Background The co-inoculation of soybean with Bradyrhizobium and other plant growth-promoting rhizobacteria (PGPR) is considered a promising technology. However, there has been little quantitative analysis of the effects of this technique on yield variables. In this context, the present study aiming to provide a quantification of the effects of the co-inoculation of Bradyrhizobium and PGPR on the soybean crop using a meta-analysis approach. Methods A total of 42 published articles were examined, all of which considered the effects of co-inoculation of PGPR and Bradyrhizobium on the number of nodules, nodule biomass, root biomass, shoot biomass, shoot nitrogen content, and grain yield of soybean. We also determined whether the genus of the PGPR used as co-inoculant, as well as the experimental conditions, altered the effect size of the PGPR. Results The co-inoculation technology resulted in a significant increase in nodule number (11.40%), nodule biomass (6.47%), root biomass (12.84%), and shoot biomass (6.53%). Despite these positive results, no significant increase was observed in shoot nitrogen content and grain yield. The response of the co-inoculation varied according to the PGPR genus used as co-inoculant, as well as with the experimental conditions. In general, the genera Azospirillum, Bacillus, and Pseudomonas were more effective than Serratia. Overall, the observed increments were more pronounced under pot than that of field conditions. Collectively, this study summarize that co-inoculation improves plant development and increases nodulation, which may be important in overcoming nutritional limitations and potential stresses during the plant growth cycle, even though significant increases in grain yield have not been evidenced by this data meta-analysis.

Anthracnose, caused by Colletotrichum lindemuthianum, is a major disease of dry bean and results great yield losses. The objective of this work was to characterize the anthracnose resistance gene present in the Andean cultivar ÔPitangaÕ. This cultivar was crossed with the cultivars Michelite, Michigan Dark Red Kidney, Cornell 49-242, Mexico 222, PI 207262, TU, AB 136, G 2333, BAT 93, SEL 1308, H1 line, Ouro Negro, Jalo Vermelho and Jalo Listras Pretas to obtain F 1 and F 2 populations. These populations were then inoculated with races 23, 64, 65, 73 and 2047 of C. lindemuthianum. The segregation ratio was 3 resistant : 1 susceptible, which shows that resistance inheritance is controlled by a single dominant gene. The results from allelism tests in fourteen F 2 populations fit a 15 resistant : 1 susceptible ratio, which indicates that the resistance present in the ÔPitangaÕ cultivar is dominant and independent from genes and alleles already characterized: Co-1, Co-2, Co-3, Co-4 2 , Co-5, Co-6, Co-7, Co-9, Co-10, Co-11, Co-12 and Co-13. The authors suggest the symbol Co-14 to represent the gene present in the ÔPitangaÕ cultivar.

A newly emerged disease, the Pyricularia blast caused by Pyricularia grisea, is commonly observed on wheat and black oats, since its discovery in 1985. Within a few years the disease spread to other species of Gramineae, but white oat cultivars remained resistant and were the only ones among cultivated cereals resistant to this disease. In 2012, one commercial field of white oat cultivar IAC 7 was found severely attacked by Pyricularia blast in Assis, in the state of São Paulo. The objective of the present investigation was to find out whether other white oat cultivars are also susceptible to the new P. grisea isolate from cv. IAC 7 and to determine the pathogenic variability, if any, among P. grisea isolates from black oats. Thirty-three white oat cultivars, along with some cultivars of black oat, barley, wheat, triticale, and rye were evaluated against the IAC 7 isolate. Results of disease severity analysis indicated that four white oat cultivars were resistant, seven were moderately resistant and the remaining were susceptible or highly susceptible. Five wheat cultivars were also resistant. Pathogenic variation among P. grisea isolates from black oats was observed.

Earlier studies showed that the resistance of cotton genotype FMT 02102996 to Ramularia areola is governed by one dominant gene. More recently, the resistance of another genotype CNPA BA 2003-2059 to R. areola was detected under field and glasshouse conditions. Present investigation was conducted to verify the mechanism of resistance of the genotype CNPA BA 2003-2059 and to find out if the resistance of these two genotypes is governed by the same or by different genes. Segregating plant populations derived from the cross between the resistant genotype CNPA BA 2003-2059 and the susceptible genotype FMT 701, the back cross populations, as well as those derived from the cross between the two resistant genotypes were evaluated for disease severity by artificial inoculations under glasshouse conditions. The ratio of plants segregating for resistance and susceptibility was studied by χ2 test. The results indicated that the resistance to R. areola in genotype CNPA BA 2003-2059 is governed by one dominant gene and that the resistance in each one of the resistant genotypes is governed by a different dominant gene. These results may assist the local breeding programs aimed at pyramiding resistance genes to this pathogen and may form the basis for genetic mapping of resistance genes. Key words: Gossypium hirsutum, genetics, inheritance of resistance. RESUMO Mecanismo de resistência e presença de genes diferentes de resistência a Ramularia areola em dois genótipos de algodoeiroA mancha-de-ramulária, causada por Ramularia areola, é uma das doenças de importância econômica para o Brasil. Estudos anteriores demonstraram que a herança da resistência do genótipo FMT 02102996 a R. areola é governada por um gene dominante. Recentemente, a resistência do genótipo CNPA BA 2003-2059 a este patógeno foi verificada em casa de vegetação e no campo. O presente estudo foi realizado para verificar o mecanismo de resistência deste genótipo e verificar se os genes de resistência dos dois genótipos resistentes são os mesmos. Foram avaliadas populações segregantes derivadas do cruzamento entre o genótipo resistente CNPA BA 2003-2059 e o genótipo suscetível FMT 701, dos retrocruzamentos, e também do cruzamento entre os dois genótipos resistentes. As plantas foram classificadas como resistentes ou suscetíveis por meio de inoculação artificial. Com base nos resultados, constatou-se que a resistência do genótipo CNPA BA 2003-2059 é condicionada por um gene dominante e que os dois genótipos possuem um gene diferente de resistência. Estes resultados podem auxiliar o planejamento dos programas de melhoramento do algodoeiro visando piramidar genes de resistência a R. areola em novas cultivares, ao mesmo tempo constituindo informação básica para o início de trabalhos de mapeamento genético deste gene de resistência. Palavras-chave: Gossypium hirsutum, genética, herança de resistência.

One of the main problems in pepper seed production is the uneven maturation of the fruits due to the continuous flowering period of the plant, making it difficult to harvest all the fruits at the same time. Thus, studies on fruit maturation stage and seed physiological potential are extremely important in order to identify the appropriate harvest time, avoiding seed deterioration. The aim of this study was to evaluate the physiological potential of five genotypes of “dedo de moça” pepper seeds (Capsicum baccatum var. pendulum) in three maturation stages (green, orange and red), with and without 10-day rest period after harvest date. Physiological potential and vigor of seeds were evaluated through germination tests (first count, accelerated aging and electrical conductivity). The observed results were submitted to variance analysis, comparing averages through Tukey test and principal components analysis. In general, red fruits reflected seed maturity since they provided maximum germination. On the other hand, even fruits harvested at a maturation stage prior to red (green and orange), showed the benefits of the rest periods on germination and vigor characteristics, being this result more evident in green fruits which, initially, had lower physiological potential. The evaluated genotypes showed lower physiological potential of fruits harvested at the green stage, without 10-day rest period.