Morphoagronomic characterization of sweet potato accessions from the germplasm bank of Embrapa hortaliças / Caracterização morfológica de acessos de batata-doce mantidos no banco de germoplasma da Embrapa Hortaliças

Studies on the determination of genetic divergence among genotypes are important tools in breeding programs, contributing to the identification of parents with considerable productive potential. However, little is known about the combinatorial capacity of sweet potato (Ipomoea batatas) accessions and its adaptation to the different regions of Brazil. The objective of this study was to evaluate the morpho-agronomic traits from 102 sweet potato accessions from the Germplasm Bank of Embrapa Hortaliças. The experiment was laid out as an augmented block design comprised of 102 treatments. Nineteen above ground traits were measured using descriptors for the respective parts. Estimated values of broad sense heritability were high for the traits mean branch length (95.75%), immature leaf color (85.06%), and predominant branch color (90.57%). Coefficients of environmental variation were below 30.00% for all variables, except for branch weight (51.62%). The 102 clones analyzed presented broad genetic variability for the different traits evaluated, especially for branch weight, and branch length, and mature leaf color.

Estudos de determinação de divergência genética entre genótipos são ferramentas de grande importância em programas de melhoramento, auxiliando na identificação de genitores com considerável potencial produtivo. No entanto, pouco ainda se sabe sobre a capacidade combinatória de acessos de batata-doce (Ipomoea batatas) e sobre a adaptação a diferentes regiões do Brasil. O objetivo deste trabalho foi avaliar características agronômicas de 102 acessos de batata-doce mantidos no Banco de Germoplasma da Embrapa Hortaliças. O experimento foi instalado utilizando o delineamento em blocos aumentados, com 102 tratamentos. Foram mensuradas 19 características da parte aérea utilizando-se descritores das respectivas partes. Os valores das estimativas de herdabilidade no sentido amplo foram altos para as características comprimento médio das ramas (95,75%), cor da folha imatura (85,06%) e cor predominante da rama (90,57%). Os coeficientes de variação foram inferiores a 30 % para todas as variáveis, exceto para peso das ramas (51.62%). Os 102 clones analisados apresentaram ampla variabilidade genética para as diferentes características avaliadas, principalmente para peso das ramas, comprimento das ramas e cor da folha madura

Field adaptation of sweet potato genotypes enriched of ß - carotene, in the state of Goiás / Adaptação no campo de genótipos de batata-doce enriquecidos de ß-caroteno, no estado de Goiás

Most sweet potato genotypes marketed in Brazil have white, yellow or cream pulp color with negligible carotenoid contents. The use of beta-carotene rich sweet potato materials may contribute to improve people welfare, especially those at critical nutritional conditions. The yield-related traits and marketable tuber quality of 10 beta-carotene biofortified (or not) sweet potato genotypes were assessed in a Brazilian Cerrado area. Differences for all traits were found, with some materials prevailing. However, four of them (CNPH 1190, CNPH 1206, CNPH 1210 and CNPH 1310) showed good adaptability. CNPH 1210 had the highest yield (52.21 ton ha-1), 4.28 times higher than the Brazilian sweet potato average yield. CNPH 1210 and CNPH 1310 had the highest tuber numbers and the most preferred mass class for consumers, and therefore, they furnished the best marketable genotypes. Nevertheless, the materials CNPH 1210 and CNPH 1310 (both orange-fleshed sweet potatoes) stood out for tuber market quality. Our results may stimulate organized civil society efforts to improve the production and consumption of beta-carotene-rich sweet potato materials in municipalities in the Brazilian Cerrado.

A maioria dos genótipos de batata-doce comercializados no Brasil tem cor de polpa branca, amarela ou creme, com conteúdo desprezível de carotenóides. O uso de materiais de batata-doce ricos em beta-caroteno pode contribuir para melhorar o bem-estar das pessoas, especialmente aquelas em condições nutricionais críticas. Características relacionadas ao rendimento e a qualidade comercial dos tubérculos de 10 genótipos de batata-doce biofortificada (ou não) com beta-caroteno foram avaliadas em uma área do Cerrado brasileiro. Diferenças para todas as características foram encontradas, com alguns materiais predominantes. No entanto, quatro deles (CNPH 1190, CNPH 1206, CNPH 1210 e CNPH 1310) mostraram boa adaptabilidade. O CNPH 1210 teve o maior rendimento (52,21 ton ha-1), 4,28 vezes maior que o rendimento nacional médio da batata-doce brasileira. CNPH 1210 e CNPH 1310 tiveram o maior número de tubérculos e a classe de massamais preferida para os consumidores e, portanto, forneceram os melhores genótipos comercializáveis. Noentanto, os materiais CNPH 1210 e CNPH 1310 (ambos batata-doce de polpa alaranjada) destacaram-se pelaqualidade dos tubérculos comerciais. Nossos resultados podem estimular esforços da sociedade civil organizada para melhorar a produção e consumo de materiais de batata-doce ricos em beta-caroteno em municípios contidos no Cerrado brasileiro.

Phenotypic recurrent selection in the common bean (Phaseolus vulgaris L) with carioca-type grains for resistance to the fungi Phaeoisariopsis griseola

The efficiency of recurrent selection was assessed in obtaining common bean (Phaseolus vulgaris L) plant lines resistant to the phytopathogenic fungi Phaeoisariopsis griseola. The base bean population was obtained from the partial diallel between seven lines with carioca-type grains and 10 sources of resistance to P. griseola. The plants most resistant to the pathogen were selected in the F2 (S0) generation of the populations (C-0). The best S0:1 plants that presented carioca-type grains were intercrossed to obtain cycle I (C-I). The same procedure was adopted to obtain cycles C-II to C-V. In each recurrent selection cycle, S0:1 progenies selected were also assessed in experiments carried out in Lavras, Brazil, always using as check the Carioca MG (susceptible to P. griseola) and Pérola (tolerant) cultivars. The response to selection for resistance to the pathogen was estimated from the general mean of the S0:1 progenies from each selective cycle compared to the susceptible check Carioca MG. The estimated gain was 6.4 percent per cycle and the indirect response in grain yield by selection for resistance to the pathogen was 8.9 percent per cycle. The variability detected among the progenies in the last selective cycles enabled the prediction of additional responses to recurrent selection.