A Detection Method for Tropical Race 4 of the Banana Pathogen Fusarium oxysporum f. sp. cubense

Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of Fusarium wilt, the devastating disease that ruined the ‘Gros Michel’ (AAA)-based banana production in the first half of the 20th century. The occurrence of a new variant in Southeast Asia that overcomes the resistance in Cavendish clones such as ‘Grand Naine’ (AAA) is a major concern to current banana production worldwide. The threat posed by this new variant, called tropical race 4 (TR4), may be overcome by the introduction of resistant cultivars. However, the identification of new resistant sources or breeding for resistance is a long-term effort. Currently, the only option to control the disease is to avoid or reduce the spread of the pathogen by eradication of infected plants and isolation of infested plantations. This requires sensitive and highly specific diagnostics that enable early detection of the pathogen. A two-locus database of DNA sequences, from over 800 different isolates from multiple formae speciales of F. oxysporum, was used to develop a molecular diagnostic tool that specifically detects isolates from the vegetative compatibility group (VCG) 01213, which encompasses the Foc TR4 genotype. This diagnostic tool was able to detect all Foc TR4 isolates tested, while none of the Foc isolates from 19 VCGs other than 01213 showed any reaction. In addition, the developed diagnostic tool was able to detect Foc TR4 when using DNA samples from different tissues of ‘Grand Naine’ plants inoculated with TR4 isolate

Pathogenic and Molecular Characterization of Fusarium oxysporum f.sp. ciceri Causing Chickpea Wilt through ISSR Markers

In the present investigation the pathogenic and genetic variability was assayed, amongst the seven isolates of Fusarium oxysporum f.sp. ciceri (Foc) collected from different agro-climatic zones of Maharashtra State, India. The isolates of Fusarium oxysporum f.sp.ciceri were confirmed by SCAR marker which yielded 1.5 KD band. The pathogenicity of each isolate was confirmed using the wilt susceptible chickpea genotype JG-62. On the basis of pathogenic ability the isolates were grouped as highly pathogenic (FOC-2, FOC-5, FOC-6), strongly pathogenic (FOC-1,FOC-3) and moderately pathogenic (FOC-4,FOC-7). Eight Inter Simple Sequence Repeats primers (ISSRs) were used to determine the genetic variability in seven isolates Fusarium oxysporum f.sp. ciceri. The seven primers produced 80 scorable bands. Off 80 bands, 73 bands were polymorphic and average level of polymorphism was 91.25 per cent. In UPGMA analysis, Foc-1 (Wardha) was found to have higher value of similarity coefficient (0.8375) whereas Foc-2 (Lonar) was found to have lower value of similarity coefficient (0.4625). The isolates of Fusarium oxysporum f.sp.ciceri were grouped into two major clusters. First group, cluster-A includes isolates belonging to Wardha, Washim and Lonar. Second group, cluster-B includes Nashik, Ahmednagar, Rahuri and Pune. It shows that Foc-1 (Wardha) have higher value of similarity coefficient with Foc-3 (Washim) whereas Foc-2 (Lonar) have lower value of similarity coefficient with Foc-5 (Ahmednagar).The similarity matrix indicated that seven isolates of Fusarium oxysporum f.sp.ciceri exhibited in between 46-84 per cent similarity coefficient

Potensi Cendawan Endofit Dalam Mengendalikan Fusarium Oxysporum F.sp. Cubense Dan Nematoda Radopholus Similis Cobb. Pada Tanaman Pisang Barangan (Musa Paradisiaca L.) Di Rumah Kaca

Potential of endophytic fungal to control Fusarium oxysporum f.sp. cubense (Foc) andnematode Radopholus similis (Rs) on banana cv. Barangan (Musa paradisiaca L.) crop ongreenhouse. This research aims to intens and find potential endophytic as biocontrol agents tocontrol Foc and Rs on banana cv. Barangan crop. This research used Completely RandomizedDesign (CRD) non factorial consist thrithteen treatments and three replications. Replications;control (without inoculated), inoculated 300 Rs, inoculated Foc, inoculated 300 Rs one week laterinoculated Foc two weeks later inoculated endophytic 5BSBH's isolate, inoculated 300 Rs oneweek later inoculated Foc two weeks later inoculated endophytic 4BSU's isolate, inoculated 300 Rsone week later inoculated Foc two weeks later inoculated endophytic 1BJH's isolate, inoculated 300Rs one week later inoculated Foc two weeks later inoculated endophytic 1BTAH's isolate,inoculated 300 Rs one week later inoculated Foc two weeks later inoculated endophytic 1BSHT'sisolate, inoculated endophytic 5BSBH's isolate one week later inoculated 300 Rs two weeks laterinoculated Foc, inoculated endophytic 4BSU's isolate one week later inoculated 300 Rs two weekslater inoculated Foc, inoculated endophytic 1BJH's isolate one week later inoculated 300 Rs twoweeks later inoculated Foc, inoculated endophytic 5BSBH's isolate one week later inoculated 300Rs two weeks later inoculated Foc, inoculated endophytic 1BSHT's isolate one week laterinoculated 300 Rs two weeks later inoculated Foc. The results showed that endophytic fungal hadthe potency as biocontrol agent in controlling Fusarium wilt of banana cv. Barangan

First-Order Query Evaluation with Cardinality Conditions

We study an extension of first-order logic that allows to express cardinality conditions in a similar way as SQL's COUNT operator. The corresponding logic FOC(P) was introduced by Kuske and Schweikardt (LICS'17), who showed that query evaluation for this logic is fixed-parameter tractable on classes of structures (or databases) of bounded degree. In the present paper, we first show that the fixed-parameter tractability of FOC(P) cannot even be generalised to very simple classes of structures of unbounded degree such as unranked trees or strings with a linear order relation. Then we identify a fragment FOC1(P) of FOC(P) which is still sufficiently strong to express standard applications of SQL's COUNT operator. Our main result shows that query evaluation for FOC1(P) is fixed-parameter tractable with almost linear running time on nowhere dense classes of structures. As a corollary, we also obtain a fixed-parameter tractable algorithm for counting the number of tuples satisfying a query over nowhere dense classes of structures

Reaction of banana cultivars to the Meloidogyne javanica X Fusarium oxysporum f. sp. cubense complex.

The interaction Fusarium oxysporum f. sp. cubense (Foc) x nematode and the genetic variability of Foc are the main problems with potential to affect the use of resistant varieties in the management of the Panama disease. The objective of this work was to evaluate the interaction between Foc and Meloidogyne javanica on the banana of the Prata Anã, Grande Naine and BRS Princesa cultivars. The experiment was conducted in a randomized block design, with six treatments and ten replications, which differed in the inoculation time of each pathogen. Simultaneous inoculation with Foc and M. javanica, inoculation with Foc one week before inoculation with M. javanica, and inoculation with M. javanica one week before inoculation with Foc. In addition to the controls, Foc isolated, M. javanica isolated, and cultivars without the pathogens. The seedlings were transplanted in 3-liter pots with sterile soil infested with 40 grams of Foc inoculum at the concentration of 1x106CFU/gram and 1000 eggs and J2 of M. javanica. At the end of 56 days, the treatments with 'Grande Naine' presented the highest reproduction factors of M. javanica. In the 'Prata Anã' no interaction was observed between Foc x M. javanica. The treatments with simultaneous inoculation of the two pathogens, and with Foc a week before, in the 'BRS Princesa', presented the highest external disease indices (DI), which promoted the highest AUDPC. The highest internal DI were observed in the treatments Foc+Mj+Grande Naine, Foc+Mj+BRS Princesa, Mj+Grande Naine+Foc and Foc+BRS Princesa+Mj. The simultaneous presence of M. javanica and Foc increases the severity of the Panama disease in Grande Naine and BRS Princesa cultivars