Análises bioquímicas e isoenzímicas de variedades de capim elefante Pennisetum purpureum (Schum)

This study characterized seven Pennisetum purpureum varieties, namely v. Anão, Bajra, Cameroon, Guaçu, Roxo, Taiwan A-144 and Uruckwami, through biochemical analyses, including protein, glucose and fructose contents, and polyacrylamide gel electrophoresis using the esterase system, by sampling 30, 60, 90, 120 and 150 day-old leaves. The number of nodes per stem and the percentage of bud emergence were also recorded. Variety Taiwan A-144 presented the highest number of nodes per stem and percentage of emerging buds. Protein concentration decreased gradually after 60 days for all varieties, except for Anão. Variety Guaçu presented the highest level of glucose in 90 day-old plants, whereas Cameroon presented the highest levels at 120 and 150 days. The esterase band patterns changed with plant age for all varieties, showing a tendency to increase the number of bands with time. The best age for discriminating between esterase bands of P. purpureum varieties was at 120 days, when most variation could be observed.Foram analisadas sete variedades de P. purpureum, tais como: Anão, Bajra, Cameroon, Guaçu, Roxo, Taiwan A-144 e Uruckwami, através de testes bioquímicos determinando a concentração de proteínas, glicose e frutose, além de observar, através de gel de eletroforese, as bandas de esterase. Os extratos protéicos foram preparados amostrando-se folhas com 30, 60, 90, 120 e 150 dias. Os números de nós por colmo e a porcentagem de brotamento das gemas foram também avaliados. A variedade Taiwan A-144 apresentou o maior número de nós por colmo e porcentagem de brotamento das gemas. Com relação à concentração de proteínas, esta decresceu gradualmente após 60 dias para todas as variedades, com exceção da Anão. A maior concentração de glicose foi apresentada pela variedade Guaçu aos 90 dias e pela Cameroon aos 120 e 150 dias. Os padrões eletroforéticos da esterase se alteraram com a idade da planta para todas as variedades, mostrando tendência a aumentar o número de bandas com o tempo. A melhor idade para discriminar as variedades de capim elefante foi aos 120 dias, onde foi encontrada maior variação

Genetic diversity among air yam (dioscorea bulbifera) varieties based on single sequence repeat markers

Dioscorea is the largest genus in the Dioscoreaceae family, and includes a number of economically important species including the air yam, D. bulbifera L. This study aimed to develop new single sequence repeat primers and characterize the genetic diversity of local varieties that originated in several municipalities of Brazil. We developed an enriched genomic library for D. bulbifera resulting in seven primers, six of which were polymorphic, and added four polymorphic loci developed for other Dioscorea species. This resulted in 10 polymorphic primers to evaluate 42 air yam accessions. Thirty-three alleles (bands) were found, with an average of 3.3 alleles per locus. The discrimination power ranged from 0.113 to 0.834, with an average of 0.595. Both principal coordinate and cluster analyses (using the Jaccard Index) failed to clearly separate the accessions according to their origins. However, the 13 accessions from Conceição dos Ouros, Minas Gerais State were clustered above zero on the principal coordinate 2 axis, and were also clustered into one subgroup in the cluster analysis. Accessions from Ubatuba, São Paulo State were clustered below zero on the same principal coordinate 2 axis, except for one accession, although they were scattered in several subgroups in the cluster analysis. Therefore, we found little spatial structure in the accessions, although those from Conceição dos Ouros and Ubatuba exhibited some spatial structure, and that there is a considerable level of genetic diversity in D. bulbifera maintained by traditional farmers in Brazil152CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão tem2007/04805-

Genetic characterization of cassava (Manihot esculenta) landraces in Brazil assessed with simple sequence repeats

Based on nine microsatellite loci, the aim of this study was to appraise the genetic diversity of 42 cassava (Manihot esculenta) landraces from selected regions in Brazil, and examine how this variety is distributed according to origin in several municipalities in the states of Minas Gerais, São Paulo, Mato Grosso do Sul, Amazonas and Mato Grosso. High diversity values were found among the five above-mentioned regions, with 3.3 alleles per locus on an average, a high percentage of polymorphic loci varying from 88.8% to 100%, an average of 0.265 for observed heterozygosity and 0.570 for gene diversity. Most genetic diversity was concentrated within the regions themselves (HS = 0.52). Cluster analysis and principal component based scatter plotting showed greater similarity among landraces from São Paulo, Mato Grosso do Sul and Amazonas, whereas those from Minas Gerais were clustered into a sub-group within this group. The plants from Mato Grosso, mostly collected in the municipality of General Carneiro, provided the highest differentiation. The migration of human populations is one among the possible reasons for this closer resemblance or greater disparity among plants from the various regions

PERFORMANCE OF YIELD AND YIELD CONTRIBUTING CHARACTERISTICS OF BC2F3 POPULATION WITH ADDITION OF BLAST RESISTANT GENE

ABSTRACTThe study was carried out in the University Putra Malaysia (UPM) Rice Research Centre to evaluate the yield performance of newly developed selected blast resistant plants of BC2F3 generations derived from a cross between MR263, a high yielding rice variety but blast susceptible and Pongsu Seribu 1, donor with blast resistant (Pi-7(t)and Pi-d (t)1, Pir2-3(t)genes and qLN2 QTL), Malaysian local variety. On the basis of assessed traits, the plants 12, 6, 7, 5, 21, 22, 5, 26, 11, 8, 10, 13 and 15 had the higher yield, blast resistant and good morphological traits. More than 70% heritability was found in days to maturity, plant height, tiller numbers per hill, and panicle per hill, 80% heritability was found in filled grain and yield per hill and more than 90% heritability was found in grain length, grain width and seed weight. Cluster analysis based on the traits grouped 30 plants along with MR263 into seven clusters. According to PCA, the first four principal components account for about 69.3% total variation for all measured traits and exhibited high correlation among the characteristics analyzed