Frank Marthe

Chromosome number and ploidy level of balm (Melissa officinalis)

BackgroundLemon balm (Melissa officinalis L.) is of increasing importance resulting in rising growth area. Improved knowledge on the genome structure, number of chromosomes in connection with the taxonomical structure of balm is indispensable for improved new varieties.ResultsA collection of 40 balm accessions (M. officinalis) was characterized by flow cytometry and FISH (18/25S and 5S rDNA) to determine the chromosome number and ploidy level. Three different types were found: diploid genotypes with 2n = 2× = 32 chromosomes; tetraploid 2n = 4× = 64 chromosomes and triploid 2n = 3× = 48 chromosomes. A haploid base number of × = 16 chromosomes is likely. First time described triploid accessions are sterile but cytologically and morphologically stable for many years. Triploids express better winter hardiness and regeneration after harvesting cuts as well as bigger leaves and internodes.ConclusionsA basic chromosome number of x = 16 is reported for the first time for the species M. officinalis.AbstractDie wachsende Bedeutung von Zitronenmelisse (Melissa officinalis L.) führt zur Ausdehnung des hierfür erforderlichen Anbauumfanges. Ein verbesserter Kenntnisstand der Genomstruktur, der Chromosomenzahl und der hiermit in Zusammenhang stehenden taxonomischen Struktur der Melisse sind unerlässliche Voraussetzungen für verbesserte, neue Sorten.Eine Kollektion von 40 Melisseherkünften (M. officinalis) wurde durchflusszytometrisch und durch FISH (18/25S and 5S rDNA) untersucht, um den Ploidiegrad und die Chromosomenzahl zu ermitteln. Drei unterschiedliche Typen wurden konnten bestimmt werden: diploide Genotypen mit 2n = 2× = 32 Chromosomen; tetraploide mit 2n = 4× = 64 Chromosomen und triploide mit 2n = 3× = 48 Chromosomen. Die haploide Chromosomenzahl ist mit x = 16 anzunehmen. Die erstmalig beschriebenen triploiden Herkünfte sind steril aber zytologisch und morphologisch über viele Jahre stabil. Sie zeigen eine bessere Winterhärte und einen schnelleren Wiederaufwuchs nach Ernteschnitten, wie auch größere Blätter und Internodien.Die Basischromosomenzahl von x = 16 wird erstmalig für die Art M. officinalis beschrieben.

Sensory characteristics and volatile profiles of parsley ( Petroselinum crispum [Mill.] Nym.) in correlation to resistance properties against Septoria Blight ( Septoria petroselini ).

Sixteen different genotypes of parsley, including two cultivars, six populations, and eight inbred lines, were investigated regarding their sensory characteristics in relation to the volatile patterns and resistance to Septoria petroselini . The sensory quality was determined by a combination of profile analysis and preference test, whereas the volatile patterns were analyzed by headspace-SPME-GC of leaf homogenates with subsequent nontargeted data processing to prevent a possible overlooking of volatile compounds. The more resistant genotypes are characterized by several negative sensory characteristics such as bitter, grassy, herbaceous, pungent, chemical, and harsh. In contrast, the contents of some volatile compounds correlate highly and significantly either with resistance (e.g., hexanal and α-copaene) or with susceptibility (e.g., p-menthenol). Some of these compounds with very strong correlation to resistance are still unidentified and are presumed to act as resistance markers.

Verbesserung der Krankheitsresistenz von Kohlgemüse: 1. Turnip mosaic virus(TuMV)

Zusammenfassung:Das Turnip mosaic virus (TuMV) ist weltweit verbreitet und gehört zur Gruppe der Potyviren. Es hat einen außerordentlich großen Wirtspflanzenkreis von über 300 Arten und wird nicht persistent durch 89 Aphidenarten übertragen. Bisher sind beim TuMV zwölf Pathotypen bekannt. Im Kohlgemüse verursacht das TuMV die so genannte Kohlschwarzringfleckigkeit. Dabei handelt es sich um eine wirtschaftlich wichtige Virose, die beim Weißkohl bis zu 25 % Ertragsausfall und Gewebenekrotisierungen, insbesondere während der Kühllagerung, bewirken kann. Zur Sicherung eines hohen Ertrags- und Qualitätsniveaus bei Kohlgemüse wurde begonnen, die Resistenz gegen diese Virose zu verbessern. Mit aktuellen, weitgehend charakterisierten Erregerherkünften des TuMV wurden Resistenzprüfmethoden weiterentwickelt und neue Resistenzquellen in der Familie der Brassicaceae erschlossen. Resistenzen gegen mehrere TuMV-Pathotypen ließen sich in B. oleracea-Primitivformen, in Chinakohl (B. rapa ssp. pekinensis), in Meerrettich (Armoracia ru-sticana), in Radies bzw. Rettich (Raphanus sativus) sowie in sexuell erzeugten Raphanobrassica-Hybriden nachweisen. Die evaluierten TuMV-Resistenzen wurden entsprechend der phylogenetischen Distanz zum Kohl durch Kreuzung bzw. durch Protoplastenfusion in Kulturformen des Kohls übertragen.Summary:Turnip mosaic virus (TuMV) is an important pathogen in vegetable Brassica crops and belongs to the Potyvirus group. The virus occurs worldwide and has a very wide host range of more than 300 plant species including different Brassica crops. In white cabbage (Brassica oleracea var. capitata) TuMV infection causes up to 25 % yield reductions as well as necrosis during cold storage of the heads. An effective way of plant protection is the establishment of resistance to different TuMV pathotypes in cabbage.TuMV isolates were characterized and resistance screening methods utilizable under greenhouse and field conditions were developed. The search for resistance to TuMV in more than 100 accessions of the Brassicaceae family revealed some new resistance donors. Resistance to different TuMV pathotypes was found in B. oleracea primitive forms, Chinese cabbage (B. rapa ssp. pekinensis), horse-radish (Armoracia rusticana) and radish (Raphanus sativus). A high level of resistance to three TuMV pathotypes was also detected in sexually developed Raphanobrassica hybrids. In a B. oleracea landrace five inbred lines (I6) were selected under field conditions receiving a high level of resistance (infection rate 0 %) after inoculation with the high virulent TuMV isolate 2. From two B. oleracea primitive forms seven homozygous lines (I5) were developed by successive selection and self-pollination. After inoculation with five TuMV isolates representing three pathotypes (Mix 1), resistant plants were symptom-less as well as DAS-ELISA negative. Resistance to TuMV in B. oleracea primitive forms could be transferred into white cabbage by crosses followed by successive screening and selection procedures. Somatic hybrids between R. sativus and B. oleracea resistant to TuMV were generated by protoplast fusion.

Comparison of in vitro haploid induction in balm (Melissa officinalis)

The generation of haploids in lemon balm (Melissa officinalis L.) is the prerequisite for accelerated development of homozygous lines. Wide experiments to induce sporophytic development were arranged. Donor plants of lemon balm were established in a greenhouse, climate chambers and in vitro. For haploid induction, different variations of media and culture conditions e.g. pretreatment with cold and heat were tested. Sporophytic development of pollen was induced in anther and microspore culture. Callus developed sporadically in anther culture. Multi-cellular structures and microcallus generated from microspores. In vitro cultivated ovules became dark brown and somatic callus generated at the cut surface. Cultivation of ovaries maintained swelling on medium, but undeveloped embryos died.

Verbesserung der Krankheitsresistenz von Kohlgemüse: 2. Kohlhernie, Alternaria- und Phoma-Blattfleckenkrankheit

Zusammenfassung:Kohlhernie (Plasmodiophora brassicae), Schwarzfleckigkeit (Alternaria brassicicola, A. brassicae) sowie die durch Phoma lingam verursachte Blattfleckigkeit und Fußvermorschung sind wirtschaftlich bedeutsame Erkrankungen des Kohlgemüses. Für ihre Begrenzung bietet sich als Alternative zum Einsatz von Fungiziden die Nutzung der erblichen biotischen Resistenz im Wirt an. Bei Darlegung eigener Untersuchungsergebnisse werden Informationen zum Stand der Evaluierung von Resistenzträgern und dem Resis- tenztransfer in Kulturformen von Brassica oleracea durch konventionell züchterische sowie moderne In-vitro-Verfahren gegeben. Bei der Kohlhernie bestehen gute Aussichten, stabile Resistenzen insbesondere durch Nutzung quantitativ-genetischer Erbfaktoren (vornehmlich rezessive Anlagen, additive und Domi-nanzeffekte) zu entwickeln. Dagegen stellt sich die Situation bei den Alternarien und Phoma lingam als wesentlich komplizierter dar, da effektive Resistenzen nur in mehr/weniger systematisch weiter von B. oleracea entfernten Taxonen präformiert sind. Diese müssen zunächst durch moderne biotechnologische Verfahren in die Kulturformen übertragen, in Bezug auf den Vererbungsmodus charakterisiert und später in fertilen Genotypen durch genetisch-cytologische und züchterische Maßnahmen etabliert und stabilisiert werden. Erste Erfolge zur Übertragung von Phoma-Resistenz in Kohl liegen vor.Summary:Clubroot (Plasmodiophora brassicae), black leaf spot (Alternaria brassicicola, A. brassicae) as well as leaf spot and blackleg caused by Phoma lingam are economically important diseases in Brassica vegetables. For their control, the utilisation of inheritable biotic resistance in the host is an alternative to the application of fungicides. Results of resistance evaluation and transfer of resistance into culture forms of Brassica oleracea by conventional breeding and modern in vitro techniques are presented. Concerning clubroot there are good chances for establishing durable resistance particularly by using quantitative inheritance factors. With regard to the Alternarias and Phoma lingam the situation is more complicated because effective resistance traits only occur in taxa more/less distantly related to B. oleracea. These traits must, first of all, be transfered into the culture forms by modern biotechnological techniques (protoplast fusion, gene transfer), characterized with regard to the mode of resistance in heritance and, thereupon, established and stabilised by genetic, cytogenetic and breeding arrangements in fertile genotypes. First successful attempts in transferring Phoma-resistance into cabbage have been performed.

Variability in parsley (Petroselinum crispum [Mill.] Nyman) for reaction to Septoria petroselini Desm., Plasmopara petroselini Săvul. et O. Săvul. and Erysiphe heraclei DC. ex Saint-Aman causing Septoria blight, downy mildew and powdery mildew

A collection of 220 accessions of parsley (Petroselinum crispum [Mill.] Nyman) was evaluated at two experimental stations (Gatersleben and Quedlinburg, Germany) under natural infection. Widespread origins of tested accessions provide the opportunity for first-time characterization of existence, spreading and level of resistance/susceptibility to the economically important pathogens Septoria petroselini Desm., Plasmopara petroselini Săvul. et O. Săvul. and Erysipheheraclei DC. ex Saint-Aman causing Septoria blight, downy mildew and powdery mildew respectively throughout the species P. crispum. For each pathogen, accessions free or nearly free of symptoms were found: S. petroselini: free 1, nearly free 25, P. petroselini: free 51, nearly free 22 and E. heraclei: free 166. Eight accessions are free or nearly free of symptoms for all three pathogens: PET36, PET169, PET172, PET177, PET178, PET192, PET212 and PET214. The accession PET16 is free of symptoms for both S. petroselini and P. petroselini. Most of the resistant material comes from Southern and Eastern Europe. There could be a centre for resistances of parsley.