Genetic diversity of sweet potatoes collection from Northeastern Brazil

The sweet potato, Ipomoea batatas (L.) Lam has its origin in Tropical America. In Sergipe State (Brazil), its production is very important, and to explore its potential in local agriculture in the State, the Embrapa Coastal Tableland created a collection with 52 accessions located in Umbaúba City. Some accessions were from germplasm belonging to Embrapa vegetables and others from local farmers of Sergipe. Here, we provide the first data on the genetic diversity and structure of sweet potato collection of SPGB using random amplified polymorphic DNA (RAPD) markers. RAPD data were used to determine genetic variability via a model-based Bayesian procedure (structure) and molecular variance analysis (AMOVA). In addition, Shannon index, genetic diversity and Jaccard coefficients were also estimated. RAPD was efficient for the analysis of genetic diversity to identify groups and measure the genetic distance between accessions. The markers showed that the collection had a high level of polymorphism. By UPGMA, we separated three groups of genotypes and identified two reconstructed populations by structure software. Keywords: Ipomoea batatas, cultivars, accessionsAfrican Journal of Biotechnology, Vol. 13(10), pp. 1109-1116, 5 March, 201

Produtividade e principais problemas fitossanitários de cultivares de batata em Sergipe Yield and phytosanitary problems of potato cultivars in Sergipe, Brazil

Sete cultivares de batata (Solanum tuberosum L.) foram avaliadas durante três anos em Itabaiana-SE, com o objetivo de verificar a potencialidade de produção à altitude de 180 m e identificar os problemas fitossanitários que afetam a produtividade. Os experimentos foram conduzidos nos meses de junho a setembro, utilizando-se o delineamento experimental de blocos ao acaso, com cinco repetições. Após a colheita foram avaliadas a produção total, comercial (tubérculos sadios e com peso mínimo de 40 g) e perdas de produção decorrentes de sarna, podridão-mole, nematóide e insetos do solo. A análise conjunta das produções totais e comerciais de tubérculos revelou que as cultivares mais produtivas foram Baronesa (33,7 t/ha), Monalisa (32,7 t/ha) e Elvira (31,4 t/ha). A produção comercial variou de 3,4 t/ha a 22,5 t/ha, destacando-se as cvs. Elvira e Monalisa, com rendimentos de 22,5 t/ha e 20,5 t/ha respectivamente, com apenas três pulverizações com defensivos. Os problemas fitossanitários que mais afetaram a cv. Elvira foram sarna (13,1%) e nematóide das galhas (7,2%), enquanto a 'Monalisa' teve sua produção prejudicada mais pela incidência de insetos (15,1%), sarna (12,0%) e nematóide (9,7%). A cv. Monalisa apresentou tubérculos com melhores características para comercialização e está sendo cultivada a nível comercial em substituição às variedades Bintje e Baraka anteriormente cultivadas na região. Os resultados indicam a potencialidade da região de Itabaiana para a produção de batata.<br>The yield potential and main diseases affecting productivity of seven potato (Solanum tuberosum L.) cvs. were evaluated during a three years period in experiments carried out at low altitude conditions of Sergipe State, Brazil. The experimental plots were located at 180 m of sea level in a Red-Yellow Podzolic sandy-clay texture soil. The experimental design was of complete randomized blocks with five replications. Tubers were sown yearly in June and harvested in September. After harvest, total yield, commercial yield (healthy tubers with 40 g minimum weight) and losses caused by scab, soft-rot, nematodes, and soil insects were evaluated. The analysis of variance for total and commercial yield of tubers highlighted Baronesa (33.7 kg/ha), Monalisa (32.7 kg/ha), and Elvira (31.4 kg/ha) as the most productive cvs. The commercial yields varied from 3.4 t/ha to 22.a t/ha. The cvs. Elvira and Monalisa, yielded 22.5 kg/ha and 20.5 kg/ha, respectively. Only three insecticides applications were necessary. Scab (13.1%) and nematode (7.2%) were the main phytosanitary problems affecting Elvira cv. In relation to Monalisa, pin larvae soil insect (15.1%), scab (12.0%), and nematode (9.7%) were the main causes of yield loss. Because of its best commercial tuber characteristics Monalisa has been planted instead of Bintje and Baraka, both commonly used in the region. The results indicate the suitability of Itabaiana region for potato production