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ABSTRACT This study aimed to estimate the genetic parameters, genetic correlations, genetic dissimilarity, and predicted gains with the selection of interspecific apomictic Paspalum plicatulum × Paspalum guenoarum hybrids in relation to seed yield traits. Nineteen genotypes that showed increased forage yield in previous studies were planted in a randomized complete block design with ten blocks. Traits evaluated in this study were: number of tillers/plant, number of reproductive tillers/plant, number of racemes/inflorescence, number of seeds/inflorescence, weight of a thousand seeds, and seed yield. Data were analyzed using a mixed model approach. The genotypes evaluated in our study showed improvement potential in relation to high heritability (H a 2 > 0.50 ), high precision (Acgen> 90%), and genetic dissimilarity (forming three groups) for seed yield traits. Seed yield showed high correlation to reproductive tillers that can be used as indirect selection tools for genetic improvement of seed yield.

ABSTRACT The objective of this study was to identify the most efficient method for overcoming coat-imposed dormancy and determine the optimal germination temperature for Ornithopus pinnatus seeds. Treatments to overcome dormancy were: intact seeds; immersion in hot water at 60 ºC, followed by soaking in the same water (unheated)/24 h; immersion in hot water at 90 ºC, followed by soaking in the same water (unheated)/24 h; mechanical scarification; chemical scarification, H2SO4/5 min; and chemical scarification, H2SO4/10 min. Percentages were calculated for germinated, abnormal, dormant, and dead seeds. Optimal germination temperatures were calculated using eight constant temperatures (0, 5, 10, 15, 20, 25, 30, and 35 °C), with 8 h of light and 16 h of darkness. Germination rate, frequency, and synchronization index of germination were used as parameters to establish optimum temperature for germination. A completely randomized experimental design was used, with twelve repetitions of 100 seeds per treatment. Data obtained were subjected to analysis of variance and Tukey's test at a 5% significance level. O. pinnatus seeds exhibit dormancy caused by the seed coat's impermeability to water. Mechanical scarification was efficient in promoting seed germination. The species is stenothermal, meaning it cannot tolerate significant temperature variations. The germination rate of seeds was linearly dependent on temperature. Synchronization of the germination process is greater in the optimum temperature range, established between 15 and 20 °C.