Realce : Common bean cultivar with striped grains for the state of Minas Gerais

The common bean cultivar “BRSMG Realce”, recommended for the state of Minas Gerais, has high yield potential and resistance to powdery mildew, bacterial wilt and to anthracnose pathotypes 65, 73, 77, 81, 91, 475 and 479. The plants and pods are high, resulting in lower loss during mechanical harvest.


INTRODUCTION
In most regions of the state of Minas Gerais, consumer preference is for "carioca" type common beans (beige with brown stripes) (Ramalho and Abreu 2006).In some specific regions, such as the Zona da Mata region of Minas Gerais, the preference is for black and also red beans.However, throughout the state, other types of beans, which may be considered as special varieties, like the striped type, even though less consumed, attain higher prices in the market.Therefore, for the producer, production of this type of bean has advantages, which may contribute to increased income.
One of the few bean cultivars with this type of seed now available on the market is BRS Radiante (Faria et al. 2003).Therefore, the institutions that work with genetic breeding of common bean in Minas Gerais, the Federal Universities of Lavras (UFLA) and of Viçosa (UFV), the Crop and Livestock Research Company of Minas Gerais (Empresa de Pesquisa Agropecuária de Minas Gerais -Epamig) and the Brazilian Crop and Livestock Research Company (Empresa Brasileira de Pesquisa Agropecuária -Embrapa), have made a joint effort in evaluation of inbred lines with this type of bean, for the purpose of obtaining and recommending new options of striped bean cultivars superior to BRS Radiante for producers.As fruit of this joint work, "BRSMG Realce" is recommended, a new option of a striped common bean cultivar for the state of Minas Gerais.

BREEDING METHODS
The BRSMG Realce cultivar arose from the PR 95105259/PR 93201472 cross, made in 1996 at Embrapa Arroz e Feijão.In 1997, the F 2 population was grown in a screen house in Santo Antônio de Goiás.In 1998, in the F 3 generation, selection of individual plants was made in regard to angular leaf spot, rust and anthracnose.The F 3:4 progenies obtained were advanced in bulk without selection.In 1999, a new selection of individual plants within the F 3:5 families was made for resistance to anthracnose, angular leaf spot and upright plant architecture.Also in 1999, in the F 5:6 generation, a selection of lines for upright plant architecture and high bean yield was made.In the LC Melo et al.The experiments were conducted by UFLA, UFV, Embrapa Arroz e Feijão and Epamig in the state of Minas Gerais in the environments shown in Table 1.A randomized block experimental design was used with three replications, with plots consisting of four four-meter rows.The BRSMG Realce cultivar has a type I determinate growth habit.In assessments of plant architecture and tolerance to lodging by means of a scoring scale, it exhibited performance similar to that of the "BRS Radiante" control (Table 2).However, since it has higher plants and pods in relation to the soil, it is more adapted to direct mechanical harvest, which leads to lower losses during this process when compared to BRS Radiante.

Reaction to diseases
During the assessments performed in the field, it showed moderate resistance to naturally occurring pathogens (powdery mildew, rust and angular leaf spot), with a degree of severity similar to that of the control BRS Radiante (Table 2).Its resistance to powdery mildew should be noted since this disease generally reduces the yield of cultivars with large seeds, as is the case of BRSMG Realce.It presented resistance to the anthracnose pathotypes 65, 73, 77, 81, 91, 475 and 479, in assessments performed by artificial inoculation in a greenhouse and in the field.It also showed resistance to bacterial wilt, as well as moderate resistance to common bacterial blight and fusarium wilt.

Crop cycle
Flowering of the BRSMG Realce cultivar occurs, on average, at 35 days.In assessments made in the state of Minas Gerais, the crop cycle was similar to that of BRS Radiante, with maturity, on average, at 83 days.

Yield
The BRSMG Realce cultivar had a mean seed yield greater than that of the controls in 16 of the 26 environments in which it was assessed (Table 1).It was also greater than that of the controls when considering the mean value of the locations in each crop season in the state and in the mean value of all the locations and crop seasons.Its yield in the winter crop season especially should be noted, which was 8% greater than the mean value of the controls.

Technological and industrial quality of the seed
The BRSMG Realce cultivar has striped seeds, similar to those of the BRS Radiante cultivar, with mean 100-seed weight of 35 g.It has excellent cooking qualities and cooking time comparable to most of the common bean cultivars which are currently recommended.

BASIC SEED PRODUCTION
The BRSMG Realce cultivar was registered in the name of Embrapa, Epamig, UFLA and UFV in the National Cultivar Registry (Registro Nacional de Cultivares -RNC) of the Food, Livestock and Agriculture Ministry (Ministério da Agricultura, Pecuária e Abastecimento -MAPA) on 10/03/2011 under number 28129 and protected in the National Cultivar Protection Service (Serviço Nacional de Proteção de Cultivares -SNPC) on 03/26/2012 (certificate no.20120069).Seed production of this cultivar is under the responsibility of Epamig.

F 5 :
7 generation in 2000, a new selection of lines was carried out for upright plant architecture, high yield, resistance to common bacterial blight, powdery mildew and anthracnose and commercial type of striped bean.The F 5:8 generation was assessed for yield and plant architecture, selecting the LM 200208821 line.In 2001, this line was assessed in the Preliminary Striped Seed Trial (EPL), together with 30 additional lines and two controls in two locations: Santo Antônio de Goiás, GO, in the winter season, and Ponta Grossa, PR, in the dry season.In 2003, it was assessed in the Intermediate Trial (EI) with ten additional lines and two controls in seven environments: Santo Antônio de Goiás, GO, in the winter season; Ponta Grossa, PR, in the rainy and dry season; Lavras, MG, in the dry season; Sete Lagoas, MG, in the dry season; Simão Dias, SE, in the rainy season; and Seropédica, RJ, in the winter season.The results obtained in joint analysis of grain yield and other agronomic characteristics allowed the LM 200208821 line, with the pre-commercial name of CNFRJ 10556, to be promoted to the Value for Cultivation and Use (VCU) field trial.As of the 2005 dry crop season up to the 2006/2007 rainy season, this line was assessed in the trials for determination of Value for Cultivation and Use (VCU), together with 21 other lines and the controls BRS Radiante and Jalo EEP 558.

Table 1 .
Mean seed yield (kg ha -1 ) of the BRSMG Realce cultivar and of the controls (BRS Radiante and Jalo EEP 558) by location, season and year of assessment in the state of Minas Gerais

Table 2 .
Some traits of the BRSMG Realce cultivar and of the BRS Radiante control obtained in the trials conducted in the state of Minas Gerais in 2005 and 2006 and in assessments under controlled conditions undertaken at Embrapa Arroz e Feijão in 2009