Reciprocal Recurrent Selection in the Breeding of \u3cem\u3eBrachiaria decumbens\u3c/em\u3e

Pastures of Brachiaria decumbens cv. Basilisk radically changed the scenario of livestock production in central Brazil in the early 1970s and in fact, promoted the development of this vast region. However, despite the reasonable biomass yields and nutritional value when grown on these tropical acid soils, its susceptibility to grassland spittlebugs has limited its use. The breeding of B. decumbens in Brazil has been restricted to interspecific crosses using cv. Basilisk as a pollen donor due to the lack of compatible sexual ecotypes within this species. Recently, the successful chromosome duplication of a sexually reproducing diploid accession produced 3 successful events (Simioni and Valle 2009), enabling intraspecific crosses. This paper reports the onset of the research to obtain superior apomictic hybrids in B. decumbens using reciprocal recurrent selection (RRS), a cyclic breeding strategy

Agronomic and Nutritional Evaluation of Intraspecific Crosses in \u3cem\u3eBrachiaria decumbens\u3c/em\u3e

Brachiaria decumbens cv. Basilisk is the single most important forage grass used for pastures in the tropics. This cultivar has exceptional adaptation to acid soils, vigorous growth, ease of establishment, and good forage value throughout the year, but these favourable characteristics are counteracted by its susceptibility to insect pests such as spittlebug. Breeding to produce improved cultivars within this species was impossible until 2009 due to the lack of compatible sexual ecotypes. With the success of somatic chromosome duplication of sexually reproducing diploid plants of B. decumbens (Simioni and Valle 2009), intraspecific crosses with natural apomictic tetraploid accessions were finally possible. This paper reports the results of the agronomic and nutritional evaluation of 50 preselected intraspecific hybrids of B. decumbens

Effect of Season and Year of Evaluation in the Selection of \u3cem\u3eBrachiaria humidicola\u3c/em\u3e Hybrids

Brachiaria humidicola is well adapted to infertile and acid soils with poor drainage or temporary flooding (Keller-Grein et al. 1996). It is widely used in Brazil in wetlands and areas of marginal land characterised by waterlogged soils. During the evaluation stages of the breeding program of this species, genotypes are generally tested using consecutive cuts within different seasons for at least 2 years. The ‘Cerrado’ region, where most animal production takes place in Brazil, has 2 well defined seasons: spring-summer with warm weather and rain; and autumn-winter with cooler, dry weather. Thus, owing to environmental variation, especially related to climate, it is important to investigate the main effects of environmental factors (years and seasons), as well as interactions between genotypes and environmental factors in order to have greater confidence in the selection of superior hybrids of B. humidicola on the basis of agronomic and nutritional traits

Breeding Strategies for \u3cem\u3eBrachiaria\u3c/em\u3e spp. to Improve Productivity–An Ongoing Project

Two strategies have been used in the breeding of Brachiaria (syn. Urochloa) to produce new cultivars. The first involves exploring the natural variability existing in nature, which is the selection of ecotypes, mostly apomicts, from the diversity in germplasm banks. This strategy proved efficient originally and the cultivars in use in Brazil were derived in this way, but progress with this strategy is limited in the medium to long term

Physical Activity Counseling for Adults with Hypertension: A Randomized Controlled Pilot Trial

The effect of physical activity counseling (PAC) in hypertensive adults is unclear. This study investigated the effect of PAC on blood pressure (BP), physical activity level, sitting time, metabolic profile, and body composition in hypertensive adults. Twenty-two hypertensive adults (48.8 ± 7.3 years) participated in this pilot trial. The 12-week PAC was based on the 5 A’s model considering the FITT principle (Frequency, Intensity, Time, and Type) of physical activity. The control group received instructions about FITT in one face-to-face meeting at baseline. Pedometer-measured physical activity, sitting time, resting and ambulatory BP, metabolic profile (cholesterol, triglycerides, fasting glucose), and body composition (fat mass, abdominal fat, fat free mass) were assessed. The PAC group showed higher steps per day (5839 ± 992 vs. 5028 ± 902; p = 0.044) and a trend for lower sitting time (5.6 ± 1.3 vs. 8.0 ± 4.0 h/day; p = 0.059) than the control group. No changes were observed in BP, metabolic profile, and body composition (p > 0.05). In conclusion, 12 weeks of a PAC program based on the 5 A’s model resulted in a modest increase of ~800 steps per day and a trend to decrease ~2 h/day in sitting time, but there were no associated reduction in BP and improvements in metabolic and body composition