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The identification of effectors from pathogenic microbes is one of the most important subjects for elucidating infection mechanisms. Wheat blue dwarf (WBD) phytoplasma causes dwarfism, witches' broom, and yellow leaf tips in wheat plants, resulting in severe yield loss in northwestern China. In this study, 37 candidate effector proteins were transiently expressed in Nicotiana benthamiana. Plants expressing the SAP11-like protein SWP1 exhibited typical witches' broom. Interestingly, another protein, SWP11, induced both cell death and defence responses, including H 2 O 2 accumulation and callose deposition. Analysis by qRT-PCR was used to show that a marker gene of the hypersensitive response, HIN1, and three pathogenesis-related genes, PR1, PR2 and PR3, were significantly up-regulated in leaves of N. benthamiana expressing SWP11. In addition, SWP12 and SWP21 (TENGU-like) were shown to suppress SWP11-, BAX-, and/or INF1-induced cell death. These results indicated that SWP21 has a distinct role in virulence compared with TENGU and that WBD phytoplasma possesses effectors that target plant proliferation and defence responses. The ability of these effectors to trigger or suppress plant immunity provides new insights into the phytoplasma-plant interaction.

Aims: Wheat (Triticum aestivum) is one of the most important crop species, but yields are often drastically reduced by rust epidemics. In this report, we describe a rapid and sensitive immunofluorescence method for the detection of urediniospores of the fungi Puccinia striiformis f. sp. tritici, Puccinia triticina and Puccinia graminis f. sp. tritici, which are causal agents of wheat rust. Methods and Results:The method uses monoclonal antibody LPT-2 against the urediniospores of P. triticina and PE-cy3 goat anti-mouse. Urediniospores of P. triticina or those of two species that are difficult to distinguish from P. triticina, P. striiformis f. sp. tritici or P. graminis f. sp. tritici were immobilized on a glass slide, and the sample was then treated with LPT-2. Thereafter, a second antibody, goat anti-mouse conjugated PE-cy3, was added, and the slide was observed in a fluoroscope. The fluorescent signal was strong with P. triticina urediniospores, weak with P. striiformis f. sp. tritici urediniospores and weakto-intermediate with P. graminis f. sp. tritici urediniospores. The detection limit of this method was 2 ng ml À1 of the monoclonal antibody LPT-2. Conclusions:In this article, we describe the production and diagnostic application of a novel mouse monoclonal antibody specific to urediniospores of P. triticina. Significance and Impact of the Study: After further technical development, this method may become a tool for on-site identification of P. triticina urediniospores and will therefore help in the selection and timing of fungicide applications for control of wheat rust outbreaks.

A total of 129 wheat cultivars collected from local breeders in four ecological regions in China was evaluated for Fusarium head blight resistance after natural infection under epidemic conditions. The disease index was scored and seven toxins concentrations were determined by UPLC-MS/MS. The disease index ranged from 6.3 to 80.9% and a strong correlation was found between the regions from which the cultivars originate and disease index. The middle and lower reaches of Yangtze River Region showed the highest disease resistance, followed by the upper reaches of the Yangtze River Region. FHB resistance of cultivars from northern and southern Huanghuai Region was lowest and all cultivars in these regions are highly or moderately susceptible. Disease index was significantly correlated with toxin accumulation on nation scale, but no clear correlation was found within most ecological regions. The toxin accumulation was also not well correlated with resistant levels. As the incidence of FHB has increased dramatically over the last decade, improved FHB resistance in cultivars is urgently needed. We recommend that besides scoring for disease index also mycotoxin accumulation in cultivars is incorporated in breeding procedures and the evaluation of cultivars.

CS-B14Sh and CS-B22Sh are cotton interspecific chromosome substitution (CS)-B lines, in which a pair of short arms of chromosome 14 and chromosome 22 were introgressed from Gossypium barbadense doubled-haploid line 3-79 with the background of Gossypium hirsutum line TM-1, respectively. These two CS-B lines were crossed with TM-1, and segregating progenies (F 2 and F 2:3 , respectively) were obtained. Phenotypic data of lint yield, yield-related traits and fibre-quality traits were collected from two trials. In the cross CS-B14SH X TM-1, QTL for boll weight (BW), lint percentage (LP), fibre upper half mean length (UHML), micronaire reading (MIC), and fibre breaking tensile strength (STR) were repeatedly detected. Alleles from 3-79 decreased BW and MIC, but increased UHML and STR. In the cross CS-B22Sh X TM-1, QTL for BW, LP, UHML, MIC, STR, fibre elongation (EL),seed weight(SW), node of first fruiting branch (NFB) and fibre uniformity index (UI) were repeatedly detected, and alleles from 3-79 decreased UHML, UI and STR, but increased NFB, SW, MIC and EL. QTL clusters were found in both populations.

This method could be used for the on-site identification of T. controversa teliospores in the near future and will help in selecting fungicides to control dwarf bunt of wheat as further technical developments are achieved.

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