Centauro – oat cultivar for ground cover and grazing

Plants and seeds of oat cultivar BRS Centauro, of the species Avena brevis Roth., are highly uniform. The crop cycle is long, the suitability as fodder excellent, and leaf production particularly high, resulting in better quality forage than that of the black oat forage controls.


INTRODUCTION
The food base of the Brazilian meat and milk production is forage, supplied in the form of silage or hay, or directly on planted or natural pastures, which are highly dependent on seasonality and weather.In certain periods, i.e., the dry season, the food supply by pastures is insufficient to meet the animals' needs, which could be circumvented by supplementing grains in high-cost diets, hay or silage (Meinerz et al. 2012).
Oat is one of the main winter crops in southern Brazil.There are no official statistics in relation to the area used for black oat (Avena strigosa Schreb.), the species most commonly planted for soil cover as well as incrop-livestock systems.However, most genotypes available are still common oat populations with high genetic variability, without proven genetic origin, used on large-scale farms, because the amount of seed of registered cultivars is insufficient to meet market demands.
In the states of Rio Grande do Sul, in Santa Catarina and Paraná, in the 2012/13 growing season, grain was harvested on 18.33 million hectares.Of this total, 4.46 million hectares were used for maize and 9.83 million for soybean, totaling 14.29 million hectares of cultivation in the summer or second growing season.However, of this area occupied in the summer, only 2.26 million hectares were used in the winter for grain crops IBGE (2013).Large areas are available for pasture for meat and milk production, where winter forages could be planted, combining the opportunity with the requirements of the farm enterprise.
According to Valentini et al. (2014), oat is one of the most important cereal crops in the world and the genus Avena L. includes wild and domesticated species with different levels of ploidy, with extensive genetic diversity among and within species.
Species of the genus Avena occur naturally in several parts of the world.These diploid species are part of a particular group with 14 (2n) chromosomes, including the species Avena strigosa Schreb.and Avena brevis Roth.(Tavares et al. 1993).According to these authors, citing Ladizinsky and Zohary (1971) and Ladizinsky (1989), the species A. strigosa, A. brevis, A. hirtula and A. wiestii belong to the biological species Avena strigosa.In the group with genome A, diploid, there are two sub-groups (Yabuno and Nishiyama 1975) with the genomes AsAs and tAtA (Tavares et al. 1993, Ladizinsky 2012).Both Avena strigosa and Avena brevis are in the AsAs subgroup.According to Leggett (1992), the species Avena strigosa, Avena brevis, Avena hispanica and Avena nuda, are part of the same section called Agraria; the first three are similar and the botanical identification resulted in the same taxonomic classification, differing from Avena hispanica only in the lodicules.Hybrids of crosses between Avena strigosa and Avena brevis were fertile, indicating close proximity between these species, including morphologically.Applied Biotechnology 15: 117-119, 2015 A Nascimento Junior et al.

Crop Breeding and
Owing to the importance of planting oats for the maintenance of a mulch cover in the no-tillage system and the sustainability of dairy and beef cattle ranching, Embrapa Wheat resumed research on oats after the introduction of several genotypes in 1996 and oat cultivar BRS Centauro was developed as a result of this endeavor, as an alternative to the common oat populations, still sold in Brazil.

BREEDING METHOD
The main breeding method was modified mass selection.A line named accession IPFA 99012 was derived from a population originally from Portugal, maintained in a collection of the Agricultural Research Service (ARS), of the US Department of Agriculture, with the synonyms "TURGIDA" and "CLAV 4749".
In 1996, 84 oat populations from various sources were introduced from ARS, and sown in the field in 1997, of which the 39 populations with best growth and development were harvested in bulk.In the following year, the 39 populations were resown, and modified mass selection cycles were performed during plant growth, with negative selection, in each population.In 1999, the populations were given experimental designations from IPFA 99001 to IPFA 99039 and adaptation tests were performed to evaluate plant traits, testing mainly forage suitability.Roguing was applied in 2000, 2003 and 2004, to

PERFORMANCE ASSESSMENT
The yield performance of line IPFA 99012 was evaluated in 2007, 2009 and 2010 in VCU tests in Coxilha, Passo Fundo and Vacaria in Rio Grande do Sul and São José do Cedro in the State of Santa Catarina.The control cultivars UPFA 21 -Moreninha and Agro Zebu, both Avena strigosa, were used for comparison.The experiments were conducted in a randomized block design, without fungicide treatment and without supplemental irrigation.The plots consisted of eight 5 m long rows, spaced 0.2 m apart, of which the four center rows, disregarding 0.5 m at either end, were evaluated, in three replications.To evaluate forage, three cuts were performed, either by hand or with a forage harvester, maintaining a plant height of about 7 cm above the soil surface.After each harvest, 30 kg ha -1 of N was applied in the form of urea, proportionately in each plot.An exception was made for the experiment in Vacaria in 2009, in which the plants were cut only once, between the stages of soft and hard grain mass, to evaluate the dry matter production for silage.In the analysis, the effects of cultivars were considered fixed and other effects random.
Line IPFA 99012 exceeded the control mean by 6.7% Crop Breeding and Applied Biotechnology 15: 117-119, 2015 in fresh and dry matter production (kg ha -1 ), in the overall average (Table 1).In the treatments with three cuts, dry matter production was on average 5,394 kg ha -1 , versus a control mean of 5,426 kg ha -1 .However, in 2009, in Vacaria, the potential of line IPFA 99012 was evidenced by a dry matter production for silage of 15,713 kg ha -1 versus a control mean of 11,734 kg ha -1 (Table 1).
Line IPFA 99012 was market-approved as BRS Centauro for forage production, ground cover and for grain/ seed production in all wheat-growing regions in the South and central South of Brazil, in the states of Rio Grande do Sul, Santa Catarina, Paraná, Mato Grosso do Sul and São Paulo, in winter cultivation.

OTHER FEATURES
BRS Centauro has excellent mean leaf:stem ratio in relation to the stem (3.4 times higher), while for the control, this ratio was at most 2.5 times higher.The percentage of covered soil area in the first cut was on average 85%, with excellent regrowth capacity after the cuts.
The oat cultivar BRS Centauro is susceptible to stem rust, leaf rust, barley yellow dwarf virus (BYDV) and powdery mildew; it is tolerant to soil acidity.BRS Centauro is released as an additional option for inclusion in cropping systems for ground cover and animal foraging, to replace the common oat populations in the market.
According to the International Union for the Protection of New Varieties of Plants (UPOV), BRS Centauro is the first protected Avena brevis Roth.cultivar in the world.BRS Centauro differs from the original population "TURGIDA" in the following characteristics: growth habit, cycle (from emergence to the first visible spikelet in at least 50% of the panicles) and uniformity of inflorescence (data not shown).

SEED MAINTENANCE AND DISTRIBUTION
The oat cultivar BRS Centauro is registered and protected by the Ministry of Agriculture, Livestock and Supply (MAPA) of Brazil since 10/05/2012 under the number 29179 and protection certificate from 04/01/2013, under number 20130220.Embrapa Wheat produces the genetic seed of the cultivar, Embrapa Products and Markets the basic seed, and the founders of the South Brazilian association for the promotion of forage research (Sulpasto), in partnership with Embrapa, are solely responsible for the production of certified seed.
improve the uniformity of the population, maintaining the denominations.In view of the agronomic traits and plant uniformity, the populations IPFA 99001, IPFA 99004, IPFA 99009, IPFA 99012, and IPFA 99013, were evaluated in tests of Value of Cultivation and Use (VCU) for forage yield between 2007 and 2010.Distinctness, uniformity and stability (DUS) were tested in 2009 and 2010.Due to the superior results obtained in the VCU tests and purity in seed multiplication, line IPFA 99012 was registered in the National Register of Cultivars (RNC) and protected by the National Plant Variety Protection Service (SNPC).