horticultura horticultura brasileira brasileira O morangueiro é cultivado e apreciado nas mais variadas regiões do mundo (Resende et al., 1999). A grande popularidade se deve aos esforços dos melhoristas que, desde o século passado, têm desenvolvido cultivares adaptadas às mais diversas condições ambientais (Hancock et al., 1996).A produção do morango é quase toda voltada para o mercado doméstico do Brasil, sendo cerca de 70% destinada ao consumo in natura e 30% ao processamento. Em 2006 o país produziu cerca de 100 mil toneladas, cultivadas numa área próxima a 3.500 ha (Antunes & Réisser Júnior, 2007).Para Ronque (1998) RESUMOA introdução da cultura do morangueiro no norte de Minas Gerais pode ser uma alternativa viável para a diversificação da produção agrícola local. O clima quente e seco da região pode diminuir a incidência de doenças, aumentando a produtividade e a qualidade dos morangos. O trabalho teve o objetivo de avaliar o desempenho produtivo e a qualidade pós-colheita dos frutos das cultivares de morangueiro Campinas IAC-2712, Sweet Charlie e Dover, cultivados no norte de Minas Gerais. Para determinar o desempenho produtivo foram avaliados o número, a massa fresca média e a produtividade de frutos no campo experimental. O delineamento estatístico utilizado foi de blocos ao acaso com três tratamentos e quatro repetições, sendo as parcelas constituídas de 21 plantas. A qualidade pós-colheita foi determinada em laboratório, avaliando-se o comprimento, diâmetro, firmeza, pH, sólidos solúveis, acidez titulável, açúcares redutores e açúcares totais dos frutos. Adotou-se o delineamento estatístico inteiramente casualizado com três tratamentos, quatro repetições e parcelas de 24 frutos. As análises foram realizadas no início, meio e fim do ciclo da cultura. A cultivar Dover apresentou os maiores índices de produtividade, maior número de frutos e maior massa fresca média destes. Já a Sweet Charlie foi a segunda mais produtiva e a Campinas IAC-2712 apresentou a menor produtividade. As características físico-químicas dos frutos mantiveram-se dentro dos padrões quando comparadas com as dos frutos produzidos em outras regiões. Concluiu-se que as cultivares Dover e Sweet Charlie apresentam potencial produtivo e qualitativo para serem cultivadas no norte de Minas Gerais.Palavras-chave: Fragaria x ananassa, cultivares, clima tropical, produtividade, qualidade pós-colheita. ABSTRACT Productivity and quality of strawberry cultivars in the north of Minas Gerais stateThe introduction of strawberry crop in northern Minas Gerais state, Brazil, can be a viable alternative for the diversifying local agricultural production. The hot and dry climate of the region can reduce disease incidence, increasing productivity and quality of strawberries. We evaluated productivity and quality of fruits of the cultivars Campinas IAC-2712, Sweet Charlie and Dover in northern Minas Gerais State, Brazil. To determine performance and productivity, number, average fresh mass and production of fruits were evaluated in a field experiment. The...

The resistance of 24 potato genotypes to B. tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) was evaluated in five greenhouse experiments. The first experiment we evaluated the attractiveness and preference for oviposition in a free-choice test (randomized blocks, 24 treatments, and eight replications). In two other experiments we evaluated no-choice preference for oviposition (randomized blocks, six treatments, and ten replications). The whitefly egg-adult cycle was monitored using a statistical design in randomized blocks with five replications. Trichome density was evaluated in an experiment with 24 treatments and six replications, in a completely randomized design. In the free-choice test, potato genotypes NYL 235-4 and IAC-1966 were the most attractive to adults, while cultivars Achat, Aracy Ruiva, and Monte Bonito presented the lowest number of adults. Also in this assay, cultivars Achat, Ibituaçu, Panda, IAC-1966, and Agata presented the lowest number of eggs, while in the no-choice test, only cultivar Achat and IAC-1966 remained resistant. Consequently, for these two genotypes non-preference is the oviposition resistance mechanism. The egg-adult cycle varied from 21 days (cultivar Panda) to 22.5 days (clones IAC-1966 and NYL 235-4). The adult emergence varied from 91.2% (clone IAC-1966) to 99.3% (cultivar Ibituaçu). Clone NYL 235-4 had the greatest number of simple (ST) and glandular (GT) trichomes; while clone IAC-1966 had the lowest number of ST and, clone IAC-6290, of GT. There were significant correlations between adult attractiveness and oviposition preference; between oviposition preference and ST density; and between oviposition preference and GT density. Considering all characteristics, cultivar Achat was the most resistant to B. tabaci biotype B among all potato genotypes studied, while clone NYL 235-4 proved (past tense) to be susceptible.

Maintenance of the volume and osmolality of body fluids is important, and the adaptive responses recruited to protect against osmotic stress are crucial for survival. The objective of this work was to compare the responses that occur in aging male and female rats during water deprivation. For this purpose, groups of male and female Wistar rats aged 3 mo (adults) or 18 mo (old) were submitted to water deprivation (WD) for 48 h. The water and sodium (0.15 M NaCl) intake, plasma concentrations of oxytocin (OT), arginine vasopressin (AVP), corticosterone (CORT), atrial natriuretic peptide (ANP), and angiotensin II (ANG II) were determined in hydrated and water-deprived animals. In response to WD, old male and female rats drank less water and saline than adults, and both adult and old females drank more water and saline than respective males. Dehydrated old animals displayed lower ANG II plasma concentration and CORT response compared with the respective normohydrated rats. Dehydrated adult males had higher plasma ANP and AVP as well as lower CORT concentrations than dehydrated adult females. Moreover, plasma OT and CORT levels of old female rats were higher than those in the dehydrated old male rats. Relative expression of ANG II type 1 receptor mRNA was decreased in the subfornical organ of adult and old male rats as well as adult female rats in response to WD. In conclusion, the study elucidated the effect of sex and age on responses induced by WD, altering the degree of dehydration induced by 48 h of WD.

Excessive sodium (Na+) intake in modern society has been associated with several chronic disorders such as hypertension. Several studies suggest that early life events can program physiological systems and lead to functional changes in adulthood. Therefore, we investigated behavioral and neuroendocrine responses under basal conditions and after 48 h of water deprivation in adult (60‐day‐old Wistar rats) male, Wistar rats originating from dams were offered only water or 0.15 mol/L NaCl during pregnancy and lactation. Early life salt exposure induced kidney damage, as shown by a higher number of ED‐1 positive cells (macrophages/monocytes), increased daily urinary volume and Na+ excretion, blunted basal water intake and plasma oxytocin levels, and increased plasma corticosterone secretion. When challenged with water deprivation, animals exposed to 0.15 mol/L NaCl during early life showed impaired water intake, reduced salt preference ratio, and vasopressin (AVP) secretion. In summary, our data demonstrate that the perinatal exposure to excessive Na+ intake can induce kidney injury in adult offspring and significantly affect the key mechanisms regulating water balance, fluid intake, and AVP release in response to water deprivation. Collectively, these novel results highlight the impact of perinatal programming on the homeostatic mechanisms regulating fluid and electrolyte balance during exposure to an environmental stress (i.e. dehydration) in later life.

Aging is a complex biological process, resulting in gradual and progressive decline in structure and function in many organ systems. Our objective is to determine if structural changes produced by aging vary with sex in a stressful situation such as dehydration. The expression of Slc12a3 mRNA in the renal cortex, α-smooth muscle actin (α-SMA), and fibronectin was evaluated in male and female rats, aged 3 and 18 months, submitted and not submitted to water deprivation (WD) for 48 h, respectively. When comparing ages, 18-month-old males showed a lower expression of Slc12a3 mRNA than 3-month-old males, and control and WD 18-month-old male and female rats exhibited a higher expression of α-SMA than the respective 3-month-old rats. Fibronectin was higher in both control and WD 18-month-old males than the respective 3-month-old males. In females, only the control 18-month-old rats showed higher fibronectin than the control 3-month-old rats. When we compared sex, control and WD 3-month-old female rats had a lower expression of Slc12a3 mRNA than the respective males. The WD 18-month-old male rats presented a higher expression of fibronectin and α-SMA than the WD 18-month-old female rats. When we compared hydric conditions, the WD 18-month-old males displayed a lower relative expression of Slc12a3 mRNA and higher α-SMA expression than the control 18-month-old males. Aging, sex, and dehydration lead to alterations in kidney structure.