Screening recently identified whitefly/spider mite‐resistant wild tomato accessions for resistance to Tuta absoluta

The tomato leaf miner (Tuta absoluta) is a serious pest of tomato (Solanum lycopersicum) in the tropics and subtropics. Previous World Vegetable Center studies identified selected accessions of S. galapagense, S. cheesmaniae and S. pimpinellifolium that were resistant to whitefly (Bemisia tabaci Genn.) and spider mite (Tetranychus urticae Koch). Here, we evaluated these accessions for resistance to T. absoluta based on the number of eggs from choice bioassays, and larval mortality and adults emerged percentages in no‐choice feeding bioassays at WorldVeg Eastern and Southern Africa (WorldVeg) and the International Centre for Insect Physiology and Ecology (icipe). At WorldVeg, S. galapagense VI063177 exhibited high resistance in both choice and no‐choice bioassays. There was strong negative correlation between larval mortality and adults emerged percentages in the no‐choice feeding bioassays. Results from the icipe experiments were consistent with those of the WorldVeg screening, except for S. pimpinellifolium accession VI030462 , which was susceptible at icipe. Tuta absoluta is rapidly spreading and the resistance sources reported here will be valuable in breeding tomato varieties resistant to this insect and others.     

Evaluation of wild tomato accessions (<Emphasis Type="Italic">Solanum</Emphasis> spp.) for resistance to two-spotted spider mite (<Emphasis Type="Italic">Tetranychus urticae</Emphasis> Koch) based on trichome type and acylsugar content

Tomato wild relatives are important sources of resistance to many pests of cultivated tomato [Solanum lycopersicum L. (syn. Lycopersicon esculentum Mill.)]. Eleven wild tomato accessions previously identified at AVRDC—The World Vegetable Center as resistant to Bemisia tabaci were evaluated for resistance to the two-spotted spider mite [Tetranychus urticae (Koch.)] based on egg numbers using the leaf disc and Tanglefoot no-choice bioassays, and damage scores in choice bioassays. Highest resistance based on choice and no-choice bioassays was identified in AVRDC S. galapagense accessions VI057400, VI045262, VI037869 and VI037239, and S. cheesmaniae accession VI037240, all of which are new sources of T. urticae resistance. In addition, S. pimpinellifolium accession VI030462 exhibited resistance only in the no-choice bioassay based on egg numbers. Resistance to T. urticae based on the number of eggs from the no-choice bioassays was positively correlated with density of type IV glandular trichomes and negatively correlated with densities of type V trichomes. All resistant accessions accumulated high levels of total acylsugars, which were positively associated with type IV trichomes. There was a significant negative relationship between acylsugar content and T. urticae egg numbers from the no-choice bioassays. There was high correlation between the results from the leaf disc test and the Tanglefoot no-choice bioassay. These findings support the possible presence of broad-based insect and mite resistance in accessions closely related to cultivated tomato.     

De novo transcriptome assembly and development of EST-SSR markers for Pterocarpus santalinus L. f. (Red sanders), a threatened and endemic tree of India

Genetic Resources and Crop Evolution - The endemic and precious tree&nbsp;Pterocarpus santalinus L. f. (Red sanders) is a drought hardy species for conservation in peninsular India due to its...     

Arcelins from an Indian wild pulse, Lablab purpureus, and insecticidal activity in storage pests

A partially purified protein fraction was isolated from seed flour of the Indian wild bean, Lablab purpureus, by ion exchange and size-exclusion chromatographies. Partially purified L. purpureus proteins had hemagglutination and glycoslyation properties similar to those of lectins or lectin-like proteins from other pulses. Data obtained from two-dimensional gel electrophoresis, MALDI-TOF, and MALDI-TOF/TOF and N-terminal protein sequencing of the isolated polypeptides from L. purpureus demonstrated that the extract contained proteins similar to isoforms of arcelins 3 and 4 and pathogenesis-related protein 1 (PvPR1) of Phaseolus vulgaris. L. purpureus proteins were resistant to degradation by the commercial enzymes trypsin and chymotrypsin and were moderately resistant to pepsin, but were readily hydrolyzed to smaller peptides by papain. Insect feeding bioassays of the extract with the storage pests Rhyzopertha dominica and Oryzaephilus surinamensis, internal and external feeders of grain, respectively, demonstrated that L. purpureus proteins at 2% in the diet resulted in retarded development. However, a 5% dose of the L. purpureus fraction resulted in complete mortality of all larvae in both species. This study has demonstrated that proteins in the partially purified L. purpureus extract have the potential to control storage pests in cereals transformed with L. purpureus defense-related genes, but the need for more studies regarding efficacy and safety is discussed.     

Competitiveness of native Bradyrhizobium japonicum strains in two different soil types

Interstrain competitiveness is a key factor affecting the performance of rhizobium inoculant. In the present study five native strains of Bradyrhizobium japonicum, namely SSF 4, SSF 5, SSF 6, SSF 7 and SSF 8, were assessed for their competitiveness in nodulating soybean using serological methods. The strains were inoculated individually or with the type strain USDA 110 at a 1:1 ratio. Nodule occupancy determined by immunofluorescence and dot immunoblot assay revealed that under in vitro conditions SSF 8 is more competitive than USDA 110 whereas the others were less competitive. The competitive ability of these strains was also estimated in pot culture in the field. In red soil both SSF 8 and USDA 110 were equally competitive whereas in black soil SSF 8 competed better than USDA 110 and produced more nodules. In a black soil field trial using a randomized block design, USDA 110 or SSF 8, when inoculated alone, occupied the majority of the nodules and enhanced nodule dry weight and shoot biomass. SSF 8 was more competitive when the strains were co-inoculated. Received: 1 November 1996     

Pomegranate enriched diet enhances the hematology, innate immune response, and disease resistance in olive flounder against Philasterides dicentrarchi

Olive flounder, Paralichythys olivaceus fed with pomegranate enriched diet and challenged with or without Philasterides dicentrarchi had a significantly higher white blood cell (WBC) count on weeks 2 and 4 than the infected group fed with non enriched diet (standard diet). Similarly the red blood cell (RBC) counts did not significantly change in control and treated fish on weeks 1 and 2. It was significantly increased in treated fish on week 2 when compared to the control. In both the groups the hemoglobin (Hb) and hematocrit (Ht) levels significantly increased on weeks 2 and 4. The mean corpuscular volume (MCV) did not significantly change at any time in both groups whereas mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) increased significantly on week 4 in the treated group. The leukocytes such as lymphocytes (Lym), monocytes (Mon), neutrophils (Neu), and biochemical parameters such as total protein (TP), glucose (GLU), and calcium (CAL) levels significantly increased in treated groups on week 2 or 4 as compared to the control. The scuticocidal activity and respiratory burst activity were significantly enhanced in treated groups with or without parasite on weeks 2-4. However, the serum lysozyme activity was significantly enhanced from weeks 1 to 4. The protective response in terms of cumulative mortality was low in groups fed with enriched diet against parasite when compared to control. Therefore, we suggest that pomegranate enriched diet following challenge with P. dicentrarchi restores the altered hematological and biochemical parameters, and improves the innate immune system in olive flounder against P. dicentrarchi.     

Molecular Discrimination of Eucalypt Clones Using the ISSR Marker System

Clonal forestry captures genetic gain generated by skillful selection and is now well recognized as a method for mass production of desired trees to obtain increased economic benefits. In Eucalyptus, clonal plantations have enhanced the productivity twofold, compared to plantations of unimproved seed origin. The present investigation was carried out to assess the genetic relationship of 41 eucalypt clones using the intersimple sequence repeat (ISSR) marker system. The ISSR-derived dendrogram and principal coordinate analysis (PCA) clustered 39 clones into two groups of E. camaldulensis and E. tereticornis in agreement with their taxonomic classification. Further, a total of three clone specific diagnostic markers and five unique profiles were identified using five ISSR primers. The eucalypt clones analyzed in the present investigations are derived from the breeding populations of both the species and are presently being used for large-scale plantation and hybridization studies. The molecular marker based clonal discrimination can be used to avoid duplication of clones and quality control of planting stock.

[Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Sustainable Forestry for the following free supplemental resource(s): ISSR Profiles of Eucalyptus Clones]     

华北地区不同规模畜禽养殖场粪便中抗生素抗性基因污染特征

为调查华北地区畜禽养殖环境抗生素抗性基因（ARGs）污染特征及影响因素,采集河北省和天津市不同规模的养猪场和养鸡场新鲜粪便样品,分析粪便中ARGs污染水平及有机质与ARGs含量的相关性。实时荧光定量PCR结果显示,不同种类畜禽养殖场粪便ARGs的相对丰度有显著区别,鸡粪中sul和erm基因的相对丰度高于猪粪,而编码核糖体保护蛋白的tet基因（4.24×10^-3~5.85×10^-1）在猪粪和鸡粪中的相对丰度无明显差异,均显著高于sul（1.07×10^-4~2.26×10^-1）、erm（6.36×10^-4~2.62×10^-1）以及编码外派泵蛋白和酶抑制剂的tet基因（1.24×10^-4~5.41×10^-2）。不同规模的养猪场粪便ARGs污染水平趋势为：中型 > 大型 > 小型,而不同规模养鸡场粪便中ARGs相对丰度无显著性差异（P=0.551）;此外,正交偏最小二乘判别（OPLS-DA）与典型相关分析（CCA）结果显示,畜禽粪便中编码核糖体保护蛋白的tet基因（tetM、tetO和tetW）相对丰度与有机碳（OC）和有机氮（ON）含量高度相关（VIP> 1）,sul基因则与OC/ON明显相关。综上,粪便中有机质和生物可利用碳氮比是影响畜禽养殖业ARGs污染水平的重要因素。