Recent advances in molecular genetic linkage maps of cultivated peanut

The competitiveness of peanuts in domestic and global markets has been threatened by losses in productivity and quality that are attributed to diseases, pests, environmental stresses and allergy or food safety issues. Narrow genetic diversity and a deficiency of polymorphic DNA markers severely hindered construction of dense genetic maps and quantitative trait loci (QTL) mapping in order to deploy linked markers in marker-assisted peanut improvement. The U.S. Peanut Genome Initiative (PGI) was launched in 2004, and expanded to a global effort in 2006 to address these issues through coordination of international efforts in genome research beginning with molecular marker development and improvement of map resolution and coverage. Ultimately, a peanut genome sequencing project was launched in 2012 by the Peanut Genome Consortium (PGC). We reviewed the progress for accelerated development of peanut genomic resources in peanut, such as generation of expressed sequenced tags (ESTs) (252,832 ESTs as December 2012 in the public NCBI EST database), development of molecular markers (over 15,518 SSRs), and construction of peanut genetic linkage maps, in particular for cultivated peanut. Several consensus genetic maps have been constructed, and there are examples of recent international efforts to develop high density maps. An international reference consensus genetic map was developed recently with 897 marker loci based on 11 published mapping populations. Furthermore, a high-density integrated consensus map of cultivated peanut and wild diploid relatives also has been developed, which was enriched further with 3693 marker loci on a single map by adding information from five new genetic mapping populations to the published reference consensus map

Avaliação de espécies silvestres e cultivares de amendoim para resistência a Enneothrips flavens Moulton

No Brasil, diversas pragas podem atacar o amendoinzeiro, sendo o tripes-do-prateamento, Enneothrips flavens Moulton (Thysanoptera: Thripidae), a principal delas. Com o objetivo de avaliar a infestação e os sintomas dessa praga em diferentes acessos de espécies silvestres, anfidiplóides e cultivares de amendoinzeiro, foi instalado um experimento em campo, no município de Pindorama (SP ), no ano agrícola de 2007/2008. O delineamento estatístico adotado foi o de blocos ao acaso, com 48 tratamentos e cinco repetições. A formação das mudas foi feita em copos com substrato em casa de vegetação, sendo o plantio realizado em outubro/novembro de 2007. Foram realizadas amostragens a partir dos 30 dias após o plantio das mudas no campo, repetidas a cada 15 dias, num total de cinco avaliações, em cinco folíolos fechados por planta. Foram anotadas a presença e ausência de tripes em folíolos ainda fechados e atribuídas notas dos sintomas de dano aos folíolos recém-abertos, baseando-se em uma escala de notas variando de 1 a 5, sendo nota 1 sem dano de ataque; nota 2 limbo foliar com 1% a 25% da superfície com estrias e deformações; nota 3, 26 a 50%; nota 4, 51 a 75%; e, nota 5, 76% a 100%. Os acessos com menor porcentagem de presença de tripes e notas de sintomas foram VS 14957 (A. gregoryi), V13832 (A. stenosperma), V8979 (A. kuhlmannii), V9912 (A. kuhlmannii), V7639 (A. kuhlmannii) e VMiIrLbGv14309 (A. villosa). Dentre os acessos mais sensíveis ao tripes situaram-se V12549 (Arachis hypogaea),Ac2562 (A. hypogaea) e as cultivares IAC Caiapó (A. hypogaea) e IA C Runner 886 (A. hypogaea)

Biogeography of wild Arachis: Assessing conservation status and setting future priorities

The conservation status of wild Arachis spp. is not well characterized for its maintenance and possible future exploitation for the improvement of cultivated peanut, Arachis hypogaea L. Our objectives were to use 2175 georeferenced observations of wild peanut (Arachis spp.) to assess the conservation status of the genus and to prioritize biologically and geographically future conservation actions. Species distribution predictions were made on the basis of 36 climate variables, and these data were synthesized with land-use data to map the potential distribution of each species, and hence the species richness of the whole genus, excluding A. hypogea. hotspots of species richness were found in Mato Grosso around Cuiaba and Campo Grande in Brazil and around the Serra Geral de Goias, northeast of Brasilia. The current state of in situ conservation areas poorly represents wild peanut, with only 48 of the 2175 observations from National Parks. Several species were identified as being under threat of extinction. These included A. archeri Krapov. & W.C. Gregory, A. setinervosa Krapov. & W.C. Gregory, A. marginata Gardner, A. hatschbachii Krapov. & W.C. Gregory, A. appressipila Krapov. & W.C. Gregory, A. villosa Benth., A. cryptopotamica Krapov. & W.C. Gregory, A. helodes Martius ex Krapov. & Rigoni, A. magna W.C. Gregory & C.E. Simpson, and A. gracilis Krapov. & W.C. Gregory (identification based on highly restricted ranges and land-use pressures); and A. ipaensis Krapov. & W.C. Gregory, A. cruziana Krapov., W.C. Gregory & C.E. Simpson, A. williamsii Krapov. & W.C. Gregory, A. martii Handro, A. pietrarellii Krapov. & W.C. Gregory, A. vallsii Krapov. & W.C. Gregory, and A. monticola Krapov. & Rigoni (identification based on insufficient observations and land-use pressures). It is suggested that ex situ conservation efforts should focus on the area around Pedro Gomes (300 km southeast of Cuiaba), 170 km south along the planned road from Cuiaba to Corumba, and around San Jose de Chiquitos in Bolivia, where some of the species adapted to lower temperatures may be found

Variabilidade isoenzimática em oito raças de milho Isoenzyme variation among eight races of maize

Com o objetivo de avaliar a variabilidade genética e as relações de afinidade entre dezenove populações de oito raças de milho (Zea mays L.) - as comerciais antigas Cateto Sulino, Cateto Sulino Grosso, Cateto Nortista e Canario de Ocho, e as raças indígenas Moroti, Lenha, Entrelaçado e Caingang - analisaram-se os seguintes sistemas enzimáticos: glutamato oxalacetato transaminase (GOT), esterase (EST) e malato desidrogenase (MDH). Observou-se maior semelhança entre as raças pertencentes a um mesmo grupo, mas as populações analisadas não se agruparam de acordo com as raças, classificadas anteriormente segundo caracteres morfológicos. Os sistemas enzimáticos utilizados não permitiram a caracterização individual de cada uma das raças analisadas. As indígenas apresentaram maior variabilidade do que as comerciais antigas quanto ao número de alelos por loco e à porcentagem de locos polimórficos.<br>The objective of this study was to evaluate the genetic variability and affinity relationships among eight races of maize (Zea mays L.): four ancient varieties (Cateto Sulino, Cateto Sulino Grosso, Cateto Nortista and Canario de Ocho) and four indigenous (Moroti, Lenha, Entrelaçado and Caingang), through isoenzymatic polymorphisms. The following isoenzymatic systems were evaluated: Glutamate Oxaloacetate Transaminase (GOT), Esterase (EST) and Malate Dehydrogenase (MDH). It was observed a higher identity among races belonging to the same racial group; however, populations within each race were not grouped according, to previous morphological classification. Indigenous races showed higher average number of alleles per loci and percentage of polymorphic loci than the ancient varieties. This fact might be due to the selection the ancient varieties had been gone through