The Potential Of High-Resolution BAC-FISH In Banana Breeding

Abstract The genetic complexity in the genus Musa has been subject of study in many breeding programs worldwide. Parthenocarpy, female sterility, polyploidy in different cultivars and limited amount of genetic and genomic information make the production of new banana cultivars difficult and time consuming. In addition, it is known that part of the cultivars and related wild species in the genus contain numerous chromosomal rearrangements. In order to produce new cultivars more effectively breeders must better understand the genetic differences of the potential crossing parents for introgression hybridization, but extensive genetic information is lacking. As an alternative to achieve information on genetic collinearity we make use of modern chromosome map technology known as high-resolution fluorescent in situ hybridization (FISH). This article presents the technical aspects and applications of such a technology in Musa species. The technique deals with BAC clone positioning on pachytene chromosomes of Calcutta 4 (Musa acuminata ssp. burmanicoides, A genome group, section Eumusa) and M. velutina (section Rodochlamys). Pollen mother cells digestion with pectolytic enzymes and maceration with acetic acid were optimized for making cell spread preparations appropriate for FISH. As an example of this approach we chose BAC clones that contain markers to known resistance genes and hybridize them for establishing their relative positions on the two species. Technical challenges for adapting existing protocols to the banana cells are presented. We also discuss how this technique can be instrumental for validating collinearity between potential crossing parents and how the method can be helpful in future mapping initiatives, and how this method allows identification of chromosomal rearrangements between related Musa species and cultivar

An effective dna extraction method from Cajanus cajan seeds suitable for pcr analysis.

Abstract: The presence of co-extracted impurities in seeds can make DNA extraction challenging, as these contaminants can interfere with PCR amplification, both of which, extraction and PCR, are important steps for ongoing breeding and selection programs. A new protocol is evaluated in this study as an alternative for extracting DNA from embryonic radicle tips of pigeonpea seeds that yield DNA readily amenable to PCR. The proposed protocol showed great promise as an alternative method, as it is low-cost, straightforward, and effective for PCR amplification. It also has the advantage of not requiring hazardous or expensive reagents and can be easily scaled up, demonstrating its potential as a valuable resource for scientists studying pigeonpea genetics and breeding. Resumen: Un método efectivo de extracción de ADN en semillas de guandú (Cajanus cajan) adecuado para análisis por PCR La presencia de impurezas extraídas conjuntamente en las semillas puede dificultar la extracción de ADN, ya que estos contaminantes pueden interferir con la amplificación por PCR; ambos procesos son pasos importantes en los programas de reproducción y selección. En este estudio se evaluó un nuevo protocolo como alternativa para extraer ADN de los ápices de la radícula embrionaria de semillas de guandú, las cuales producen ADN fácilmente adecuado para la PCR. El protocolo propuesto mostró un gran potencial como método alternativo, ya que es económico, sencillo y efectivo para la amplificación por PCR. También tiene la ventaja de que no requiere reactivos costosos o peligrosos y puede ampliarse fácilmente, lo que demuestra su potencial como un recurso valioso para los científicos que estudian la genética y el mejoramiento del guandú

Estudo do reflexo de subir como parâmetro do desenvolvimento físico de filhotes expostos perinatalmente ao fungicida fenarimol.

Foram realizados estudos sobre o desempenho de filhotes de ratos Wistar testados quanto ao reflexo de subir, medido em segundos. Esses filhotes foram expostos perinatalmente ao fungicida fenarimol. A técnica utilizada para avaliar os efeitos dos fatores (fase de prenhez/lactação e dose do fungicida) e de suas interações na resposta foi modelo não paramétrico para medidas repetidas. Verificamos dos resultados obtidos que há efeito do fator tempo e da interação entre os fatores dose do fungicida e fase de exposição das ratas-mães no score do reflexo dos filhotes. Nas comparações múltiplas verificamos quais combinações de níveis de fase e dose foram responsáveis pela significância da interação das mesmas

ENERGY STUDY OF A HEAT PUMP USED FOR AIR ( HEATING AND DEHUMIDIFICATION

Heat pump assisted dryers can realize considerable savings of primary energy as compared with conventionally-heated air drying. This manuscript analyzes the design and construction aspects of a heat pump assisted dryer for biological products. The performance of the heat pump is investigated through an energy analysis, carried out under operating conditions of practical interest. The system is operated using R22 and is also evaluated with respect to the coefficient of performance (COP). Although the current trend is to invest in low-energy, low-carbon technologies, heat pump assisted dryers remain underexplored in the industrial sector due to its more complex operation