Genótipos de milho e safras nas taxas de haploides putativos com expressão do gene R1-navajo

The objective of this work was to evaluate the influences of the factors corn (Zea mays) genotypes, crop seasons, endosperm texture, genetic background, and genetic basis on putative haploid rates (PHRs) according to the expression of gene R1-navajo (R1-nj). Forty-one corn genotypes were evaluated as pollen receptors, in crosses with the Krasnodar haploid inducer, in two crops (summer and winter), in the municipality of Maringá, in the state of Paraná, Brazil. The experimental design was completely randomized with ten replicates (ears). The response variable analyzed was the PHR, determined by the proportion of putative haploids, obtained through the R1-nj marker, in relation to the number of diploid seeds in each ear. Subsequently, generalized linear models were used to choose the one best fit to explain the PHR in function of the tested factors. Crop seasons, genotypes, and the crop seasons x genotypes interaction affected significantly the PHR, showing the dependence of these factors on the expression of the phenotypic marker based on anthocyanin pigmentation and determined by gene R1-nj. The number of clusters formed by the genotypes was different in each crop season. Ten genotypes showed higher rates in summer than in winter. Endosperm texture, genetic basis, and genetic background did not affect the PHR.O objetivo deste trabalho foi avaliar as influências dos fatores genótipos de milho (Zea mays), safras agrícolas, texturas dos endospermas, fundo genético e bases genéticas nas taxas de haploides putativos (THPs), conforme a expressão do gene R1-navajo (R1-nj). Foram avaliados 41 genótipos de milho como receptores de pólen, em cruzamentos com o indutor “Krasnodar haploid inducer”, em duas safras (verão e inverno), no município de Maringá, no estado do Paraná, Brasil. O delineamento experimental foi o inteiramente casualizado com dez repetições (espigas). A variável resposta analisada foi a THP determinada pela proporção de haploides putativos, obtidos com base no marcador R1-nj, em relação ao número de sementes diploides por espiga. Posteriormente, foram utilizados modelos lineares generalizados para escolher o mais adequado para explicar a THP em função dos fatores testados. As safras, os genótipos e a interação safras x genótipos afetaram significativamente a THP, o que evidencia a dependência destes fatores na expressão do marcador fenotípico baseado na pigmentação por antocianina e determinado pelo gene dominante R1-nj. O número de agrupamentos formados pelos genótipos foram diferentes em cada safra. Dez genótipos apresentaram taxas maiores no verão do que no inverno. As texturas dos endospermas, as bases genéticas e o fundo genético não interferiram na THP

Combining abilities in green corn genotypes for yield and industrial quality traits

The general and specificcombining abilities and the reciprocal effects of seven hybrids and two open pollination varieties of green corn were evaluated, aiming the formation of base populations to be used as a source of superior inbred lines. For the purpose of this study, two experiments were carried out in Maringá/PR and Sabáudia/PR, during the crop season of 2014/15. The experiments were evaluated in incomplete block design alpha lattice, with three replications. The parents AM811, HTMV1, Cativerde 02 and AL Piratininga were selected based on their ĝi and the following hybrid combinations AM811 x CD316, AM811 x AG1051, AM811 x HTMV1, AM606 x Cativerde 02 and Al Piratininga x AG4051 presented the most desirable ŝij effects. Regarding the reciprocal effects, the genotype AM811 is recommended to be used as male parent in further hybrid combination

The effect of high dilutions of Pulsatilla nigricans on the vigour of soybean seeds subjected to accelerated aging=O efeito de altas diluições de Pulsatilla nigricans no vigor de sementes de soja submetidas ao envelhecimento acelerado

The aim of this study was to evaluate the effect of high dilutions of Pulsatilla nigricans in dinamisations 6, 12, 18, 24 and 30 CH on the vigour of soybean seeds subjected to accelerated aging. The experiment was conducted according to a randomised design with 6 treatments and 10 replicates. The treatments consisted of dinamisations 6, 12, 18, 24 and 30 CH and a distilled-water control. After the treatments, the seeds were subjected to accelerated aging (48h at 42ºC) in a growth chamber (25 ± 2ºC). The study evaluated the germination, the length of primary roots and shoots, the fresh weight of roots and shoots and the enzymatic activity of peroxidase (POX-EC1.11.1.7). The variables were analysed by ANOVA, and the means were compared using the Scott-Knott test (p = 0.05). The germination and the fresh weight of roots and shoots of the seedlings treated with Pulsatilla nigricans were higher than the water control, except that CH 30 did not significantly increase the fresh weight of shoots. The dinamisations 6, 24 and 30 CH produced a lower primary root length compared with the control. The dinamisations 12, 18 and 30 CH yielded a greater length of shoots. The total length of seedlings was reduced by the high dilutions 6 and 24 CH.<br><br>O objetivo do presente trabalho foi de avaliar o efeito de altas diluições de Pulsatilla nigricans nas dinamizações 6, 12, 18, 24 e 30 CH, no vigor de sementes de soja submetidas ao envelhecimento acelerado. O experimento foi conduzido em delineamento inteiramente casualizado com 6 tratamentos e 10 repetições. Os tratamentos foram constituídos das dinamizações 6, 12, 18, 24 e 30 CH e testemunha com água destilada. Após aplicação dos tratamentos, as sementes foram submetidas ao teste de envelhecimento acelerado (48h a 42ºC), em câmara de crescimento (25 ± 2ºC). Avaliou-se a germinação, o comprimento da raiz primária e da parte aérea, massa fresca da raiz e da parte aérea e atividade enzimática da peroxidase (POX- EC1.11 .1.7). As variáveis foram analisadas por ANOVA e as médias comparadas pelo teste Scott-Knott a 5%. A germinação e a massa fresca da raiz e da parte aérea das plântulas tratadas com Pulsatilla nigricans foram superiores ao controle com água, exceto na dinamização 30 CH para massa fresca da parte aérea. As dinamizações 6, 24 e 30 CH tiveram menor comprimento da raiz primaria comparadas ao controle. As dinamizações 12, 18 e 30 CH, apresentaram maior comprimento de parte aérea. O comprimento total de plântulas foi reduzido com as diluições 6 e 24 CH

Comparison of three tester parents in evaluating popcorn families derived from IAC-125

ABSTRACT Thirty-eight S3 families obtained by selfing from IAC-125 popcorn hybrid were evaluated by three different topcross tester parents: an inbred line P3.3- S7 generation taken from popcorn population CMS-42, an open-pollinated variety BRS Angela and the commercial three-way hybrid Jade. Manual crossings were performed according to a partial diallel mating design. Topcross hybrids were evaluated in individual experiments for each tester carried out in randomized block designs with three replications in two locations (Maringá-Paraná and Sabáudia-Paraná). The results for grain yield and popping expansion were gathered in a combined analysis. Estimates of general and specific combining ability were obtained according to Griffing's methodology (1956), adapted by Geraldi and Miranda Filho (1988). The hybrid Jade was considered the most appropriate tester because it discriminated the evaluated families well for both grain yield and popping expansion according to Fasoulas index of differentiation. Families F4, F7, F16 and F31 are the most promising due to their high general combining ability for both traits as well their performance regardless of the effect of locations