Evaluation of inbred lines, commercial materials, and two maize populations for aluminum tolerance

Avaliação da tolerância a Al (4,5 mg/l) de 39 linhagens, 98 materiais comerciais, 167 progênies de uma população IAC-Maya e de 466 progênies de uma população IAC-Taiuba de milho (Zea mays L), usando-se a técnica de solução nutritiva. Foram utilizados os seguintes índices: ICR (índice de crescimento da radícula), determinado através da multiplicação dos índices CRR  (comprimento relativo da radícula) e CRRSML (comprimento relativo da raiz secundária mais longa), e CLR (comprimento líquido da radícula) calculado pela diferença entre os valores de CR (comprimento da radícula) obtidos no inicio e fim do período de crescimento das plantas em presença de alumínio. Os índices CRR e CRRSML foram 4erivados da relação obtida entre os valores obtidos na presença e ausência de Al. As linhagens e as progênies da população IAC-Maya foram avaliadas através do ICR, enquanto os demais o foram pelo índice CLR. Os materiais controles foram IAC HS1227 (tolerante a Al) e IAC HS7777 (sensível a Al). O método de solução nutritiva foi eficiente na diferenciação da tolerância a Al dentre os materiais testados, evidenciando a ocorrência de ampla variabilidade genética para essa característica. As seguintes linhagens e materiais comerciais apresentaram tolerância ao Al (4,5 mg/l): Porto Rico 70.D.2, Ip 48-5-3, Ip 365-4-1, IA 2992-3-1-2-3, Viç 3-2-3-30-V-6,490,519, 532, 535-2 e 820 (linhagens) e AG 82, AG 260, AGROMEM 1022, ASGROW 1255, DINA 03 5, DINA 47, IAC Hmd 7974,SS 1243 e UNICAMP 720 (materiais comerciais).The evaluation of 39 inbred lines, 98 commercial materials, 167 progenies from, an IAC-Maya population, and 466 progenies from an IAC-Taiuba population of maize (Zea mays L.) for Al tolerance in nutrient solutions was carried out. The following root characteristics were use: CRI (growth radicle index), determined by multiplying RRL (relative radicle length) and RLLSR (relative length of the longest secondary root), and NRL (net radicle length) estimated by the difference between the measurements of RL (radicle length) obtained at the beginning and at the end of the growth period in Al-stressed nutrient solutions. Both indices RRL and RLLSR were determined by dividing the values obtained in solutions with and no added Al. The characteristic GRI was used to evaluate the inbred lines and the IAC-Maya populations, while NRL was used for the commercial materials. The control materials were IAC HS 1227 (Al tolerant) and IAC HS 7777 (Al susceptible). The nutrient solution technique was efficient to differentiate Al tolerance among the maize genotypes tested. A wide genetic variability was found regarding the Al tolerance trait among the maize genotypes tested. The following maize inbred lines and commercial materials were tolerant to Al (4,5 mg/l): Porto Rico 70.D.2, Ip 48-5-3, Ip 365-4-1, IA 2992-3-1-2-3, Viç 3-2-3-30-V-6, 490, 519, 532, 535-2, and 820 (inbred lines) and AG 82, AO 260, AGROMEM 1022, ASGROW 1255, DINA 03S, DINA 47, IAC Hmd 7974, SS 1243, and UNICAMP 720 (commercial materials)

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015

Differential responses of sorghum genotypes for tolerance to aluminum in nutrient solutions

Neste trabalho utilizou-se uma técnica de solução nutritiva para identificar, dentre 391 linhagens de sorgo (181 do BAG-sorgo, 71 do CNPMS, 17 do SEPON/ICRISAT, e 122 da coleção de sorgo sacarino), os genótipos que apresentam tolerância ao alumínio. A avaliação do comportamento diferencial dessas linhagens baseou-se no crescimento da raiz seminal primária de plantas jovens de sorgo, em solução nutritiva contendo níveis variados de Al (0,0; 2,25; e 4,5 mg de Al/l para sorgo granífero e 0,0; 2,5; e 5,0 mg de Al/l para sorgo sacarino). A característica usada para a comparação entre genótipos foi o comprimento relativo da raiz seminal (CRSS = CRS+Al/CRS-Al onde CRS = comprimento da raiz seminal). Baseando-se na distribuição percentual dos valores de CRRS, obtidos nas diferentes linhagens, e nos valores de CRRS, encontrados nos materiais controles SC 208 (sensível ao Al) e SC 283 (tolerante ao Al), três classes de resposta ao alumínio foram identificadas: sensível (CRRS 0,70). Dentre os materiais avaliados as seguintes linhagens apresentaram tolerância aos níveis de 4,5 ou 5,0 mg de Al/l: IS 3625, IS 7173 C (SC 283), IS 12666, 5DX61/6/2, 3DX57/1/1/910, 156-P-5-Serere-1, 9DX9/11, Brandes, MN 4004 e MN 1204. O processo mostrou-se eficiente na avaliação de grande número de linhagem, quando se visa a tolerância ao alumínio, sendo recomendada como técnica auxiliar em programas de melhoramento.A nutrient solution technique was used to screen 391 sorghum genotypes (181 from BAG-sorghum, 71 from CNPMS, 17 SEPON from ICRISAT and 122 from sweet sorghum collection) for Al tolerance. The differential behavior was based on the root growth of young sorghum plant grown in nutrient solutions with varied Al (0.0, 2.25 and 4.5 mg of Al/l for grain sorghum and 0.0, 2.5 and 5.0 mg of Al/l for sweet sorghum). For comparison purposes, the relative seminal root length (SRRL = SRL+Al/SRL-Al, where SRL = Seminal Root Rength and SRRL = Seminal Root Relative Length) was estimated. Based upon the percentual frequency distribution of SRRL values obtained for the different genotypes tested and based upon the SRRL values of SC 208 (Al susceptible) and SC 283 (Al-tolerant) three classes of differential responses to Al were identified: Susceptible (SRRL 0.70). Among the materials tested, the following were classified as being tolerant to Al: IS 3625,IS 7173 C (SC 283) IS 12666, 5DX61/6/2, 3DX57/1/1/91O, 156-P-5-Serere-1, 9DX9/11, Brandes, MN 4004 and MN 1204. The technique proved to be effective to screen large number of line for Al tolerance and should be used as a tool in a breeding program