Orobanche Research Articles

Генетический анализ устойчивости к расе G Orobanche cumana Wallr. в F2 и ВС1 линий подсолнечника RGP1, RGP2, RGВ, RGL1, RGL2

Генетический анализ устойчивости к расе G Orobanche cumana Wallr. в F2 и ВС1 линий подсолнечника RGP1, RGP2, RGВ, RGL1, RGL2

Genetic Resources of the Sunflower Crop Wild Relatives for Resistance to Sunflower Broomrape

Abstract One of the most threatening holoparasitic plant species is Orobanche cumana Wallr. (sunflower broomrape), mainly distributed in the Mediterranean region and Western Asia where it exclusively parasitizes sunflowers. Sunflower broomrape (BR) is a very destructive parasitic weed causing significant yield losses under high infestations that can easily spread and is vulnerable to mutations. Broomrape is highly variable, controlled by vertical single dominant resistance genes leading to the rapid and frequent breakdown of resistance. This subsequently leads to the continuing need for new unique genes from multiple sources for controlling new emerging virulent races. The USDA-ARS, National Plant Germplasm System crop wild relatives (CWR) collection contains 2,519 accessions of 53 species with 14 annual species (1641 accessions) and 39 perennial species (878 accessions). This CWR collection provides a vast genetic resource for new BR resistance genes, especially in Europe and the Middle East. Sunflower CWR evaluations for new resistance genes for BR races have demonstrated that they are a substantial reservoir for existing and new emerging virulent races. Resistance to sunflower broomrape, including immunity, has been reported in seven annual and 32 perennial species. These sources discovered in the sunflower CWR confer resistance to new virulent broomrape races F, G, and H, and others that have not been assigned a race designation. Since several of the resistant CWR sources are annual and have the same chromosome number as cultivated sunflower, broomrape resistance genes can be incorporated into hybrid sunflower through interspecific hybridization. The diverse sources of resistance from the CWR provide breeders with the prospect for durable broomrape control through exploiting genetic resistance for existing and newly emerging races.

Talaromyces trachyspermus a potential biocontrol agent for branched broom rape (Orobanche ramosa)

Broomrape (Orobanche spp.) is a parasitic plant that leads to significant losses in horticultural crops in Iran. To develop a strategy for biocontrol of broomrape fungal isolates were recovered from broomrape plants exhibiting signs of necrosis and wilt. One isolate with a high level of pathogenicity to broom rape was identified following pathogenicity tests. From cultural and DNA sequence this was identified as Talaromyces trachyspermus. Inoculation of the infected soil in pots with T. trachyspermus, caused a significant reduction in the number of tubercles and number and fresh weight of broomrape shoots (P = 0.01). Inoculated parasitic plant shoots also showed rot symptoms in their stalk. No disease symptoms were observed on tomato. T. trachyspermus is a potential antagonist for biocontrol of broomrape.

Broomrape intimidation to rapeseed-mustard production in semi-arid regions

Broomrape intimidation to rapeseed-mustard production in semi-arid regions

Can we breed for durable resistance to broomrapes

The broomrapes ( Orobanche and Phelipanche ) are parasitic plants that have modified biology to feed on other plants, completely losing autotrophic capability. Some broomrape species have adapted to agricultural ecosystems becoming parasitic weeds. The most damaging weedy broomrapes are O. crenata , O. foetida , O. minor , O. cumana , O. cernua and P. ramosa and P. aegyptiaca , which can severely constrain important dicotyledonous crops, mainly in the Mediterranean Basin. This adaptation is an active process, with recent instances of jumps from non-weedy to weedy behavior, such as for O. cumana adapting to infect sunflower little more than a century ago; O. cernua adapting to infect tomato, tobacco and eggplant; and the more recent example of O. foetida adapting to infect faba bean a few decades ago. This also relates to parasite speciation towards particular hosts, such as the ongoing process of P. ramosa populations infecting winter oilseed rape. Sunflower is a unique situation, in which highly effective monogenic resistances to broomrape have been identified and widely deployed by sunflower breeders. This was accompanied by the subsequent appearance and spread of new races of O. cumana overcoming the introduced host resistance genes. In contrast, only quantitative resistances were identified and exploited by breeders in other crops against other broomrapes. Achievements and prospects for broomrape resistance breeding are presented and critically discussed, along with complementary measures needed to preserve durability of resistance. Particularly important is the prevention of human-driven broomrape seed dispersal by crop seed trade, together with broomrape seed soil-bank demise.

INTEGRATED MANAGEMENT OF DISEASES TO RECLAIM GRAIN LEGUME IN MEDITERRANEAN REGION

Legumes are among the most important crops worldwide just behind cereals for both animal and human consump- tions, being particularly important in Mediterranean agriculture. However, legume acreage in the area is continuously decreasing, whereas it increases in other continents. Yield instability due to diseases is one of the reasons for this decline. Legumes are damaged by a number of diseases and available management methods are scarce or uneconomical. This includes aerial fungi, together with soilborne pathogens associated with foot and root rot complexes, nematodes, parasitic weeds bacteria and viruses. The use of genetic resistance is the most economical and environmentally friendly control method. However, no efficient sources of resistance have been described to some diseases, or it is scarce and of complex nature, making necessary the implementation of other control measures. Phenotypic expression of resistance is usually poorly described. Comprehensive studies on host status and virulence of the causal agents are often missing, and in many instances there is little understanding on the existence of races and their distribution. Also, available information on levels of resistance and on the responsible mechanisms is often incomplete. This is a major limitation for any breeding programme. Only after significant input to improve existing knowledge on biology of the causal agents as well as on the plant, resistance breeding will be efficiently accelerated. In this contribution relative importance of a number of diseases on legume crops and available management strategies will be critically presented, with a special focus on Mediterranean context. For this, examples will be given on faba bean, pea and chickpea crops and associated rusts, ascochytas, powdery mildews, wilts and broomrape problems.

GENETIC ANALYSIS OF RESISTANCE TO OROBANCHE CRENATA (FORSK.) IN A PEA (PISUM SATIVUM L.) LOW-STRIGOLACTONE LINE

Crenate broomrape ( Orobanche crenata Forsk.) is a root parasitic weed severely threatening the cultivation of pea ( Pisum sativum L.) in Mediterranean agricultural settings. We recently characterized a pea line highly resistant to O . crenata , named ROR12. Analysis of root exudates indi- cated that ROR12 resistance is possibly due to lower exu- dation of strigolactones, carotenoid-derived compounds acting in the rhyzosphere as broomrape germination stim- ulants. Here, we provide a first genetic characterization of ROR12 resistance. Two segregating F 2 populations origi- nating from the cross between ROR12 and two susceptible commercial pea cultivars were assayed for response to O . crenata , together with the respective parental lines and F 1 generations. Susceptibility of F 1 individuals indicated that resistance is recessively inherited. In F 2, significant devia- tion from Gaussian distribution suggested that broomrape resistance is not a quantitative trait, as it was previously hypothesized, but is rather controlled by one or a few ma- jor loci. Molecular analysis with RAPD and SSR markers identified a genomic region on pea linkage group 3 associ- ated with the resistant phenotype. Finally, transcriptional evidence was provided, supporting the hypothesis that ROR12 resistance is due to reduced strigolactone biosyn- thesis. Overall, this study provides insights on the control of broomrape resistance and lays the foundation for future work addressing the fine-mapping and cloning of genes controlling strigolactone biosynthesis and/or broomrape resistance.

Effect of parasitism severity by sunflower broomrape on yield formation and physiological characteristics of sunflower

Effect of parasitism severity by sunflower broomrape on yield formation and physiological characteristics of sunflower

Biochemical analysis of induced resistance in chickpea against broomrape (Orobanche foetida) by rhizobia inoculation.

This study examined the capacity of Rhizobium sp. strain PchAZM to reduce parasitism of chickpea by Orobanche foetida under greenhouse conditions, and assessed the relative impact of rhizobia on the expression of chickpea defense response against broomrape. Growth chamber experiments using Petri dishes revealed that rhizobia infection on chickpea roots reduced broomrape seed germination, and restricted the broomrape attachment to host roots while retarding tubercle formation and development by the parasite. In pot experiments, chickpea roots inoculated with rhizobia reduced the total number of broomrape by up to 90%. Broomrape necrosis was observed both before and after parasite attachment to inoculated chickpea roots in Petri dishes and pot experiments. Reduction in infection was accompanied by enhanced levels of the defence-related enzymes phenylalanine ammonia lyase (PAL) and peroxidase (POX). Increased levels of phenolics were recorded in the roots of rhizobia-inoculated plants grown in the presence of broomrape. The results suggest that rhizobia could be used for protection of chickpea against O. foetida .

Physiological races identification of sunflower broomrape in 4 provinces of China

Physiological races identification of sunflower broomrape in 4 provinces of China

First Report of Orobanche nana on Celery in Italy

First Report of <i>Orobanche nana</i> on Celery in Italy

Effects of Nitrogen Fertilizers on Growth of Egyptian Broom Rape (Orobanche aegyptiaca) in the Presence of the Host of Sunflower (Helianthus annus) in Pot Conditions

Effects of Nitrogen Fertilizers on Growth of Egyptian Broom Rape (Orobanche aegyptiaca) in the Presence of the Host of Sunflower (Helianthus annus) in Pot Conditions

The effect of duration of solarization on controlling branched broomrape ( Phelipanche ramosa L.) and some weed species

In this study, the effects of two-, four- and six-week periods of solarization on Phelipanche ramosa and other weeds were determined in tomato greenhouses between 2007-2009 in Aydin Province/Turkey. In the first year, the maximum temperatures recorded in the soil in the solarized area were 54 °C at a depth of 5 cm, 47 °C at 10 cm and 41 °C at 20 cm. In the second year, the maximum temperatures in the solarized area were 44.5 °C at 5 cm, 39.7 °C at 10 cm and 34.7 °C at 20 cm. In the first season, regardless of solarization time, solarization reduced the density of Amaranthus viridis , Setaria verticillata, Urtica urens, Solanum nigrum, Portulaca oleracea , Chenopodium album and Stellaria media by 99-100 %. Solarization’s effect on P. ramosa was 100 % regardless of the duration of solarization. In the second year, 2-, 4- and 6-week solarization periods, respectively, reduced A. viridis by 67, 73 and 93 %; S. verticillata by 78, 80 and 94 %; U. urens by 99, 100 and 100 %; and S. media by 100 % for all treatments. When P. ramosa was examined, a 2-week solarization period was found to result in a 20 % decrease and a 4-week solarization period resulted in a 47 % decrease. Six weeks of solarization reduced P. ramosa by 74 %. Additionally, there was an increase in tomato yield in response to longer periods of solarization. Keywords: Broomrape, solarization, weed control Der Effekt der Solarisationsdauer auf astigen Sommerwurz ( Phelipanche ramosa L. ) und einige andere Unkrautarten Bei den Versuchen zwischen 2007 und 2009 in Aydin, Turkei wurde die Wirkung von zwei, vier- und sechswochiger Bodensolarisation auf eine parasitierende Unkrautart Phelipanche ramosa und andere Unkrautarten untersucht. Im ersten Versuchsjahr waren die maximalen Bodentemperaturen bei 5, 10 und 20 cm Bodentiefe 54, 47 bzw. 41 °C. Im zweiten Versuchsjahr wurden niedrigere Temperaturen erreicht, so dass bei 5,10 und 20 cm Bodentiefe die maximalen Temperaturen 44,5, 39,7 bzw. 34,7 °C betrugen. Ergebnisse zeigten, dass beim ersten Versuch P. ramosa bei allen Bodensolarisationsdauer zu 100 % kontrolliert wurde. Ebenfalls wurden andere Arten wie Amaranthus viridis, Setaria verticillata, Urtica urens , Solanum nigrum, Portulaca oleracea, Chenopodium album und Stellaria media bei 99-100 % kontrolliert. Beim zweiten Versuch war die Wirkung der Solarisation abhangig von der Dauer. Beim A. viridis erzielte 2-, 4- und 6-wochige Solarisation eine Wirkung von 67, 73 bzw. 93 %. S. verticillata Bekampfung war 70, 80 und 94 % bei 2-,4- und 6-wochige Solarisation. U. urens und S. media Bekampfung lag bei 99-100 % unabhangig von der Solarisationsdauer. Bei P. ramosa 2-, 4 und 6-wochige Solarisation erzielten 20, 47 und 74 % Wirkung. Der Tomatenertrag war hoher mit verlangerter Solarisationsdauer. Stichworter: Solarisation, Sommerwurz, Unkrautbekampfung

Bioprotection mechanisms of pea plant by Rhizobium leguminosarum against Orobanche crenata

Broomrapes are achlorophyl holoparasites of many important economic dicotyledonous crops. As weeds, they significantly decrease crop yields. Orobanche crenata is an important constraint to Mediterranean area pea (Pisum sativum L.) cultivation, as no resistant variety is available. Our previous researches showed that several Rhizobium leguminosarum strains decrease damages caused by O. crenata in pea. The aim of this work was to characterize the resistance induced by R. leguminosarum against broomrape. Higher concentrations of phenolic compounds and lignin were observed in pea roots inoculated with Rhizobia, in comparison to non inoculated. Polyphenol oxidase and peroxidase activities were significantly higher in inoculated plants as compared to non-inoculated ones. These results suggest that the mechanisms of induced resistance by Rhizobia against O. crenata involve an elevated induction of the phenylpropanoid pathway, conferring mechanical and chemical barriers confronting the invading parasite. Key words: Broomrape, rhizobium, biocontrol, defense related enzymes, PPO, POX, phenols, lignin. .

Improved mycoherbicidal activity of Fusarium arthrosporioides

-1 ) Orobanche tubercles mortality increased to 37 and 78%. Cellulase treatment alone was ineffective. Only a hypersensitive reaction (9% death) resulted in the absence of cellulase. The findings add to the commercial value of F. arthrosporioides as a potential mycoherbicide when sufficiently virulent.

Biological control of Egyptian broomrape (Orobanche aegyptiaca) using Fusarium spp.

Summary. The broomrape (Orobanche spp.) is an obligate holoparasitic weed that causes severe damage to many important vegetable crops. Many broomrape control strategies have been tested over the years. In this investigation, 125 Fusarium spp. isolates were recovered from diseased broomrape spikes collected from fields in agricultural areas near Hebron. The pathogenicity of isolates on broomrape was evaluated using an inoculum suspension containing mycelia and conidia. The most effective Fusarium isolates significantly increased the dead spikes of broomrape by 33.6–72.7% compared to the control; there was no obvious pathogenic effect on the tomato plants. Fusarium spp. isolates Fu 20, 25 and 119 were identified as F. solani, while Fu 30, 52, 59, 87 and 12-04 were F. oxysporum. In addition, the two previously known Fusarium strains, F. oxysporum strain EId (CNCM-I-1622) (Foxy) and F. arthrosporioides strain E4a (CNCM-I-1621) (Farth) were equally effective in controlling broomrape parasitizing tomato plants grown in pots, where the dead spikes of broomrape increased by 50.0 and 51.6%, respectively .

Fusarium Rot of Orobanche ramosa Parasitizing Tobacco in Southern Italy

In tobacco crops grown in the province of Caserta (southern Italy), we noted, for the first time in Italy, very many broomrape (Orobanche ramosa) plants exhibiting mycosis caused by a strain of Fusarium oxysporum that is not pathogenic to tobacco. After a brief description of the symptoms of the disease and its incidence in the field, we discuss, on the basis of the observations made and the data supplied by the literature, the feasibility of using this fungus in programmes to control Orobanche.

Assessment of Sensitivity to Frost in Ochrus chickling (Lathyrus ochrus (L.) D.C.) by Chlorophyll Fluorescence Analyses

AbstractOchrus chickling (Lathyrus ochrus (L.) D.C.) is a promising feed legume for rain‐fed farming systems in the Mediterranean environments of West Asia and North Africa (WANA) because of its drought tolerance and resistance to broom rape (Orobanche crenata Forsk.). However, it is highly susceptible to cold and improving Its resistance would further improve its adaptation.The potential of the chlorophyll fluorescence technique in screening for frost sensitivity in seedlings of five Lathyrus ochrus genotypes and one each of Vicia ervilia (L.) Wild and V. sativa L. was assessed by measuring the rate of rise in induced or variable chlorophyll fluorescence of fully developed leaflets after cold hardening in the open and subsequent exposure to freezing. The method differentiated the highly frost‐susceptible L. ochrus genotypes from the more tolerant Vicia species. Testing the technique with nine genotypes of L. ochrus in which the plants were established, cold‐hardened and frost‐stressed under controlled conditions confirmed its sensitivity even to reveal the narrow inter plant differences that generally exist within a cultivar or genotype to frost. It is therefore considered as a useful screening technique for cold/frost tolerance in L. ochrus.

Cell Selection in Vitro for Developing of Herbicide Tolerance in Tobacco

The objective of the present study was the investigation on the problems of cell selection for obtaining herbicide tolerant variants of important Bulgarian tobacco cultivars from callus cultures. These cultures survived toxic levels of the herbicide Glyphosate, expression of this tolerance in the regenerated plants and their practical application in infected field areas with broom rape (Orobanche ramosa). These investigations showed that the high concentration of Glyphosate (100 mg/l) in the medium can be used as a basis for selection of Glyphosate tolerant callus clones. It was observed regeneration on the selective medium with 40 mg/l Glyphosate from these callus lines tolerant to 100mg/l Glyphosate in the callus induced medium. Seeds from the regenerants spotted with 300 mg/l Glyphosate were tested for Glyphosate sexual transmission.

Solarization; a physical control method for weeds and parasitic plants (Orobanche spp.) in Mediterranean agriculture

Summary. Experiments were conducted between 1985 and 1988 to evaluate the effect of duration and time of solarization on the control of two broom rapes (Orobanche aegyptiaca Pers., O. crenata Forsk.) and other weeds common in the fields of faba bean (Vicia faba L.) and lentil (Lens culinaris Medik.) in West Asia. Solarization was performed by applying clear polyethylene sheet to the soil for 0, 10, 20, or 40 days in 1985/86, 0, 30, or 40 days in 1986/87 and 0, 20, 30, 40 or 50 days in 1987/88 during the hot season (July and August) and for 50 days immediately before sowing during milder weather (September and October) in 1986/87. Best control was obtained with solarization for 30–50 days in the hot season. Maximum soil temperature under polyethylene at 5 cm was 55°C in 1985, 48°C in 1986 and 57°C in 1987. Broomrape dry weight decreased in the first experiment by more than 90% in both faba bean and lentil fields. Solarization controlled broom‐rape and other weeds in the following two seasons when the soil was left undisturbed during the season of the treatment.