Heterotic effects in triploid watermelon hybrids.

Twelve experimental triploid hybrids were evaluated to estimate heterotic effects for some plant and fruit traits in triploid watermelon (Citrullus lanatus). Tiffany, a triploid hybrid was used as standard cultivar. The experiment in a randomized block design was carried out in three replications at the Experimental Station of Embrapa Semi-Árido in Petrolina, state of Pernambuco. The following traits were evaluated: earliness, prolificacy, main stem length, fruit weight, soluble solid content, rind thickness, flesh color, and hollow heart disorder. All evaluated traits presented significant variability among the hybrids. Mid-parent heterosis effects were found as well as the standard cultivar ranging from negative to positive values attaining up to 300% prolificacy in some cases. The tetraploid lines should be improved for several traits in order to produce earlier triploid hybrids with more compact plants and fruits without the hollow heart disorder

Re-defining the Golgi complex in Plasmodium falciparum using the novel Golgi marker PfGRASP

Plasmodium falciparum, the causative agent of malaria, relies on a sophisticated protein secretion system for host cell invasion and transformation. Although the parasite displays a secretory pathway similar to those of all eukaryotic organisms, a classical Golgi apparatus has never been described. We identified and characterised the putative Golgi matrix protein PfGRASP, a homologue of the Golgi re-assembly stacking protein (GRASP) family. We show that PfGRASP is expressed as a 70 kDa protein throughout the asexual life cycle of the parasite. We generated PfGRASP-GFP-expressing transgenic parasites and showed that this protein is localised to a single, juxtanuclear compartment in ring-stage parasites. The PfGRASP compartment is distinct from the ER, restricted within the boundaries of the parasite and colocalises with the cis-Golgi marker ERD2. Correct subcellular localisation of this Golgi matrix protein depends on a cross-species conserved functional myristoylation motif and is insensitive to Brefeldin A. Taken together our results define the Golgi apparatus in Plasmodium and depict the morphological organisation of the organelle throughout the asexual life cycle of the parasite

Heterotic effects in triploid watermelon hybrids.

Twelve experimental triploid hybrids were evaluated to estimate heterotic effects for some plant and fruit traits in triploid watermelon (Citrullus lanatus). Tiffany, a triploid hybrid was used as standard cultivar. The experiment in a randomized block design was carried out in three replications at the Experimental Station of Embrapa Semi-Árido in Petrolina, state of Pernambuco. The following traits were evaluated: earliness, prolificacy, main stem length, fruit weight, soluble solid content, rind thickness, flesh color, and hollow heart disorder. All evaluated traits presented significant variability among the hybrids. Mid-parent heterosis effects were found as well as the standard cultivar ranging from negative to positive values attaining up to 300% prolificacy in some cases. The tetraploid lines should be improved for several traits in order to produce earlier triploid hybrids with more compact plants and fruits without the hollow heart disorder

Capacidade de combinação de linhagens avançadas e cultivares comerciais de melancia.

A análise da capacidade de combinação é uma ferramenta importante na estimação de parâmetros úteis ao melhoramento genético da melancieira; pois, auxilia na escolha de genitores, cruzamentos promissores e possibilita a caracterização da natureza e da magnitude da interação gênica envolvida na expressão dos caracteres de importância agronômica. Desse modo, o presente trabalho objetivou estimar os efeitos das capacidades de combinação geral (CGC) e específica (CEC), em seis genitores de melancia e seus nove híbridos, provenientes de um esquema de cruzamentos dialélicos parciais. O experimento foi realizado na Estação Experimental da Embrapa Rondônia, em Machadinho do Oeste-RO, no período de março a junho de 2005. Os genitores foram divididos em dois grupos, sendo o primeiro formado pelas linhagens Cpafro 34.305, Cpafro 74.105 e Cpafro 45.202, e o segundo, pelas cultivares comerciais ?Charleston Gray?, ?Sugar Baby? e ?Omaru Yamato?. O desempenho dos tratamentos (genitores + híbridos) foi avaliado quanto a 11 caracteres agronômicos, utilizando-se delineamento em blocos ao acaso, com três repetições e parcelas de sete plantas. Os efeitos da CGC foram superiores aos da CEC para a maioria das características estudadas, evidenciando a predominância do efeito aditivo no controle gênico das mesmas. Na maioria dos genitores, foram verificados efeitos de CGC favoráveis ao melhoramento da cultura, sendo ?Sugar Baby? e ?Charleston Gray? os genótipos mais promissores para uso em estratégias de melhoramento intrapopulacional visando a obtenção de cultivares de frutos pequenos e grandes, respectivamente. Com base na CEC, as combinações híbridas superiores e portanto, com maior potencial de aproveitamento comercial foram Cpafro 74.105 x Sugar Baby, de frutos pequenos e Cpafro 74.105 x Charleston Gray, de frutos grandes

Avaliação de descritores morfológicos de folha e flor em acessos de melancia.

O presente trabalho objetivou avaliar descritores morfológicos de folha e flor, em acessos de melancia. O experimento foi realizado no campo experimental da Embrapa Rondônia, localizado em Porto Velho ? RO. Os tratamentos foram compostos pelas c ultivares ?Charleston Gray?, ?Sugar Baby?, ?Kodama? e por 15 acessos da coleção ativa de germoplasma da Embrapa Semiárido. Empregou-se o delineamento de blocos casualizados com três repetições e parcelas de seis plantas. Em cada parcela foram amostradas cinco folhas, cinco flores masculinas e cinco flores femininas para determinação da largura e comprimento foliar (LFH e CFH); relação CFH/LFH; diâmetro da corola em flores masculinas (DCM) e femininas (DCF); diâmetro e comprimento do ovário (DOV e COV) e relação COV/DOV. Os dados foram submetidos à análise de variância e as médias foram comparadas por meio do teste de Scott & Knott. As variáveis LFH, CFH, CFH/LFH, DCM, DCF, DOV, COV, COV/DOV apresentaram, respectivamente, as seguintes médias: 19,19 cm, 21,18 cm; 1,11; 3,06 cm; 2,37 cm; 0,86 cm; 1,25 cm e 1,48. Foram verificadas diferenças significativas entre os tratamentos apenas para as variáveis DCF, DOV, COV e COV/DOV, indicando que a folha e a flor masculina não foram descritores apropriados para a caracterização do germoplasma avaliado. lanatu

SUBMISSION OF ALLEGED AND UNLIVED SYSTEMS TO PROVIDE HEAT TRANSFER EFFICIENCY

The study presented is based on two automotive fin and non-fin heads made of cast aluminum that were subjected to an indirect heating called conduction and convection by means of a rectangular equipment constructed of 2mm 1020 carbon steel plate, isolated in its bases. and side by means of a 10mm thick ceramic fiber blanket sandwich, subjected to an internal heat source, a 3,000 watt finned heater, which conducted conductive and convective heat to the top cover where the heads were housed, the fin side and the non fin side. The heating was controlled by thermostat, which when it reached its highest value, was turned off and the calibration made using fans until reaching the ambient temperature. Temperature data were collected by a PICO TECH-TC-08 data entry plate, viewed on the computer through the card software and compared between both fin and non-fin heads by means of “K” thermocouples glued to each silicon block and their respective instrumentation, so that the temperature sensors were strategically positioned to prove the study. After analyzing and discussing the results, it is observed that finned bodies under this operating condition and constructive aspects allowed a better thermal exchange with the medium, producing a higher efficiency between 5 and 12%