Efeito Da Aplicação De Fungicidas No Controle De Doenças Foliares De Arroz Irrigado E Sua Relação Com O Rendimento Industrial

Leaf diseases of rice can compromise grain filling and spikelet maturation for accelerating the drying of grains and, consequently, reducing the industrial yield. The use of fungicide has the potential to reduce the damage from leaf diseases and increase the industrial yield. The aim of this study was to evaluate the number of fungicide application at different growth stages on the control of leaf diseases for multiple pathosystem (blast, brown spot and scald) and its relationship with the industrial yield (income benefit, whole and broken grains). The experiments were conducted in the growing seasons 2011/12 and 2012/13 in Rio do Oeste County, located at Alto Vale do Itajaí, Santa Catarina State. Rice cultivar SCS 116 Satoru was used. Experimental design was in randomized blocks with four replicates and six treatments constituted of applications of a mixture of fungicides difenoconazole and azoxystrobin, while one of the treatments (control) received no chemical application. Fungicide applications were performed at V8 vegetative stage and at the reproductive stages R0, R2, R4 and R6. Harvest was manually performed, obtaining 2m2 of the central area of each plot. One, two, three, four and five fungicide applications showed an average increase, compared to the control, in the two seasons, of 6%, 7.2%, 13.1%, 17.4% and 19.2% of the income benefit, 14.6%, 28.5%, 36.1%, 45% and 48.7% for whole grains, while the percentage of broken grains reduced by 4.4%, 13.2%, 21.7%, 35% and 41.4%, respectively. © 2016, Universidade Estadual Paulista (UNESP). All Rights Reserved.421858

Utilização de microssatélites e RAPD na caracterização molecular de acessos de paspalum urvillei steudel

Este estudo foi realizado com o objetivo de verificar a diversidade genética na coleção de acessos de P. urvillei do Departamento de Plantas Forrageiras e Agrometeorologia(DPFA) da Faculdade de Agronomia (UFRG) visando sua utilização em futuros trabalhos de seleção. Foram avaliados 64 acessos provenientes do Rio Grande do Sul, 1 de Xanxerê, Santa Catarina, três de Curitiba, Paraná, e 1 da Argentina. A diversidade genética foi analisada por meio de marcadores do tipo RAPD e SSR. Utilizaram-se dez primers para marcadores RAPD, o que possibilitou obter 56 bandas polimórficas e 11 grupos no dendrograma com similaridade média de 0,70. Na técnica de SSR, foram utilizados sete primers e obtidas 28 bandas polimórficas, formando sete grupos no dendrograma com similaridade média de 0,66. Ambos os marcadores foram eficientes para o agrupamento de acessos coletados. O uso de maior número de primers para gerar mais bandas polimórficas foi necessário para obtenção de fingerprints genômicos dos indivíduos similares. Os dendrogramas gerados neste estudo dão subsídios para futuros cruzamentos de gerações parentais contrastantes ou similares no melhoramento de Paspalum urvillei.The aim of this study was to estimate the genetic diversity among accesses of P. urvillei of Departamento de Plantas Forrageiras e Agrometeorologia (DPFA) of the College of Agronomy – UFRGS and to evaluate their use in selection programs. Sixty four accesses from different cities of the Southern Region of Brazil (Rio Grande do Sul, Santa Catarina and Parana States) and from Argentine were analyzed by RAPD and SSR molecular markers. Ten primers of RAPD markers were used and resulted in 56 polymorphic bands and 11 groups in a dendrogram with average similarity 0.70. Seven primers were used for the SSR technique and resulted in 28 polymorphic bands and seven groups in a dendrogram with average similarity 0.66. Both markers were efficient on grouping the accesses collected across the Southern region. A large number of primers was required to generate additional polymorphic bands to get genomic fingerprints of similar individuals. The dendrograms obtained from this study provided significant information for designing crossing strategies of parental generations in breeding programs of P. urvillei