入的生化指标之一。     

杂草稻落粒粳种子的耐冷性评价

采用低温处理方法评价了杂草稻落粒粳（Orayza sativaL.）种子的耐冷潜力。浸种0~48 h,落粒粳种子平均含水量为17.038%,显著低于栽培稻春江11的20.533%和赣早籼的20.180%,落粒粳颖壳具有比两种栽培稻更强的水分阻隔能力。在相同含水量条件下,经过低温-20℃处理3 h和28℃条件下培养4 d的落粒粳种子发芽率显著高于春江11和赣早籼,落粒粳种子具有更强的耐冷能力。     

野生稻、野燕麦、枸杞DNA的提取方法

采用CTAB法和2种经改进SDS法提取野生稻、野燕麦、枸杞总DNA。提取结果表明植物的种类不同,所适用的提取方法也有所不同。野生稻和野燕麦DNA提取较合适的方法为SDS-和CTAB法,枸杞DNA提取较合适的方法为SDS-法。     

Antagonistic effects of 2, 4-D), MCPA and MCPB on uptake and translocation of haloxyfop-ethoxyethyl in oat (Avena sativa L.)

The antagonism of haloxyfop-ethoxyethyl (HE) by selected phenoxy herbicides was evaluated through studies of the foliar absorption and translocation of ¹⁴C]HE in oat (Avena sativa L.). Uptake of [¹⁴C]HE, from simultaneous application in mixture with a phenoxy herbicide, was inhibited by the latter in the order MCPB MCPA2,4-D. In mixtures, the foliar absorption of [¹⁴C]HE was reduced more by salts of the phenoxy herbicides than by the corresponding butyl esters. 2,4-D-butyl enhanced uptake of [¹⁴C]HE. The application rate of phenoxy herbicides (from 0.5 to 1.5 kg a.e. ha^?1) did not affect the uptake of [¹⁴]HE, but did influence translocation. Movement of [¹⁴C]herbicide out of the treated leaf was less than 5% of the total ¹⁴C applied; translocation was significantly reduced by all phenoxy herbicides and was antagonized most by 2,4-D-salt and least by MCPB-butyl. Phenoxy salts invariably reduced [¹⁴C]HE translocation more than the corresponding butyl esters. Prior application of phenoxy salts reduced uptake of [¹⁴C]HE, but this antagonism was reduced as the time interval between spray applications increased. Translocation of ¹⁴C out of the treated leaf was antagonized most by prior application of 2,4-D, and by phenoxy salt formulations. When applied up to 2 days after HE, phenoxy salts reduced uptake, but translocation of ¹⁴C was generally unaffected. Les effets antagonistes du 2,4-D, du MCPA et du MCPB sur la pénétration et la migration de l'haloxyfop-éthoxyéthyl dans l'avoine (Avena sativa L.) L'effet antagoniste de plusieurs herbicides de type phénoxy à l'égard de l'haloxyfopéthoxyéthyl (HE) a étéétudié dans des études de pénétration foliaire et de migration du [¹⁴C]HE chez l'avoine (Avena sativa L.) Lorsqu'il est appliqué en mélange avec un herbicide phénoxy, la pénétration du [¹⁴C]HE est inhibée dans l'ordre suivant: MCPB MCPA 2,4-D. La pénétration foliaire du [¹⁴C]HE était davantage réduite par les sels d'herbicides phénoxys que par les esters butyles correspondants. Le 2,4-D butyle augmentait la pénétration du [¹⁴C]HE. La dose d'herbicides phénoxys (de 0,5 à 1,5 kg m.a. ha^?1) n'affectait pas la pénétration de [¹⁴C]HE mais modifiait sa migration. La migration d'herbicide ¹⁴C hors de la feuille traitée était inférieure à 5 % de la radioactivité appliquée. Elle était significativement réduite par tous les herbicides phénoxys, le plus par le sel de 2,4-D et le moins par le MCPB-butyle. Les phénoxys sous forme de sels diminuaient toujours la migration du [¹⁴C]HE davantage que les esters butyles correspondants. Si l'application de phénoxys sous forme de sel précédait celle de [¹⁴C]HE, sa pénétration était réduite mais cet antagonisme était réduit lorsque l'intervalle de temps entre les deux applications était augmenté. La migration de ¹⁴C hors de la feuille traitée était le plus diminuée par le 2,4-D et par les phénoxys sous forme de sels. Quand ils étaient appliqués jusqu'à deux jours après [¹⁴C]HE, les phénoxys sous forme de sel réduisaient sa pénétration, mais la migration de ¹⁴C n'était généralement pas affectée. Antagonistische Wirkung von 2,4-D, MCPA und MCPB auf die Aufnahme und Translokation von Haloxyfop-ethoxyethyl in Hafer (Avena sativa L.) Die antagonistische Beeinflussung von Haloxyfop-ethoxyethyl (HE) durch ausgewählte Phenoxy-Herbizide wurde anhand der Blattaufnahme und Translokation von [¹⁴C]HE in Hafer (Avena sativa L.) untersucht. Die Aufnahme von [¹⁴C]HE bei gleichzeitiger Anwendung in Mischung mit einem Phenoxy-Herbizid wurde durch die letztgenannten Stoffe in der Reihenfolge MCPB MCPA 2,4-D gehemmt, wobei die Salz-Verbindungen stärker wirkten als die entsprechenden Butylester. 2,4-D-butyl förderte die Aufnahme von [¹⁴C]HE. Die Aufwandmenge der Phenoxy-Herbizide (0,5 bis 1,5 kg AS ha^?1) blieb ohne Einflus auf die Aufnahme von [¹⁴C]HE, beeinflußte aber die Translokation. Aus den behandelten Blättern wurde weniger als 5 % der gesamten [¹⁴C]Menge transloziert; die Translokation wurde durch alle PhenoxyHerbizide signifikant reduziert, am meisten durch 2,4-D-Salz, am wenigsten durch MCPB-butyl. Die Salz-Verbindungen verminderten die [¹⁴C]HE-Translokation mehr als die entsprechenden Butylester. Eine vorausgehende Behandlung mit den Salz-Verbindungen senkte die Aufnahme von [¹⁴C]HE, aber mit zunehmender Zeit zwischen den Anwendungen nahm dieser Antagonis mus ab. Hierbei war der Einfluß von 2,4-D und von den Salz-Verbindungen am stärksten. Wurden diese Stoffe bis zu 2 Tagen nach HE ausgebracht, beeinträchtigten sie die Aufnahme, jedoch im allgemeinen nicht die Translokation von ¹⁴C.     

紫花苜蓿下胚轴愈伤组织诱导及再生植株的研究

以培养4～5d的紫花苜蓿无菌苗的下胚轴为材料,改良SH(SH大量元素+MS微量元素+MS铁盐+UM有机)+水解酪蛋白(CH)2000 mg/L为基本培养基,对紫花苜蓿愈伤组织诱导和植株再生进行了研究。愈伤组织诱导和继代培养基分别为2,4-D 1.0 mg/L+KT 0.5 mg/L+蔗糖30 g/L及2,4-D 0.05 mg/L+BA0.5 mg/L+蔗糖30 g/L,将获得的愈伤组织转入正交设计的培养基上进行筛选,得到了愈伤组织分化率相对较高的培养基配方:基本培养基+KT 0.4 mg/L+蔗糖20 g/L,其分化率为73.0%。获得的再生芽在生根培养基上(1/2MSO)培养约10d便能获得具有根和叶的再生植株。本试验结果为下一步将来自蓝藻的Na⁺/H⁺ an-tiporter基因转入苜蓿,获得转基因耐盐苜蓿奠定了基础。     

Effect of different levels of mannitol-induced water stress on the tolerance of cultivated oat (Avena sativa L.) to didofop-methyl

The effect of degree of water stress in Avena sativa on diclofop-methyl efficacy was assessed. Within 24 h of applying stress by adding mannitol to the root medium (0 to 12.5%), the rate of leaf extension of the youngest leaves (leaves 3 and 4) decreased with increasing mannitol concentration. Without water stress, application of diclofop-methyl had little effect on extension rate of leaves 3 and 4 during the first 4 days after spraying. Subsequently, it caused a significant decrease in the extension rate of leaf 4 with more pronounced effects on later leaves. Diclofop-methyl had little effect on leaf extension rate of plants given mannitol. Shoot dry weight at harvest for unsprayed plants decreased with increased mannitol concentration and for sprayed plants it was greater without mannitol than with mannitol (all levels). However, at mannitol concentrations greater than 4%, shoot dry weight for sprayed and unsprayed plants was not significantly different. Sprayed plants exposed to 2–8.5% mannitol produced seed heads but those at zero mannitol did not. When the root medium of all treatments was flushed of mannitol one week after spraying, then main-tained without mannitol, shoot dry weight at harvest for unsprayed plants decreased slightly with increased mannitol concentration applied initially. However, shoot dry weight for sprayed plants increased with increased mannitol concentration. Without mannitol two weeks after spraying, chlorophyll concentrations of leaves 3 and 4 were greater and water saturation deficit (WSD) values were lower for unsprayed plants than sprayed plants but there were no differences at 6.2% mannitol. It is proposed that tolerance to diclofop-methyl by A. sativa as a result of water stress, is primarily due to a decreased rate of leaf expansion resulting in lower demand for membrane synthesis and less strain on membranes damaged by the herbicide.     

The influence of the nitrogen status of oat plants (Avena sativa L.) on the interception and retention of foliar sprays

Young oat plants grown at a high soil nitrogen level retained more spray than plants grown at a lower nitrogen level. The greater retention by the high nitrogen plants appeared to be due both to their greater leaf area and to the less vertical angle of the leaves. The angles of contact of water droplets on the leaf surfaces were lower for high nitrogen plants. Therefore water droplets hitting the surface of the leaves of these plants would be less likely to be reflected and would spread over the leaf surface more readily than droplets hitting the leaves of low nitrogen plants. These results are discussed in relation to earlier work which showed that high nitrogen plants were more susceptible than those grown at a low nitrogen level to the foliar-applied herbicide, paraquat. Influence de l'état de l'azote chez l'avoine (Avena Sativa L.) sur l'interception et la rétention des pulvérisations foliaires. De jeunes plantes d'avoine poussant sur un sol è teneur élevée en azote ont retenu plus de liquide pulvérisé que eetles poussant sur un sol è teneur en azote plus faible. La rétention plus grande, par les plantes soumises è un haut niveau d'azote, paraît être provoquée par la plus grande surface foliare et par la position moins verticale de leurs feuilles. Les angles d'arrivée des goutteleltes d'eau sur la surface des feuilles ont été plus faibles sur les plantes soumises è un niveau d'azote élevé. En conséquence, les goutlelettes d'eau frappant la surface de ces feuilles pourraient être vraisemblablement moins rejetées et seraient susceptibles de s'étaler sur la surface de la feuille plus aisément que celles qui frappent les feuilles des plantes soumises è un faible niveau d'azote. Ces résultats sont diseutés en relation avee un travail Préeédent qui a montré que les plantes soumises è un niveau d'azote élevéétevé plus sensibies au paraquat, herbicid applique sur les feuilles. que celles poussant è un faible niveau d'azote. Der Einfluss der Stickstoffernährung von Haferpflanzen (Avena sativa L.) auf die Retention von Blattspritztingen. Junge Haferpflanzen, die in einem stark mit Stiekstoff gedüngten Boden wuchsen, hielten mehr Spritzbrühe zurück als soehe, die bei mässiger Stickstoffversorgung wucbsen. Die grössere Retention bei den gut mit Stiekstofl” versorgten Pflanzen scheint auf ihre grössere Blattfläche und auf ihre weniger aufrechte Blattstellung zurückzuführen zu sein. Bei den gut mit Stiekstoff versorgten Pflanzen waren die Kontaktwinkel für Wassertröpfchen auf der Blatloberfläche kleiner. Deshalb dürften Wassertröpfchen die die Blattober-fläche solcher Pflanzen treffen in geringerem Masse zurück-prallen und dadureh sicb besser auf der Blattoberfläche ausbreiten als die Tröpfchen auf Blätter weniger gut mit Stickstoff versorgter Pflanzen. Diese Ergebnisse werden in Beziebung zu früheren Untersuehungen diskutiert, in deiien sich gezeigt hatte, dass mit Stickstoff gut versorgte Pflanzen gegen Blattspritzungen mit Paraquat empfindlicher waren, als Pflanzen die bei niedrigerem StickslofFniveau wuehsen.     

导入燕麦DNA的小麦后代光合特性及农艺性状变化的研究

健壮燕麦(AvenasativaL.)总DNA通过花粉管通道导入普通小麦宁春4号,变异品系的光合特性及农艺性状发生变化:部分变异品系的旗叶功能期以及叶绿素含量改变,光合速率加快;穗长、结实小穗数、主穗粒数增加,穗粒重提高。方差分析表明,各变异品系与受体之间的叶绿素含量、光合速率及主要农艺性状均有显著差异。相关分析显示:自灌浆期起,变异品系的叶绿素含量与光合速率呈极显著正相关,在灌浆初期,叶绿素含量、光合速率均与结实小穗数、主穗粒数、穗粒重呈显著正相关。上述结果显示将燕麦DNA导入普通小麦,有助于小麦综合性状的改善,丰富小麦育种材料。     

S-cysteinyl-hydroxychlorpropham: Formation of the S-cysteinyl conjugate of isopropyl-3′-chloro-4′-hydroxycarbanilate in oat (Avena sativa L.)

Isopropyl-3′-chlorocarbanilate (chlorpropham) forms phenolic metabolites, isopropyl-3′-chloro-4′-hydroxycarbanilate (I), and isopropyl-5′-chloro-2′-hydroxycarbanilate (II), in several plant species. In oat, which is a chlorpropham-susceptible plant, I was converted to an S-cysteinyl-conjugate (III). The reaction in vitro was catalyzed by a partially purified, soluble enzyme. The formation of III by the enzyme preparation and by oat shoot sections was compared. Mass spectral data indicated the presence of an aryl-thioether bond, and chloro-, hydroxy-, and isopropylcarbanilate groups in III. The results of this investigation indicate that III was isopropyl-[(2-amino-2-carboxyethyl)thio]-chloro-hydroxycarbanilate (S-cysteinyl-hydroxychlorpropham).     

Development and validation of a quantitative PCR assay method of assessing relative resistance of oat (Avena sativa) to crown rust (Puccinia coronata f. sp. avenae)

Evaluation of oat crown rust resistance is usually based on visual assessment of disease severity or infection types. Visual assessment is subjective, prone to rater bias and requires expert knowledge. PCR-based quantitative assays can overcome challenges associated with visual assessment. New TaqMan primers and probes were designed from Puccinia coronata f. sp. avenae (Pca) sequences. The primer–probe sets were specific to Pca, amplified using as little as 0.5 pg fungal DNA (fDNA) and allowed for scaling to variation in sample total DNA quantity. The quantitative PCR (qPCR) assay was validated using oat recombinant inbred lines (RILs) from the Provena × 94197A1-9-2-2-2-5 cross evaluated under a controlled environment. For comparison with fDNA load, inoculation with the Pca race LCBB provided segregation data on the hypersensitive response, while Pca race LSLG provided data on segregation for reduced pustule number. fDNA content was positively correlated with both pustule number and infection type (IT). Composite interval mapping identified two quantitative trait loci (QTLs) on oat linkage groups Mrg12 and Mrg20 using visual and qPCR assessments (pustule number, IT and fDNA). In this study a qPCR assay method that can be used to assess the relative resistance of oat to crown rust was refined and validated, and single nucleotide polymorphisms (SNPs) closely linked with two QTLs derived from the crown rust resistant line 94197A1-9-2-2-2-5 were identified.