ABSTRACT - Quantitative reverse transcription PCR (qRT-PCR) is a widely used method for transcript abundance analyses in plants. Relative quantification by qRT-PCR requires the use of a stably expressed reference gene. There are many ?housekeeping? genes reported in different plant species that are used as reference genes. However, it is important that the steady-state mRNA levels of these housekeeping genes are confirmed across different conditions and tissues in each species studied.

RESUMO - A presença de espinhos nas hastes e folhas das plantas de amoreira-preta dificulta o manejo cultural, como a poda e a colheita. O desenvolvimento de cultivares sem espinhos tem sido um dos principais objetivos dos programas de melhoramento desta cultura no mundo. Este trabalho teve como objetivo testar se há correlação entre a densidade e tamanho de espinhos dos genitores com a frequência de indivíduos sem espinhos nas suas progênies; além de comparar os genitores quanto ao número e tamanho de espinhos e testar a correlação entre esses caracteres.

Abstract:Context. It has been indicated that there might be an antagonism between selection for gastrointestinal nematode resistance and high productivity and feed conversion efficiency in ruminants. Aims. This study aimed to determine whether genetic selection for resistance to gastrointestinal nematodes would alter the feed intake and feed efficiency of sheep with or without an infection of Haemonchus contortus. Methods.

ABSTRACT. Embryo culture is a technique used to rescue immature embryos which would not germinate under natural conditions. However, one of the biggest problems of this process is the contamination by microorganisms. The objective of this work was to test asepsis methods and the use of PPMTM (Plant Preservative MixtureTM) in the culture medium for the germination and development of 'Precocinho' peach embryos.

ABSTRACT. Embryo culture is a technique used to rescue immature embryos which would not germinate under natural conditions. However, one of the biggest problems of this process is the contamination by microorganisms. The objective of this work was to test asepsis methods and the use of PPMTM (Plant Preservative MixtureTM) in the culture medium for the germination and development of 'Precocinho' peach embryos.

RESUMO - O morangueiro é uma frutífera de clima temperado pertencente ao grupo das pequenas frutas, sendo a de maior importância econômica no Brasil e no mundo. O tamanho das frutas é uma característica muito importante, pois influencia a cotação do produto, e está entre os caracteres que se busca melhorar dentro dos programas de melhoramento genético. O objetivo deste trabalho foi estimar a herdabilidade do caráter tamanho (diâmetro longitudinal e transversal) de frutas de morangueiro, no sentido amplo e restrito.

ABSTRACT: Chilling requirement is a characteristic that limits temperate fruit crops cultivation under a subtropical climate. Several mathematic models have been developed, differing on the relative value of chilling units, in order to estimate the chilling accumulation on a given site.

Abstract: Pre-slaughter fasting duration affect blood parameters related to stress and metabolism, decrease live and carcass weights and impact beef quality of cattle. In three experiments, 1100 steers and heifers, finished on feedlot or on pasture, were evaluated to assess the influence of the site and duration of fasting before slaughter on physiological, carcass and meat quality traits. Cattle were allocated to one of two fasting duration - long (23?29 h) or short (2?6 h) ? and to one of two sites of fasting? farm or abattoir.

Abstract: The Century model was used to simulate soil carbon (C) and nitrogen (N) cycling, and crop production dynamics in an ongoing field experiment in Uruguay (started in 1963). The model was calibrated using observed data from three treatments (crop or crop?pasture rotations) and validated with a fourth treatment. The model correctly predicted the impact of different treatments on microbial biomass, N mineralization, soil respiration, and crop yields.