Alfredo do Nascimento Junior

Yield and nutritive value of dual purpose winter cereals: green forage, silage or grain.

This study was carried out to evaluate 14 genotypes of six winter species for yield and nutritive value of early forage and silage or regrowth grain. The experiment was in a randomized complete block design with three replications, so that the plots consisted of seven 5.0 m-long rows spaced at 0.2 m. The seeding date was April in the three study years and fertilization followed the recommendations for the crops. During the tillering period and after cutting, urea was applied at the rate of 22.5 kg N/ha. Each plot was cut at a height of 7.0 cm from the soil to estimate the forage yield per genotype, when plants reached 30 cm height. Half the regrowth of each plot was used for silage and half for grain. Harvesting for silage was at the dough stage, from 30 to 35% DM. Nutritive value analyses were made using the near infrared spectroscopy (NIRS) technique. Rye BRS Serrano was superior for green forage, silage, and total forage yield (green forage + silage) and regrowth grain yield. However, for grain yield, BRS Serrano rye was similar to BRS 277 wheat, BRS 148 and BRS 203 triticales, UPF 18 oats, and BR 1 rye. It is possible to obtain early forage using genotypes of rye, wheat, barley, and triticale, producing equivalent forage yields to those obtained with black oats pasture. Embrapa 53 triticale and UPF 18 oats yielded more digestible green forage, but the silages had digestibility similar to barley silage.

Viabilidade polínica como seleção assistida no programa de melhoramento genético de triticale

The objective of this study was to analyze the pollen grain viability of 52 triticale genotypes from the 2005 crossing block of the Embrapa Wheat breeding program. The spikes were collected prior to anthesis and cytological analyses were performed upon fixing the anthers from the basal, medium, and apical regions of the spike and replicated three times for each sample. For each slide, about 200 pollen grains were analyzed and they were classified into two different groups: 1) normal or viable and 2) non-viable or abnormal. The obtained data were analyzed and the means were compared by the Duncan test at 5% propability. The results of analysis of variance demonstrated that the differences among the genotypes were highly significant. However, most of the genotypes studied showed a high percentage of normal pollens. Cytological analysis of the pollen grain is potentially useful as assisted selection in a breeding program, especially to decrease the possibility of obtaining sterile plants or plants with less grain production.

Genetic diversity of Brazilian triticales evaluated with genomic wheat microsatellites

The objective of this work was to determine the genetic variability available for triticale (X Triticosecale Wittmack) crop improvement in Brazil. Forty-two wheat genomic microsatellites were used to estimate the molecular diversity of 54 genotypes, which constitute the base of one of the major triticale breeding programs in the country. Average heterozygosity was 0.06 and average and effective number of alleles per locus were 2.13 and 1.61, respectively, with average allelic frequency of 0.34. The set of genomic wheat microsatellites used clustered the genotypes into seven groups, even when the germplasm was originated primarily from only two triticale breeding programs, a fact reflected on the average polymorphic information content value estimated for the germplasm (0.36). The 71.42% transferability achieved for the tested microsatellites indicates the possibility of exploiting these transferable markers in further triticale genetic and breeding studies, even those mapped on the D genome of wheat, when analyzing hexaploid triticales.

BRS 374 - wheat cultivar

BRS 374 is a wheat cultivar developed by Embrapa. It resulted from a cross between the F1 generation of PF 88618/Coker80.33 and Frontana/Karl. BRS 374 belongs to the soft wheat class, has a low plant height, a high potential grain yield, and white flour.

Estimation of Blast Severity on Rye and Triticale Spikes by Digital Image Analysis

In Brazil, more efficient methods are a necessity for evaluating blast severity on spikes in the breeding programs of rye, triticale, wheat, and barley. The objective of this work was to determine the feasibility of assessing blast severity based on the analysis of digital images of symptomatic rye and triticale spikes. Triticale and rye genotypes were grown to anthesis in pots and were then inoculated with a mixture of Magnaporthe oryzae isolates. Blast severity on the spikes was evaluated visually and after that the spikes were detached and photographed. Blast severity was determined using the program ImageJ to analyze the obtained images. Two methods of image analysis were used: selection of symptomatic areas using a mouse cursor (SCU) and selection of symptomatic areas using image segmentation (SIS). The SCU method was considered the standard reference method for determining the true value of blast severity on spikes. An analysis of variance did not determine any difference among the evaluation methods. The coefficient of determination (R2) obtained from a linear regression analysis between the variables SIS and SCU was 0.615. The obtained data indicate that the evaluation of blast severity on spikes based on image segmentation is feasible and reliable.

BRS Saturno triticale cultivar

The triticale cultivar BRS Saturno was developed by Embrapa (Brazilian Agricultural Research Corporation) in partnership with the Fundacao Pro-Sementes de Apoio a Pesquisa. It is the result of a cross between the genotypes PFT 512 and CEP 28 Guara, adapted to the environmental conditions of cultivation in southern Brazil.

Estabilidade genética em triticale estimada pela viabilidade polínica

The study aimed to infer about the genetic stability from the pollen viability in hexaploid triticale genotypes used in block crossings breeding program from Brazilian Company of Agriculture Research (Embrapa Wheat). The experiments were conducted in a randomized design. For each genotype five repetitions were assessed. Each replication consisted of one plant and each replication consisted of one plant. Two hundred pollen grains were analyzed by optical microscopy and by the squash technique with 1% acetic carmine dye per slide, totalizing 1,000 pollen grains per genotype. The variables analyzed were: binucleate and trinucleate pollen grains, with little starch, empty, with more than one pore and with different sizes. The data were submitted to analysis of variance and compared by Tukey test at 1%. There were significant differences between all variables. The percentage of binucleate and/or trinucleate grains ranged from 74 to 97%. We conclude that 66% of genotypes present pollen viability above 90% and they are indicated to remain of the breeding program of triticale, both in the selection of parenting as during the crossing and backcrossing. Therefore, the cytogenetic studies represent excellent support tool for breeder in selecting the most stable genotypes.

Resultados agronômicos e qualitativos da nova cultivar de trigo 'BRS 296'

The wheat cultivar BRS 296, developed by Embrapa, was released to production in 2009. It was originated of cross between PF 93232 and COOK*4/VPM1, carried out in green-house, in the summer of 1992/1993. The segregate generations were conducted by genealogic method until homozigose of genotype, named PF 990283. It has excellent leave and spike sanity and production stability. Preliminarily, it was classified as Bread Wheat and is recommended to all wheat regions of Brazil.

BRS Louro: wheat cultivar

Wheat cultivar ‘BRS Louro’ was developed by Embrapa (Brazilian Agricultural Research Corporation). It was result of a cross of PF 869114 and BR 23. ‘BRS Louro’ has excellent agronomic features, medium resistance to scab and high grain productivity.

AGENTES MUTAGÊNICOS E A INTENSIDADE DE VARIABILIDADE GENÉTICA NO CARÁTER ESTATURA DE PLANTAS DE AVEIA (AVENA SATIVA L.)

SUMMARY Genetic variability is basic for oat progress in southern Brazil. Adaptative trait, as plant stature, could be of major importance for oat crop development. In this way, mutation breeding should be an efficient tool for plant breeders develop new genetic combinations for selection of superior genotypes. Two mutagenic agents, sodium azide and γ-ray, were applied on two oat varieties, UFRGS-7 and UFRGS-8, using different product doses. In order to induce heritable alterations (micromutations), the sodium azide showed the best beneficts, withoutshowing deleterious effects on plants. The data obtained evidenciated that mutation breeding is an interesting approach in order to enlarge oat variability range in southern Brazil.