We report here the complete genome sequences of two Ralstonia pseu-dosolanacearum strains, isolated from the warm northeast region of Brazil. They display divergent (compatible versus incompatible) interactions with the resistant tomato line Hawaii 7996. Polymorphisms were detected in a subset of effector genes that might be associated with these contrasting phenotypes. R alstonia pseudosolanacearum is a soilborne pathogen and one of the main causal agents of the bacterial wilt (BW) disease of tomato (Solanum lycopersicum L.) and other crops (1). R. pseudosolanacearum is currently classified as a distinct species within the R. solanacearum complex, which comprises strains of phylotypes I and III (2-5). Although they are of putative exotic origin, R. pseudosolanacearum phylotype I isolates are currently disseminated in Brazil (north, northeast, and central regions) and infect mainly Solanaceae crops (tomato, peppers, eggplant, and scarlet eggplant) (6, 7). In this study, two tomato-infecting R. pseudosolanacearum strains from the warm Brazilian northeast region were sequenced in order to analyze candidate genes associated with their divergent (compatible versus incompatible) interactions with the tomato line Hawaii 7996, which is the main breeding source of BW resistance in this vegetable crop (8, 9). Strain RS 476 (sequevar I-18 from Maranhão state) is characterized by its ability to induce severe BW symptoms on Hawaii 7996 (60% incidence), whereas strain CRMRs218 (also sequevar I-18 from Pernambuco state) is able to induce severe BW symptoms in a wide range of tomato cultivars, but it is avirulent to Hawaii 7996.

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. AbstractCapsicum species are commercially grown for pepper production. This crop suffers severely from thrips damage and the identification of natural sources of thrips resistance is essential for the development of resistant cultivars. It is unclear whether resistance to Frankliniella occidentalis as assessed in a specific environment holds under different conditions. Additionally, other thrips species may respond differently to the plant genotypes. Screening for robust and general resistance to thrips encompasses testing different Capsicum accessions under various conditions and with different thrips species. We screened 11 Capsicum accessions (C. annuum and C. chinense) for resistance to F. occidentalis at three different locations in the Netherlands. Next, the same 11 accessions were screened for resistance to Thrips palmi and Scirtothrips dorsalis at two locations in Asia. This resulted in a unique analysis of thrips resistance in Capsicum at five different locations around the world. Finally, all accessions were also screened for resistance to F. occidentalis in the Netherlands using a leaf disc choice assay, allowing direct comparison of whole plant and leaf disc assays. Resistance to F. occidentalis was only partially consistent among the three sites in the Netherlands.The most susceptible accessions were consistently susceptible, but which accession was the most resistant differed among sites. In Asia, one C. chinense accession was particularly resistant to S. dorsalis and T. palmi, but this was not the most resistant accession to F. occidentalis. Overall, resistance to F. occidentalis correlated with S. dorsalis but not with T. palmi resistance in the C. annuum accessions. Damage inflicted on leaf discs reflected damage on the whole plant level. Our study showed that identifying broad spectrum resistance to thrips in Capsicum may prove to be challenging.Breeding programmes should focus on developing cultivars suitable for growing in defined geographic regions with specific thrips species and abiotic conditions.

A quantitative genetic analysis was conducted to determine the inheritance of androgenetic response in hexaploid triticale. One highly-responsive genotype (Do 1 triticale) and three low-responding advanced CIMMYT lines (Rhino, Juanillo 97 and Ira Drira) were used as parents to produce a complete set of reciprocal F1, F2 and backcross generations. Estimates for genetic effects were determined using a generation-mean analysis following the method of Mather and Jinks. Both embryo induction and plant regeneration potential fitted well with the simple three-parameter additive-dominance (AD) model indicating the absence of any significant epistatic effects. Highly significant additive effects were detected for embryo induction, suggesting that breeding and selection can be effective in improving the induction response of triticale. The high [d]/[h] ratio indicates dominance of the alleles causing high embryo induction. The production of regenerant plants from embryos appeared to be a more complex trait because of its high sensitivity to environmental factors.

Bitter gourd (Momordica charantia L.) is a commercially and nutritionally important market vegetable in Asia cultivated mainly by smallholder farmers. Cucurbit powdery mildew (CPM) caused by Podosphaera xanthii (Px) is a nearly ubiquitous and serious fungal disease of bitter gourd. Five bitter gourd breeding lines (THMC 113, THMC 143, THMC 153, THMC 167, and THMC 170) were selected at the World Vegetable Center for resistance to a local isolate of Px in Kamphaeng Saen, Thailand. We evaluated the resistance potential of these five inbred lines against local isolates of Px at 12 locations in five Asian countries. Plants were inoculated with the respective local Px isolate 15 and 30 days after transplanting and additional Px-infected plants of the inoculated control were interplanted throughout each test. Plants were rated 60 days after transplanting for CPM reaction using a 0 (no evidence of infection) to 5 (>75% infection evident on individual leaves) disease severity scale. THMC 153 and THMC 167 were resistant to the local race of Px in all locations, whereas THMC 143 was observed resistant in all test locations except one in China. THMC 113 was resistant in each location except one in India. THMC 170 was susceptible in three locations in India. The multilocation tests revealed four unique Px races on bitter gourd in different Asian countries and sources of resistance for breeding CPM-resistant bitter gourd cultivars. Six strains of Px isolated from other cucurbits (Cucumis and Cucurbita) and representing five melon CPM races were unable to infect the susceptible M. charantia accession THMC 144 and the five resistant breeding lines, indicating pathotype differences between them and an isolate of M. charantia origin typed as race 1 on melon. THMC 143 and THMC 167, which originated from India, exhibited good yield potential in trials conducted in Thailand, Myanmar, Vietnam, and Bangladesh.