The relation between soil water tension and rate of development of the eggs of Tipula oleracea and T. paludosa (Diptera, Nematocera)

The mean incubation time in control conditions (saturated blotting paper with pF less than ) was 6.18 days for T. oleracea and 11.0 days for T. paludosa at a temperature of 20°. Fertile T. paludosa eggs increased their weight by just over half between the ages of two and three days. Both fertile and infertile T. oleracea eggs increased weight by about a fifth in the first ten minutes and fertile ones further increased by just over half between the ages of 36 and 48 hours. Eggs on soil of pF values up to 3.6 developed at a similar rate to eggs in control conditions while development at pF 4.2 took longer. The duration of the mid-incubation swelling was not affected by pF up to the value of pF 3.6 but was longer at pF 4.2. The logarithm of the duration of the initial weight increase of T. oleracea varied in direct proportion to pF between values of pF 0.8 and 4.2.

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Zusammenfassung Eine Methode zur Messung der Entwicklungsgeschwindigkeit der Eier bei 20±5° und einem pF (= log cm Wasserdruck) von wird beschrieben.Die durchschnittliche Entwicklungsdauer der Eier betrug unter Kontrollbedingungen (auf gesättigtem Löschpapier bei pF ) 6,18 (T. oleracea) oder 11,0 Tage (T. paludosa). Befruchtete Eier von T. paludosa vermehren im Alter von 2–3 Tagen ihr Gewicht um ungefähr die Hälfte. Befruchtete und unbefruchtete Eier von T. oleracea erhöhten ihr Gewicht in den ersten 10 Minuten um etwa ein Fünftel und befruchtete vergrößerten es im Alter von 36–48 Stunden weiter um ungefähr die Hälfte.Auf Erde bei pF bis 3,6 entwickeln sich die Eier mit ähnlicher Geschwindigkeit wie unter Kontrollbedingungen. Bei pF 4,2 dauerte die Entwicklung bedeutend länger. Die Dauer der Eischwellung im mittleren Entwicklungsstadium blieb bis zu pF 3,6 gleichfalls unverändert, war aber bei pF 4,2 bedeutend länger. Die Dauer der anfänglichen Gewichtserhöhung der Eier von T. oleracea wechselt mit dem pF. Der Logarithmus der Dauer der Initialgewichtszunahme ändert sich in direkter Abhängigkeit zum pF zwischen den Werten 0,8 und 4,2.

     

The relation between soil water tension and growth rate of larvae of Tipula oleracea and T. paludosa (Diptera) in turf

Growth rates were determined at pF values ranging from less than to 4.2, with the turf being kept as near as possible in the natural state (i.e. with living grass etc.). Growth rates of first, third and fourth instar larvae were found and were usually highest at pF 0.8 and nearly zero at pF 4.2. Growth rates (fourth instars) or log growth rates (first and third instars) varied in inverse proportion to pF between values of pF 0.8 and 4.2. There was generally no difference between growth rates of larvae at pFs 0.8 and .Water gain and loss over the general cuticular surface was measured in T. paludosa third instar larvae kept in sucrose solutions with osmotic pressures equivalent to certain pF values. Rate of weight change per unit surface area varied with the external osmotic pressure, being positive below 6 Atmospheres (equivalent to pF 3.77) and negative above. Larvae growing in turf of pF above 3.77 therefore have to obtain water from the food for the whole of the water component of their net weight increase and also balance water loss through the cuticle.

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Zusammenfassung Die Wachstumsraten wurden bei Feuchtigkeitswerten zwischen pF<1,0 und 4,2 bestimmt, wobei die Rasenstücke in einem möglichst naturnahen Zustand, d.h. mit lebendem Gras usw. gehalten wurden. Die Wachstumsraten des 1., 3. und 4.Larvenstadiums wurden festgestellt und waren gewöhnlich bei pF 0,8 am höchsten und bei pF 4,2 nahe Null. Die Zuwachsraten (der 4.Larvenstadien) oder die Logarithmen der Zuwachsraten (der 1. und 3.Stadien) variierten im umgekehrten Verhältnis zu den pF-Werten von 0,8 bis 4,2. Es bestanden im allgemeinen keine Unterschiede in den Wachstumsgeschwindigkeiten bei pF-Werten zwischen 0,8 und 1,0.Bei Larven des 3.Stadiums von T. paludosa, die in Rohrzucker-Lösungen mit äquivalentem osmotischen Druck bestimmter pF-Werte gehalten wurden, wurde Wasseraufnahme und-abgabe durch die allgemeine kutikulare Oberfläche gemessen. Die Geschwindigkeit der Gewichtsveränderung pro Flächeneinheit änderte sich mit dem osmotischen Außendruck und war bei Drucken unter 6 atü (pF 3,77) positiv und darüber negativ. Larven, die sich in Rasen mit pF über 3,77 entwickeln, müssen deshalb nicht nur den gesamten Wasseranteil ihres Nettogewichts-Zuwachses, sondern auch zum Ausgleich von Wasserverlusten durch die Kutikula Wasser aus der Nahrung erhalten.

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羽衣甘蓝对镉的耐性和富集特征研究

以观赏绿化植物羽衣甘蓝(Brassica oleracea L.var.acephala DC.)为试验材料,采用盆栽试验,研究其对镉的耐性和富集特征,探讨羽衣甘蓝对镉污染土壤生物修复的可行性。结果显示:(1)随着镉处理浓度的增加,羽衣甘蓝干重呈先升高后降低的趋势,20~80mg·kg-1镉处理能促进植株的生长,100~120mg·kg-1镉处理虽然显著抑制了根系的生长,但是促进了地上部的生长,整体而言对全株生长无明显影响,表明羽衣甘蓝对镉有较强的耐性,且地上部的耐性高于根系。(2)所有镉处理下,羽衣甘蓝叶片的SOD、POD和APX活性较高,MDA含量和电解质渗漏率与对照无差异;而镉处理浓度高于80mg·kg-1时,根系的SOD、CAT和APX活性显著降低,MDA含量和电解质渗漏率显著升高,引起严重的膜脂过氧化伤害,这可能是羽衣甘蓝地上部的镉耐性高于根系的原因之一。(3)羽衣甘蓝地上部的镉含量高于根系,且随着镉处理浓度的增加均逐渐增加,在镉处理浓度为120mg·kg-1时达到最大值,分别为50.15mg·kg-1(根系)和52.01mg·kg-1(地上部);植株对镉的转运系数大于1,地上部镉富集量高于根系,地上部最大富集量为每株343.19μg。研究表明,羽衣甘蓝对镉有很强的耐性和富集、转运能力,是一种良好的修复镉污染土壤的观赏绿化植物资源。     

StP5CS基因转化结球甘蓝的研究

为研究StP5CS基因在结球甘蓝中的耐盐作用,以结球甘蓝下胚轴为外植体,采用农杆菌介导法将耐盐基因StP5CS和抗除草剂Bar基因导入结球甘蓝基因组中,在双丙氨膦的筛选下扩繁、生根,共获得了36株抗性植株。PCR扩增和Southern印迹杂交检测表明:目的基因StP5CS和Bar基因已经成功导入结球甘蓝基因组中。RT-PCR检测表明:StP5CS基因在转录水平也有表达。转基因植株耐盐试验结果显示:高浓度盐处理(400mmol/L NaCl)下,对照植株整株枯死,而转基因植株仍能正常生长;转基因植株的SOD活性、脯氨酸含量和相对膜透性均随盐浓度的升高呈上升趋势,均在400mmol/L NaCl处理下达到最大。结果表明转基因植株对高盐环境有一定的耐受性。     

菠菜性别相关的ISSR标记

菠菜为雌雄异株植物,用CTAB法提取其雌、雄株成株幼嫩叶片DNA,分别构建雌、雄株DNA池,以之为模板,用已优化的ISSR体系扩增,在74条ISSR引物中,I62扩增出一条约1 200 bp雌性连锁标记,回收纯化该特异扩增片段,将其连接于pUCm-T载体,转化进大肠杆菌JM109菌株,并检测及测序。回收克隆和测序后发现该片段全长1 176 bp,富含AT,AT占57.0%。根据测序结果设计1对25 bp的特异引物将这个雌性连锁的ISSR标记转化为稳定性和特异性更好的SCAR标记。该特异引物对随机选取的雌雄菠菜单株进行PCR扩增,在雌株中均有1 176 bp的特异条带,而雄株中均无。此特异条带的获得为菠菜性别相关基因的克隆奠定基础。     

结球甘蓝下胚轴原生质体培养再生植株体系的优化研究

以结球甘蓝‘新夏50’的无菌苗下胚轴为材料,对影响原生质体分离、纯化与培养的主要因素进行研究,建立适合结球甘蓝原生质体游离、纯化、收集、培养以至再生出完整植株的实用技术体系,为其非对称细胞融合及品种改良与创新等研究奠定基础。结果表明:2.5%纤维素酶R-10+0.05%果胶酶Y-23+9CPW+5mmol/L MES的混合酶液,从4d苗龄的下胚轴上分离出高产率的原生质体。在改良B5+0.5mg/L 2,4-D+0.2mg/L 6-BA+0.2mg/L NAA的液体培养基上,原生质体分裂旺盛。形成愈伤组织后经芽诱导和生根培养,获得了再生植株。倍性检测结果表明,不同原生质体所获得的24株再生植株中,19株为正常二倍体,4株为嵌合体,1株为四倍体。     

Karyotyping of Brassica oleracea L. based on rDNA and Cot -1 DNA fluorescence in situ hybridization

To explore an effective and reliable karyotyping method in Brassica crop plants, Cot-1 DNA was isolated from Brassica oleracea genome, labeled as probe with Biotin-Nick Translation Mix kit, in situ hybridized to mitotic spreads, and where specific fluorescent bands showed on each chromosome pair. 25S and 5S rDNA were labeled as probes with DIG-Nick Translation Mix kit and Biotin-Nick Translation Mix kit, respectively, in situ hybridized to mitotic preparations, where 25S rDNA could be detected on two chromosome pairs and 5S rDNA on only one. Cot-1 DNA contains rDNA and chromosome sites identity between Cot-1 DNA and 25S rDNA was determined by dual-colour fluorescence in situ hybridization. All these showed that the karyotyping technique based on a combination of rDNA and Cot-1 DNA chromosome landmarks is superior to all but one. A more exact karyotype of B. oleracea has been analyzed based on a combination of rDNA sites, Cot-1 DNA fluorescent bands, chromosome lengths and arm ratios. __________ Translated from Journal of Wuhan University (Nat. Sci. Ed.), 2006, 52(2): 230–234 [译自: 武汉大学学报 (理学版)]     

Biology of Tipula paludosa; Growth of the larva in the field

Tipula paludosa has an annual life cycle. The larval stage lasts from September to the following August. Larvae were collected from 16 fields in Northumberland and Cumberland at all times of year in the 10-year period 1954–1963. Larvae were individually weighed. The weights were used a) to construct curves showing the course of growth through the year and b) to compare average size of individuals from different places and different years.A growth curve was also constructed from the weights of larvae kept in the field under semi-natural conditions. Larvae grow extremely fast in the autumn, slowly through the winter and moderately fast in the spring and early summer.First instar larvae are present for only a few weeks in the autumn. Second and third instars are usually present in the population throughout the winter. Most larvae undergo the third moult in a restricted period in the spring just after the soil begins to warm up.The weight of larvae at the third moult is a convenient index of size of individual. Variation in mean weight between place-years was not significantly greater than variation within each field. Peak weight of larvae, on the other hand, did vary significantly from year to year though probably not from place to place in any one year. Pupal weight figures showed that females varied more than males from year to year. Since pupal weight is positively correlated with fecundity, larval spring growth is of importance in determining the number of eggs laid the following autumn. However, it is suggested that, from an economic point of view, the correlation between size and pasture damage is of more interest.

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Zusammenfassung Tipula paludosa Mg. hat einen einjährigen Lebenszyklus. Das Larvenstadium dauert von September bis zum nächsten August; denn Larven wurden während einer Periode von 10 Jahren, 1954–1963, von 16 Feldern in Northumberland und Cumberland zu allen Jahreszeiten gesammelt. Die Larven wurden individuell gewogen. Die Gewichte wurden verwendet a) zur Konstruktion von Kurven, welche den Wachstumsverlauf während des Jahres zeigen, und b) zum Vergleich der Durchschnittsgröße von Einzelticren verschiedener Orte und Jahre.Desgleichen wurde eine Wachstumskurve aus den Gewichten von Larven konstruiert, welche unter halb-natürlichen Bedingungen im Felde gehalten wurden. Die Larven wachsen im Herbst äußerst schnell, während des Winters langsam und im Frühling und Frühsommer mäßig schnell.Larven im ersten Stadium gibt es nur einige Wochen im Herbst. Larven im zweiten und dritten Stadium finden sich gewöhnlich den ganzen Winter hindurch in der Population. Die meisten Larven erleben die dritte Häutung in einem beschränkten Zeitraum im Frühjahr, gerade nachdem der Boden anfängt sich zu erwärmen.Das Gewicht der Larven bei der dritten Häutung ist ein bequemer Index für die Größe der Individuen. Die Variation im Durchschnittsgewicht zwischen Orten und Jahren war nicht viel größer als die Variation innerhalb jedes Feldes. Andererseits variierten die Spitzengewichte der Larven von cinem Jahr zum anderen bedeutend, aber wahrscheinlich nicht von Ort zu Ort in irgendeinem Jahr. Puppengewichtsziffern zeigten, daß die Weibchen von Jahr zu Jahr mehr variierten als die Männchen. Da Puppengewicht und Fruchtbarkeit in einer festen Beziehung zueinander stehen, ist das Larvenwachstum im Frühjahr wichtig zur Prognose der Eizahlen, welche im nächsten Herbst gelegt werden. Es wird jedoch darauf hingewiesen, daß vom wirtschaftlichen Standpunkt die Wechselbeziehung zwischen Größe und Weideschaden von größerer Bedeutung ist.

     

羽衣甘蓝裂叶相关性状遗传分析

以羽衣甘蓝圆叶自交系‘0835’和裂叶自交系‘0819’为亲本,调查P1、P2、F1、F2群体莲座期4个裂叶相关性状表型数据,运用‘四世代主基因+多基因’遗传模型,对叶长、叶宽、叶形指数、叶缘缺刻数4个叶形相关性状进行遗传分析,探讨羽衣甘蓝裂叶相关性状的遗传规律,为羽衣甘蓝裂叶性状遗传、QTL定位及新品种选育奠定基础。结果表明:(1)4个性状均存在一定的杂种优势,其中叶缘缺刻数中亲优势达显著水平,4个性状均存在负向超亲优势。(2)叶长和叶宽均符合E-4模型,即由2对等加性主基因+加性-显性多基因共同控制;叶长主基因遗传率为83.80%,多基因遗传率为1.05%;叶宽主基因遗传率为22.28%,多基因遗传率为61.92%。(3)叶形指数和叶缘缺刻数均符合E-1模型,即由2对加性-显性-上位性主基因+加性-显性多基因控制;叶形指数主基因遗传率为93.73%,多基因遗传率为2.59%;叶缘缺刻数主基因决定了表型变异的91.18%。     

马齿苋内生菌橘青霉和波兰青霉中抗青枯菌的活性物质

为了挖掘农作物病害生物防治新资源,以药用植物马齿苋(Portulaca oleracea)为材料,通过培养基种植法分离和纯化其根、茎、叶中的内生菌,以青枯菌(Ralstonia solanacearum)的抑菌试验评价其活性,采用菌落形态观察和ITS序列分析鉴定菌种。结果表明,从马齿苋筛选出2种具有抑制青枯菌的内生菌橘青霉(Penicillium citrinum)和波兰青霉(P. polonicum),采用液相与四极杆飞行时间串联质谱(UPLC-QTOF-MS)鉴定2种内生菌的主要活性物质为橘霉素,其对青枯菌的抑制效果比链霉素更好。因此,这为植物青枯病的生物防治提供科学依据。     

Carrageenan oligosaccharides enhance stress-induced microspore embryogenesis in Brassica oleracea var. italica

Embryogenic induction in cultures of isolated microspores is a stress-dependent process, which can be triggered by heat shock, sucrose or nitrogen starvation or by anti-microtubular drugs. As they are known to mimic biotic stress, oligosaccharides were tested as an alternative source of compounds to induce microspore embryogenesis in Brassica oleracea var. italica. Among the eight oligosaccharide series that were investigated and the corresponding polysaccharides, namely pectin, alginate, fucan, laminarin, agar and κ-, ι-, and λ-carrageenans, only the carrageenan oligomers displayed significant effects on microspore induction. When supplied in combination to heat stress, they markedly enhanced the final yields of microspore-derived embryos, with a two-fold increase in the most reactive treatment, i.e. in the presence of λ-carrageenan oligosaccharides. A 30 min treatment was enough to stimulate embryogenesis, and two optimal concentrations were observed, 170 nM and 34 μM.     

Biological control of Tipula paludosa (Diptera: Nematocera) using entomopathogenic nematodes (Steinernema spp.) and Bacillus thuringiensis subsp. israelensis

Tipula paludosa (Diptera: Nematocera) is the major insect pest in grassland in Northwest Europe and has been accidentally introduced to North America. Oviposition occurs during late August and first instars hatch from September until mid-October. Laboratory and field trials were conducted to assess the control potential of entomopathogenic nematodes (EPN) (Steinernema carpocapsae and S. feltiae) and Bacillus thuringiensis subsp. israelensis (Bti) against T. paludosa and to investigate whether synergistic effects can be exploited by simultaneous application of nematodes and Bti. Results indicate that the early instars of the insect are most susceptible to nematodes and Bti. In the field the neonates prevail when temperatures tend to drop below 10 °C. S. carpocapsae, reaching >80% control, is more effective against young stages of T. paludosa than S. feltiae (<50%), but the potential of S. carpocapsae might be limited by temperatures below 12 °C. Mortality of T. paludosa caused by Bti was not affected by temperature even at 4 °C but the lethal time increased with decreasing temperatures. Synergistic effects of Bti and EPN against T. paludosa were observed in 3 out of 10 combinations in laboratory assays but not in a field trial. The potential of S. carpocapsae was demonstrated in field trials against early instars in October reaching an efficacy of >80% with 0.5 million nematodes m⁻² at soil temperatures ranging between 3 and 18 °C. Results with Bti were strongly influenced by the larval stage and concentration. Against early instars in autumn between 74 and 83% control was achieved with 13 kg ha⁻¹ Bti of 5,700 International Toxic Units (ITUs) and 20 kg ha⁻¹ of 3,000 ITUs. Applications in spring against third and fourth instars achieved between 0 and 32% reduction. The results indicate that application of Bti and nematodes will only be successful and economically feasible during the early instars and that the success of S. carpocapsae is dependent on temperatures >12 °C. Synergistic effects between S. carpocapsae and Bti require more detailed investigations in the field to determine maximal effect.     

Spinacia oleracea L. protects against gamma radiations: a study on glutathione and lipid peroxidation in mouse liver

The present study deals with the protective effect of Spinacia oleracea L. against radiation-induced oxidative stress, which is evaluated in terms of lipid peroxidation (LPO) product and tissue levels of glutathione. Swiss albino male mice aged 6–8 weeks, weighing 22±3 g, each were selected from an inbred colony and divided into four groups. One group served as normal and a second group (extract of S. oleracea L. (SE) treated un-irradiated) were administered methanolic (50%) SE at a dose of 1100 mg/kg body wt./day dissolved in distilled water. A third group (untreated-irradiated) was administered distilled water orally, which served as control. A fourth group (SE pre-treated irradiated) was administered methanolic (50%) SE at a dose of 1100 mg/kg body wt./day dissolved in distilled water. Two groups, one untreated-irradiated and another S. oleracea pre-treated irradiated were exposed to 5 Gy of gamma radiation at a rate of 1.07 Gy/min with a source-to-surface distance of 77.5 cm. The animals were autopsied at 1, 3, 7, 15, and 30 days post-exposure. LPO increased after irradiation up to day 15 in the untreated-irradiated group and up to day 7 in SE pre-treated irradiated mice. LPO values were significantly lower in the SE pre-treated irradiated group as compared to their respective untreated-irradiated group at all intervals, which reached normal values from day 7 onward. The percentage of protection observed in the SE pre-treated irradiated group was, 22.22%, 24.8%, 33.25%, 42.84% and 26.36% at 1, 3, 7, 15, 30 days post-exposure, respectively. Radiation-induced glutathione depletion was checked after 7 days’ exposure in SE pre-treated irradiated as compared to untreated-irradiated in which recovery started after day 15. Values were significantly higher in the SE pre-treated irradiated group from their respective untreated-irradiated group at all intervals. The percentage of protection observed in the SE pre-treated irradiated group was, 29.41%, 42.68%, 43.55%, 53.81%, 39.28% at 1, 3, 7, 15, 30 days post-exposure, respectively. It is found that radiation-induced augmentation in malondialdehyde contents and depletion in glutathione changes in liver can be altered by S. oleracea L. The protection may be attributed to the combined effects of its constituents rather than to any single factor as the leaves are rich in carotenoid content (β-carotene, lutein, Zeaxanthine), ascorbic acid, flavonoids and p-coumaric acid. Thus Spinacia, showing protection in liver, may prove promising as a rich source of antioxidants because its use is cost-effective, especially for peoples in adverse and hazardous circumstances who are living in poverty.     

青花菜谷胱甘肽-S-转移酶基因克隆及其表达分析

为探讨青花菜在模拟酸雨胁迫下谷胱甘肽-S-转移酶的表达变化,克隆了青花菜谷胱甘肽-S-转移酶基因(glutathione-S-transferase,GST)的cDNA序列全长,并进行了生物信息学和表达分析。结果表明:青花菜GST基因cDNA全长为915bp,开放阅读框为642bp,编码213个氨基酸,推测分子式为C1091H1719N289O306S5,分子量为23 940.7,没有跨膜螺旋区域和信号肽。系统进化树分析表明,该青花菜基因GST与芥菜的GST聚类关系最近。实时荧光定量PCR结果显示,在模拟酸雨胁迫下,GST基因的表达量在胁迫初期显著增大,随时间延长开始下降,表明其参与了青花菜抗酸雨的应答反应。     

Direct somatic embryogenesis from pericycle cells of broccoli (Brassica oleracea L. var. italica) root explants

Cotyledon, hypocotyl or root explants of 7-day-old broccoli seedlings were cultured on Murashige and Skoog (MS) agar or liquid medium supplemented with 1.0 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D). The frequency of direct somatic embryo formation was 100% when root explants were cultured in liquid medium. Histological analysis indicated that somatic embryos were initiated directly from the pericycle cell layers of root explants as early as 1 day after liquid culture. Genotype did not affect the frequency of somatic embryo formation or the number of somatic embryos per explant. All broccoli genotypes examined had 100% somatic embryo induction efficiency, and the number of somatic embryos per 0.8 mm root segment ranged from 22.9 in ‘Luhui’ to 26.0 in ‘Haizi’. The number of normally developed somatic embryos in culture increased with increasing 2,4-D concentration. Plantlet regeneration frequency was the highest (73.3%) when germinated plantlets were transferred to 1/2 strength MS agar medium containing 1.0 mg l⁻¹ 6-benzyladenine (BA). When regenerated plantlets were transferred to a greenhouse, approximately 75% survived and there were no morphological differences between regenerated plants and seed-derived controls. The protocols established in this study will benefit large-scale vegetative propagation and transformation-based genetic improvement of broccoli.     

基于转录组和代谢组分析马齿苋根茎叶中类黄酮代谢

为获取马齿苋(Portulaca oleracea)类黄酮相关成分及其合成酶基因信息,该实验以马齿苋根、茎和叶为材料,进行代谢组学和转录组学联合分析,并从中选取6个差异表达基因进行qRT-PCR验证分析.结果显示:(1)代谢组分析发现,在马齿苋根、茎和叶中共获得32个类黄酮相关化合物,包括3个异黄酮、8个黄酮醇、11个...     

Lanius collurio L. undLanius senator L.

Ohne ZusammenfassungMit Aufnahmen und Zeichnungen der Verfassers.     

Physical linkage of the SLG and SRK genes at the self-incompatibility locus of Brassica oleracea

Summary In Brassica oleracea, the pollen-stigma interaction of self-incompatibility is controlled by a single genetically defined locus designated S. Molecular studies have identified two genes that are tightly linked to the classically defined S locus: The S-Locus Glycoprotein (SLG) gene and the S-Receptor Kinase (SRK) gene. In previous RFLP linkage analyses with probes specific for SLG and SRK, we were unable to identify any recombination events between SLG, SRK, and self-incompatibility phenotype. In this paper, we use pulsed-field gel electrophoresis (PFGE) in conjunction with DNA blot analysis to characterize the S-locus region from two highly divergent self-incompatibility genotypes, S ₂ and S ₆. We establish the physical linkage of SLG and SRK in each genotype, and demonstrate that the two genes are separated by a maximum distance of 220 kb in the S ₆ genotype and 350 kb in the S ₂ genotype. Furthermore, a comparison of the data from the two genotypes reveals that a high level of polymorphism exists across the entire S-locus region.     

Methoxybrassenins A and B, sulphur-containing stress metabolites from Brassica oleracea var. Capitata

Two methoxybrassinin-related stress metabolites, named methoxybrassenins A and B, were isolated from Brassica oleracea var. capitata inoculated with Pseudomonas cichorii. Their structures have been elucidated by spectroscopic and chemical methods. The unusual NMR spectrum of methoxybrassenin B is also discussed in connection with its structure.