Genetic structure and mating system of Manilkara huberi (Ducke) A. Chev., a heavily logged amazonian timber species.

Made available in DSpace on 2018-06-07T00:56:27Z (GMT). No. of bitstreams: 1 esm074.pdf: 382618 bytes, checksum: c43090287fc020964cc9eac1fc180e79 (MD5) Previous issue date: 2008-02-1

Influência do tipo de corante na análise de danos mecânicos em sementes de milho (Zea mays L.).

xTrabalho apresentado no X Congresso Brasileiro de Sementes, 1997

Wide variability in the ICRISAT germplasm collections as a source for genetic enhancement of crop cultivars

Sustained gains in plant breeding rely on variation in crop gene pool. Therefore, it is essential to conserve crops’ diversity in situ and ex situ. Globally over 7.4 million germplasm accessions have been conserved in about 1750 genebanks. The greater use of germplasm diversity in crop improvement programmes could potentially broaden genetic base of crop cultivars. The ICRISAT genebank conserves over 128,000 germplasm accessions of six mandate crops (sorghum, pearl millet, finger millet, chickpea, groundnut, pigeonpea) and five small millets (foxtail millet, proso millet, barnyard millet, little millet and kodo millet). The collection is dominated with cultivated germplasm (97.7%) while wild and weedy relatives represent only 2.3%. Large variability was reported in the germplasm collections conserved at ICRISAT genebank, as revealed by characterization and evaluation of small subsets of total collection. However, large-scale evaluation to uncover hidden untapped potential is required to identify and introduce novel variability in to the crop improvement program

Características do pasto de capim-marandu irrigado sob sistemas de monocultura e silvipastoril em duas condições de pastejo.

Objetivou-se avaliar a altura, a massa de forragem e composição morfológica do pasto de capim Brachiaria brizantha cv. Marandu irrigado sob sistemas de monocultura e silvipastoril formado por coqueiros (Cocos nucifera) e vacas leiteiras, em duas condições de pastejo

Small ruminant lentiviruses: economic and productive losses, consequences of the disease.

Abstract: Small ruminant lentiviruses, caprine arthritis encephalitis virus, and Maedi-Visna virus cause diseases that result in significant productive losses, mostly in dairy animals. These viruses belong to the Retroviridae family, Lentivirus genus, and constitute a heterogeneous group, which may generate implications for the diagnosis and control of small ruminant lentiviruses. Losses caused by them are associated with reproductive failure, short productive life, and decreased milk production by the infected animals. In addition, these viruses may reduce milk quality, affecting the production of dairy products such as cheese. Small ruminant lentiviruses lead to indirect losses, decreasing herd value and forcing the development of epidemiological trade barriers for animal germplasm. Control of small ruminant lentiviruses is important to promote optimal milk production and to reduce costs with medicine and technical assistance. This control may vary in caprine and ovine populations of each country, according to seroprevalence, variety of breeds, and peculiarities of the practiced management. [Lentiviroses de pequenos ruminantes: perdas produtivas e econômicas, consequências da doença]. Resumo: Os lentivírus de pequenos ruminantes, o vírus da artrite encefalite caprina e o vírus Maedi-Visna causam enfermidades que ocasionam perdas produtivas significativas, principalmente em animais com aptidão leiteira. Esses vírus pertencem à família Retroviridae e ao gênero Lentivirus e formam um grupo genético heterogêneo, o que pode ocasionar implicações para o diagnóstico e o controle dos lentivírus de pequenos ruminantes. As perdas causadas pelos lentivírus de pequenos ruminantes estão relacionadas com falhas reprodutivas, vida produtiva curta e diminuição da produção leiteira dos animais infectados. Além disso, esses vírus podem promover a redução da qualidade do leite, afetando a produção de laticínios, tal como o queijo. Os lentivírus de pequenos ruminantes levam a perdas indiretas, reduzindo o valor dos rebanhos e forçando o desenvolvimento de barreiras comerciais epidemiológicas para germoplasma animal. O controle dos lentivírus de pequenos ruminantes é importante para promover uma maior produção de leite e reduzir os custos com medicamentos e assistência técnica. Esse controle pode variar de acordo com a população caprina e ovina de cada país em termos de soroprevalência, variedade de raças e particularidades do manejo adotado[ALICE ANDRIOLI PINHEIRO]

Variation for Photoperiod and Temperature Sensitivity in the Global Mini Core Collection of Sorghum

Information on photoperiod and temperature sensitivity of sorghum germplasm is important to identify appropriate sources for developing cultivars with a broad adaptation. The sorghum mini core collection consisting of 242 accessions along with three control cultivars were evaluated for days to 50% flowering (DFL) and plant height in two long-day rainy and two short-day post-rainy seasons, and for grain yield and 100-seed weight in the two post-rainy seasons. Differences in DFL and cumulative growing degree days (CGDD) in the rainy and post-rainy seasons were used to classify the accessions for photoperiod and temperature sensitivity. Results revealed 18 mini core landraces as photoperiod and temperature insensitive (PTINS), 205 as photoperiod sensitive and temperature insensitive (PSTINS), and 19 as photoperiod and temperature-sensitive (PTS) sources. The 19 PTS sources and 80 PSTINS sources took less DFL in the long-day rainy seasons than in the short-day post-rainy season indicating their adaptation to the rainy season and a possible different mechanism than that trigger flowering in the short-day sorghums. In all three groups, several accessions with desirable combinations of agronomic traits were identified for use in the breeding programs to develop climate-resilient cultivars and for genomic studies to identify genes responsible for the photoperiod and temperature responses

Variability in the Global Proso Millet (Panicum miliaceum L.) Germplasm Collection Conserved at the ICRISAT Genebank

Proso millet (Panicum miliaceum L.), also known as common millet or broomcorn millet, is an important ancient crop mostly grown for food, feed, and fodder purposes largely in China, Russia, India, and the USA. It is an under-researched and under-utilized crop. Over 29,000 germplasm accessions have been conserved in genebanks globally. Five races (miliaceum, patentissimum, contractum, compactum, ovatum) have been recognized in proso millet based on panicle morphology and shape. The genebank at the International Crops Research Institute for the Semi-Arid Tropics conserves 849 accessions of proso millet originating from 30 countries and represents all five races. Characterization of these germplasm accessions revealed large variability for morpho-agronomic traits, including for days to 50% flowering (26 to 50 days), plant height (20 to 133 cm), and inflorescence length (22 to 400 mm). On average, the race miliaceum was tall (62 cm) with long panicles (209 mm) and ovatum had short plants (46 cm) with small panicles (108 mm). The average Gower’s distance based on 18 morpho-agronomic traits on 841 accessions was 0.261. The race miliaceum had the highest among accessions within race average pairwise distance (0.254), while the distance was the lowest in ovatum (0.192). The races miliaceum and ovatum showed the highest divergence with each other (0.275), while the lowest divergence was observed between compactum and ovatum (0.229). Trait-specific sources were identified for early maturity, tall plants, long inflorescences, and greater seed size. The information on variability and trait-specific sources identified could potentially support proso millet improvement