The present study resulted from the lack of information on the genotypic expression ruling the resistance to rust and on the main traits of economic importance to the herein addressed crop. The combining ability of 16 popcorn lines and hybrids was assessed in partial diallel cross in two representative locations in Rio de Janeiro State, Brazil, where forty simple hybrids were obtained. The experiments followed a completely randomized block design with four repetitions and were conducted under natural infestation conditions in order to test the southern rust severity in the entire plant (SSW) and in the leaf of the first ear (SFPE), as well as the morpho-agronomic traits of greater interest: grain yield (GY) and popping expansion (PE). Additive gene effects prevailed in PE and the non-additive ones stood out in GY; however, both gene effects were important to the southern rust resistance characteristics (SSW and SFPE). Hybrids L65 × P10 and P7 × L70 presented appropriate specific combining ability (SCA) values in all traits; therefore, they were promising for the selection of superior genotypes. Lines L80, L76 and L77 expressed negative general combining ability (GCA) values in SSW and SFPE; line P10 recorded high and positiveGCA values in GY and PE.

The aim of this study was to estimate the effects of populations and mother trees over some characteristics on pequi (Caryocar brasiliense Camb.) fruits as well as their repeatability coefficient. Data came from two populations with 15 mother trees each, covering three years. The following physical and chemical characteristics were evaluated: total fruit weight; external mesocarp weight; number of putamens per fruit; total weight of putamens; total and average pulp weight; and proportion of the weight of lipids and proteins in relation to pulp weight. Analysis of variance was performed using a nested design model. The effects of mother trees within populations were highly significant for all variables under study, while the effects of populations were not for any characteristic, showing that for populations and mother trees, efforts must be focused on the number of mother trees per population rather than on populations. The estimated repeatability coefficients showed high genetic control for total fruit weight; external mesocarp weight; average weight of putamens; average pulp weight; and proportion of the weight of lipids in relation to pulp weight. Therefore, the expression of these characteristics on descendants, by cloning selected mother trees, is likely to be effective.

Climate variation throughout the year affects photosynthesis and other physiological processes correlated with plant development and yield. This study aimed to evaluate the changes in the physiological attributes of Coffea canephora genotypes over the year in the Brazilian Amazon and assess their relationship with crop yield. The experiment was carried out in three cultivation systems with three genotypes. The evaluations were carried out in four periods: the peak of the dry season (S1); the beginning of the rainy season (S2); the peak of the rainy season (S3); and the beginning of the dry season (S4). A dataset of gas exchange, pigment indices, chlorophyll fluorescence, branch growth, and coffee yield was obtained. The group of gas exchange variables was the main contributor to treatment discrimination and was most affected by seasons. As expected, the values of g_s, E, and A were significantly lower in S1, while the values of VPD_Leaf-ar, T_Leaf, and IWUE were significantly higher. Our results demonstrate that climatic seasonality affects the photosynthesis of Amazonian Robustas coffee, even under irrigated conditions, particularly in response to increased VPD. The physiological variables analyzed at the leaf level, even in different periods, did not explain the differences in the yield of C. canephora.

Conflicting responses have been found for the period of conservation of passion fruit seeds. Therefore, this study aimed to evaluate the response of the seeds of passion fruit progenies to a 24-month storage period. The sour passion fruit progenies from the third cycle of Universidade Estadual do Norte Fluminense Darcy Ribeiro - UENF intrapopulation recurrent selection program were grown in Itaocara- RJ and the progenies seeds were evaluated for: germination potential, germination first count, accelerated aging, first count of accelerated aging test, seedling and radicle size and germination speed index. The germination and vigor of the seeds of the full-sib progenies were assessed by analysis of variance and factorial arrangement with 3 progenies and 7 periods of storage and the averages were compared by Tukey test at 5% probability. Progenies 1 and 2 responded better to germination (92% for both progeny) and vigor test of accelerated aging (92% for both progeny), rootlet size (6.4 and 5.8 cm, respectively) and germination speed index (2.91 and 2.85, respectively) during storage. Variations were observed during the storage period in mean of progenies for germination (81-93%) and vigor for all traits, except accelerated aging (84-91%). At eight months of storage, the seeds presented increased vigor; at 16 months, they showed reduced vigor. The passion fruit seeds of the progenies under analysis can be stored for up to 24 months with high and uniform germination rate and no loss in vigor. The seeds from the passion fruit breeding program showed increases in the variables of germination and vigor during the selection process for fruit production variables, proving the efficiency of the breeding program.