Evaluation of phenotypic stability of cassava clones by AMMI analysis in northwestern Paraná state

High yield stability and adaptability of storage root are highly desirable attributes of cassava clones. Theobjective of this study was therefore to evaluate the effect of the genotype x environment interaction (G x E) and the stability ofcassava clones developed at IAC. A subset of eight cassava genotypes was chosen in trials of storage root yield, arranged ina randomized complete block design with four replications, in two counties (Araruna and Maringá), in the northwesternregion of Paraná State, over five growing seasons (1997-2001). The G x E interaction was evaluated by joint varianceanalysis and stability and adaptability by AMMI analysis. The G x E interaction was significant (P<0.05) for storage rootyield. Results indicated AMMI analysis as an efficient tool for the evaluation of phenotypic adaptability and stability of cassavaclones and IAC 190 as the most promising clone

Genetic diversity and population structure of sweet cassava using simple sequence repeat (SSR) molecular markers

The objective of this study was to evaluate the population structure and genetic diversity among 66 sweet cassava (Manihot esculenta Crantz) traditional accessions collected in Maringa, Parana, Brazil, using microsatellite molecular markers. Population structure was analyzed by means of genetic distances and probabilistic models; allelic frequencies were used in order to assess the genetic diversity indexes (Ht , Ho, PIC, % polymorphism and number of alleles) for each locus studied. All evaluated loci were polymorphic and the average was highly heterozygote. The number of alleles per locus was low, suggesting that restrict genetic base is a consequence of accession exchange and a reduced number of ancestors in the population. The polymorphic information content (PIC) values showed considerable genetic diversity with a mean value of 0.5076 and peak of 0.5707 for locus GA140. The microsatellites markers revealed a wide genetic variability among the traditional accessions evaluated. Moreover, the sweet cassava populations were separated in two groups using two analytical methods (probabilistic and genetic distances). The most divergent accessions were BGM 17, BGM 20, BGM 51 and BGM 95. On the other hand, the most similar accessions were BGM 25, BGM 33, BGM 37, BGM 59 and BGM 214. Hybrid combinations formed by the most divergent combinations, especially between BGM 51 × BGM 296, BGM 95 × BGM 222 and BGM 20 × BGM 12, are the most promising ones for future sweet cassava breeding programsFil: Costa, Tiago Ribeiro Da. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Vidigal Filho, Pedro Soares. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Gonçalves Vidigal, Maria Celeste. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Galván, Marta Zulema. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Salta-Jujuy. Estación Experimental Agropecuaria Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Fisiología Vegetal; ArgentinaFil: Lacanallo, Giselly Figueiredo. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Silva, Luciano Ivano Da . Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Kvitschal, Marcus Vinicius. Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina; Brasi

Genetic diversity and population structure of cotton (Gossypium hirsutum L. race latifolium H.) using microsatellite markers

Cotton (Gossypium spp.) is the world?s leading natural fiber crop and is cultivated in diverse temperate and tropical areas. The proper use of cotton genetic resources allows breeders to identify and select superior parents for breeding programs. In this sense, molecular markers are important tools for polymorphism identification in genetic diversity analyses. The objective of this study was to evaluate genetic diversity and population structure in tetraploid cotton (Gossypium hirsutum L. race latifolium H.) by means of microsatellite markers. 43 cultivars and inbred lines from Africa, United States and Brazil were analyzed. From a total of 33 SSRs markers, 15 markers revealed 104 polymorphic SSR alleles. Four groups were identified applying different methods (the probabilistic method, principal coordinates analysis and neighbor joining tree). American cultivars and inbred lines were included in group I; African cultivars in group II; and Brazilian cultivars in groups II, III and IV. The FST index indicated high genetic variability among the cultivars and inbred lines studied. In general, American cultivars were the most divergent in relation to African and Brazilian ones. The dissimilarity index ranged from 0.06 to 0.90 and the lowest genetic divergence was observed between TAMCOT22 and TAM96WD-69s(L). Combination of American cultivars and inbred lines with African and Brazilian cultivars is recommended to obtain superior transgressive segregants in order to improve yield in cotton breeding programs.Fil: Domingos Moiana, Leonel. No especifíca;Fil: Soares Vidigal Filho, Pedro. Universidade Estadual de Maringá; BrasilFil: Gonçalves Vidigal, Maria Celeste. Universidade Estadual de Maringá; BrasilFil: Figueiredo Lacanallo, Giselly. Universidade Estadual de Maringá; BrasilFil: Galván, Marta Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: de Carvalho, Luiz Paulo. No especifíca;Fil: Maleia, Manuel Pedro. No especifíca;Fil: Maritza Pacheco, Cynthia. Universidade Estadual de Maringá; BrasilFil: Ribeiro, Tiago. Universidade Estadual de Maringá; BrasilFil: Zeni Neto, Hugo. Universidade Estadual de Maringá; BrasilFil: Kelly Coimbra, Gislayne. Universidade Estadual de Maringá; Brasi

Genetic control on the performance of common bean differential cultivars to Colletotrichum lindemuthianum races

The aim of this work was to perform genetic control on differential cultivars Michelite, Michigan Dark Red Kidney, Perry Marrow, Cornell 49-242, PI 207262, AB 136 and G 2333 and its diallel hybrids by using Hayman's methodology. The entire F1s populations were evaluated in relation to race 89, whereas the race 31, the diallel scheme did not include the cultivar G 2333. The results showed that the additive effects were predominant for the 31 race, while non-additive effects were more important for race 89. The results demonstrated a high coefficient of genetic determination for the race 31. The G 2333, AB 136 and PI 207262 cultivars should be recommended obtaining cultivar resistant to anthracnose by backcross programs because theyshowed the highest proportion of resistant dominant alleles for the races 31 and 89.Dentre as várias doenças que causam problemas no cultivo de feijão comum (Phaseolus vulgaris L.), uma das mais importantes é a antracnose causada pelo fungo Colletotrichum lindemuthianum (Saac. et Magn.) Scrib., a qual pode resultar em severas perdas na produtividade de grãos. O controle genético, nas cultivares diferenciais Michelite, Michigan Dark Red Kidney, Perry Marrow, Cornell 49-242, PI 207262, AB 136 e G 2333 e seus 21 híbridos dialélicos, foi obtido usando a metodologia de Hayman (1954). Todas as populações F1s foram avaliadas em relação à raça 89, enquanto que os híbridos envolvendo a cultivar G 2333 não foram avaliados com a raça 31. Os resultados demonstraram que os efeitos aditivos foram predominantes para a raça 31, enquanto os efeitos gênicos não aditivos foram mais importantes na reação de incompatibilidade das cultivares a raça 89. Os resultados ainda evidenciaram um elevado coeficiente de determinação genética para a raça 31. Os cultivares G 2333, AB 136 e PI 207262 são os mais indicados para programas de melhoramento visando à obtenção de cultivares resistentes à antracnose por possuírem maior proporção de alelos dominantes para resistência às raças 31 e 89

Characterization of Colletotrichum lindemuthianum isolates using differential cultivars of common bean in Santa Catarina State, Brazil

In 2003 and 2004, 32 isolates of Colletotrichum lindemuthianum obtained from the infected plants of field-grown common bean (Phaseolus vulgaris L.) in Santa Catarina state, Brazil were analyzed based on the virulence to 12 differential cultivars of Phaseolus vulgaris L.. Thirteen distinct races were identified, six of which had not been reported previously in Santa Catarina. This is the first report of the occurrence of 67, 83,101,103,105, and 581 races of C. lindemuthianum. Race 65 was most common (34%). All the isolates were compatible to the cultivars Michelite and Mexico 222. Some isolates infected not only differential cultivar of Mesoamerican origin, but also the ones of Andean origin.Em 2003 e 2004, isolados de Colletotrichum lindemuthianum obtidas de plantas infectadas de feijoeiro comum (Phaseolus vulgaris L.) no Estado de Santa Catarina, Brasil foram analisadas baseando-se na virulência em 12 cultivares diferenciadoras de Phaseolus vulgaris L.. Treze raças distintas foram identificadas, sendo que seis delas não haviam sido reportadas anteriormente em Santa Catarina. Este é o primeiro registro de ocorrência das raças 67, 83, 101,103,105, e 581 do C. lindemuthianum. A raça mais comum foi a 65 (34%). Todos os isolados foram compatíveis com as cultivares Michelite e México 222. Alguns dos isolados infectaram tanto cultivares diferenciadoras de origem Mesoamericana como de origem Andina