Glucosinolate profiles of disomic rapeseed-radish chromosome addition lines

Glucosinolatgehalte und Glucosinolatmuster einer kompletten Serie von neun disomen Raps-Rettich Chromo­somenadditionen (2n = 38 + 2, a bis i) wurden bestimmt und mit denen des Chromosomenspenders Rettich und des Chromosomenempfängers Raps verglichen. Der Effekt einzelner Rettichchromosomen im identischen Rapshintergrund erlaubte die chromosomale Zuordnung von Schritten der Glucosinolat-Biosynthese. Die Addi­tionslinie a wies den fünffachen Glucosinolatgehalt auf wie der Rapselter. Die rettichspezifischen Glucosinolate Glucoraphenin und Glucoerysolin wurden ausschließlich in der Additionslinie g nachgewiesen. In der Additions­linie i wurde außerdem Sinigrin nachgewiesen, welches in keinem der Eltern gebildet wird. Der Glucosinolatgehalt ist nicht mit der Resistenz gegenüber dem Rübenzystennematoden (Heterodera schachtii Schmidt) korreliert.    The glucosinolate (GSL) content and -profile of a complete series of nine disomic rapeseed-radish chromosome addition lines (2n = 38 + 2, a to i) was estimated and compared to that of radish as donor and rapeseed as recipient of the alien chromosomes. Modification of identical genetic rapeseed background by single radish chromosomes allows the assignment of GSL biosynthesis steps to individual radish chromosomes. Addition line a was found to have a five times higher aliphatic GSL content than the rapeseed parent. Radish-specific GSLs, glucoraphenin and glucoerysolin, were synthesized exclusively in addition line g. Addition line i produced sinigrin, not detectable in both parents. The variations in GSL content are not correlated with resistance against beet cyst nematode (Heterodera schachtii Schmidt).   &nbsp

Biotechnological tools for improvement of black nightshade (Solanum nigrum L. complex), valuable medicinal and vegetable plants in Kenya

Solanum nigrum complex is a group of plant species used as indigenous vegetables but also as traditional medicinal plants in Kenya and other parts of the world. In Kenya, just like in most African countries, both the unripe fruits and leaves are used to cure different ailments. This vegetable is said to improve the CD4 count in HIV patients and all HIV patients are encouraged to take it as part of their diet. Despite that high value, African nightshade is a neglected crop. Up to now the farmers exploit traditional landraces and accessions. For development of improved African S. nigrum varieties, knowledge is necessary about the genetic structure of the local African nightshade accessions. Amplified fragment length polymorphism (AFLP) technique was performed to discriminate accessions from the Western region of Kenya. Production of haploid plants of the S. nigrum complex and subsequent chromsome doubling is a promising tool to obtain pure inbred lines in a short time. Therefore, in this study, anthers of S. nigrum were cultivated in vitro. It was observed that the microspores underwent the first divisions and calluses were formed

Spontaneous polyploidisation of interspecific and intersectional Pelargonium hybrids during embryo rescue

Modern Pelargonium crispum hybrids (section Pelargonium) show low genetic and phenotypic variation due to the domestication effect. Species of the sections Cortusina, Ligularia, and Pelargonium are potential breeding partners at the diploid level (2n = 2x = 22). Five P. × crispum cultivars were used as seed parents and pollinated with one genotype of P. grandiflorum (section Pelargonium) and three genotypes of P. fulgidum (section Ligularia). In both combinations, embryo rescue was necessary. Embryos were rescued and cultured on Murashige & Skoog medium supplemented with phytohormones. After callus and adventitious shoot regeneration 15 viable interspecific hybrids were obtained from crossbreeding with P. grandiflorum and 11 intersectional hybrids from crossings with P. fulgidum, respectively. The hybrids were cultivated in the greenhouse until flowering. Their hybrid character was evident due to the intermediate morphological traits. Molecular investigations using dp-RAPD analysis confirmed this. Within the F1 population P. × crispum with P. grandiflorum three hybrids and after crossing with P. fulgidum one hybrid possessed larger flowers and fully developed anthers, respectively. Their ploidy level was confirmed as tetraploid using flow cytometry. Therefore, a spontaneous polyploidisation occurred during in vitro regeneration. The tetraploid F1 hybrids are fertile and could be used for further breeding

Mapping of the Rpv Resistance Gene against Downy Mildew in Pea (Pisum sativum L.)

Die Entwicklung von Sorten, welche eine Resistenz gegen den Erreger des Falschen Mehltaus (Peronospora viciae f. sp. pisi) aufweisen, hat für Erbsenzüchter einen hohen Stellenwert, da dieser Pilz deutliche Ertragsminderungen und Qualitätseinbußen verursachen kann. In der vorliegenden Arbeit wurde eine spaltende Nachkommenschaft von 335 F2-Nachkommen einer Initialkreuzung zwischen der anfälligen Hochleistunssorte `Topaz´ und der resistenten Zuchtlinie `Gen. 27´ erstellt. Jeweils 10 F3-Nachkommen dieser 335 F2-Pflanzen wurden in der Klimakammer auf Resistenz gegen den Falschen Mehltau getestet um auf den Genotyp der ursprünglichen F2-Pflanze schließen zu können. Das Verhältnis von 94 homozygot resistenten, 161 heterozygot resistenten und 80 homozygot anfälligen F2-Pflanzen weicht nicht signifikant von einer 1:2:1-Spaltung ab, die für das Vorliegen eines dominanten Resistenzgens erwartet wird. Das Resis­tenzgen Rpv wurde auf Kopplungsgruppe 1 der Erbse kartiert. Diese Kopplungsgruppe wurde anschließend mit weiteren molekularen Markern, die in der Literatur beschrieben wurden, gesättigt. Der Marker AD147 wurde dabei als proximaler Marker mit der geringsten Distanz (4,4 cM) bestimmt, während in distaler Position AB28 eine Distanz von 18,8 cM aufwies. Durch Nutzung der Synthenie zum Medicago truncatula Chromosom 5 konnten keine enger gekoppelten Marker ermittelt werden. Der Nutzen der identifizierten Marker in unabhängigem Zuchtmaterial konnte jedoch demonstriert und auch die Basis für eine zukünftige Feinkartierung des Resis­tenzgens gelegt werden.Downy mildew causes severe yield and quality losses in pea (Pisum sativum L.). Therefore, the development of downy mildew resistant varieties is of high priority for pea breeders. Within this study in total 335 F3 families from a cross of the highly susceptible green pea variety `Topaz´ with the resistant breeding line `Gen. 27´ were tested for resistance behaviour against Peronospora viciae f. sp. pisi to determine the genotype of the corresponding F2 parental plants. The ratio 94:161:80 for homozygous resistant, heterozygous resistant and homozygous susceptible F2 plants was not significantly different from 1:2:1, expected for the effect of a single dominant resistance gene. The resistance gene Rpv was mapped to linkage group 1 of the pea genetic map. This linkage group was saturated by molecular markers available from lite­rature. The marker AD147 was identified as nearest proxi­mal flanking marker with 4.4 cM distance, and in distal position marker AB28 with 18.8 cM distance. Further marker saturation using the syntenic relationship of P. sativum and Medicago truncatula was not effective. The usefulness of the identified markers for marker assisted selection has been confirmed in independent pea breeding material and the results of this study should lay the basis for future fine mapping studies

Enhanced expression of radish-specific proteins in a disomic rapeseed-radish chromosome addition line resistant to root-knot nematodes

Wurzelgallennematoden sind weltweit für ganz erheb­liche Ertrags- und Qualitätseinbußen verantwortlich. Für den tropischen und subtropischen Teil Chinas sind ins­besondere Meloidogyne incognita und M. javanica von Bedeu­tung. Die disome Additionslinie ee einer kompletten Serie von Raps-Rettich-Additionslinien hatte sich in vorherigen Versuchen als resistent gegenüber diesen beiden Nematodenarten erwiesen. Das Proteinmuster dieser disomen Additionslinie wurde mittels zweidimensionaler Gelelektrophorese und Image Master 5.0 Software mit dem des Rettich-Donors und dem des Raps-Rezipienten verglichen. Differentiell exprimierte Proteine wurden mittels MALDI-TOF-TOF/MS identifiziert. Drei Rettich-spezifische Proteine, die eine erhöhte Expression in der Additionslinie ee aufwiesen, sollen in einem zweiten Schritt auf eine potentielle Funktion im Resistenzmechanismus untersucht werden.Root-knot nematodes cause significant economic losses worldwide each year. Species with especially high relevance in the tropical and subtropical part of China are Meloidogyne incognita and M. javanica. The disomic rapeseed-radish chromosome addition line ee was shown in former experiments to be highly resistant against these southern root-knot nematodes. In this study, differen­tially expressed proteins in the roots of the addition line ee, its radish donor line and its rapeseed recipient line cv. Madora were screened by two-dimensional gel electrophoresis and Image Master 5.0 software. These proteins were identified by MALDI-TOF-TOF/MS. Three radish-specific proteins with an increased expression in rapeseed-radish addition line ee will be further analyzed for their potential role in nematode resistance

Characterisation of Alternaria radicina isolates and assessment of resistance in carrot (Daucus carota L.)

Alternaria radicina ist der Erreger der weltweit auftretenden Schwarzfäule an der Möhrenwurzel. Von Möhren- (Daucus carota) bzw. Petersilienblättern (Petroselinum crispum) wurden vier Alternaria spp. Isolate gewonnen und in Relation zu den Alternaria Arten A. radicina, A. carotiin­cultae und A. petroselini der Alternaria Sektion Radicina, charakterisiert und differenziert. Untersucht wurden Koloniewachstumskriterien, morphologische Merkmale und die Intensität der Sporulation. Typisch für A. radicina Isolate ist die Bildung gelber Pigmente auf angesäuer­tem Kartoffeldextroseagar (APDA). Die Pathogenität der Alternaria Isolate wurde durch Bioassays von Blattsegmenten eines Differenzial-Wirtspflanzensortiments bestehend aus vier Arten aus der Familie Apiaceae untersucht. Verschiedene Möhrensorten und eine Wildform wurden genutzt, um die Aggressivität der Pathogene zu charakterisieren. Die Krankheitssymptome wurden durch digitale Bildanalyse (Digital image analysis system, DIAS, LemnaTec, Deutschland) quantifiziert. Weiterhin konnte mit Hilfe des DAS-ELISA die Erregervermehrung im gesamten pflanzlichen Gewebe erfasst werden. Drei Isolate konnten als A. radicina identifiziert werden und eins als A. petroselini. Zwei A. radicina Isolate unterschiedlicher Aggressivität wurden genutzt, um die Resistenz eines 14 Genotypen umfassenden Möhrensortiments zu bewerten.Alternaria radicina is a fungal pathogen that causes the black rot disease of carrot. Four Alternaria spp. isolates associated with black rot symptoms collected from carrot (Daucus carota) and parsley (Petroselinum crispum) were characterised and differentiated in relation to the closely related Alternaria species A. radicina, A. carotiincultae and A. petroselini belonging to the Alternaria sect. Radi­cina. The Alternaria isolates were differentiated for their growth rates and colony margins. A typical feature of A. radicina isolates is the production of high amounts of yellow pigments on acidified potato dextrose agar (APDA). Furthermore, sporulation intensity and conidia morphology were determined to classify the potential new A. radi­cina isolates. The pathogenicity of the Alternaria isolates was determined by bioassays with detached leaves of four Apiaceae species. Different carrot cultivars and one wild relative were used to estimate aggressiveness of the isolates. The disease symptoms were quantified in bio­assays using a digital image analysis system (LemnaTec). Additionally, a DAS-ELISA with polyclonal antibodies was used to detect the development of fungal pathogens. As result of the morphological and molecular characteris­tics as well as the pathogenicity assay, three isolates were verified as A. radicina and one as A. petroselini. Finally, two isolates with different aggressiveness were used to screen a set of 14 carrot genotypes for resistance to A. radi­cina

Mapping genes governing flower architecture and pollen development in a double mutant population of carrot

A linkage map of carrot (Daucus carota L.) was developed in order to study reproductive traits. The F2 mapping population derived from an initial cross between a yellow leaf (yel) chlorophyll mutant and a compressed lamina (cola) mutant with unique flower defects of the sporophytic parts of male and female organs. The genetic map has a total length of 781 cM and included 285 loci. The length of the nine linkage groups ranged between 65 cM and 145 cM. All linkage groups have been anchored to the reference map. The objective of this study was the generation of a well-saturated linkage map of D. carota. Mapping of the cola-locus associated with flower development and fertility was successfully demonstrated. Two MADS-box genes (DcMADS3, DcMADS5) with prominent roles in flowering and reproduction as well as three additional genes (DcAOX2a, DcAOX2b, DcCHS2) with further importance for male reproduction were assigned to different loci that did not co-segregate with the cola-locus

Studies on the Identification of Resistance to Fusarium oxysporum (Schlecht.) in Different Genetic Backgrounds of Asparagus officinalis (L.) and Its Defense Responses

Due to the restricted genetic diversity among current asparagus cultivars, wild relatives are of particular interest as a source of resistance. In this study, seventeen cultivars and wild relatives were tested for their resistance to Fusarium oxysporum in the seedling test. Two isolates differing in virulence (single spore lines with high and low virulence) were used for testing. Most of the tested genotypes showed high infestation, whereby Asparagus aethiopicus caused no browning of the roots or growth depression. This wild relative was evaluated for its defence response after infection with F. oxysporum. For comparison, the wild relative Asparagus densiflorus and Asparagus officinalis cv. Thielim were tested. Like A. densiflorus, A. aethiopicus showed accumulation of hydrogen peroxide as a defence mechanism, while Asparagus officinalis cv. Thielim showed no storage of hydrogen compounds