ABSTRACT The use of longitudinal measurements is an essential practice both in Psidium guajava L. breeding and in other perennial crops in which covariance structures can be introduced to explain the form of dependence between measurements. Hence, this study aimed to analyze six covariance structures to identify one that best described the correlation between the repeated measurements in time in traits of guava full-sib families. The repeatability coefficient for each trait was estimated and the minimum number of evaluations required for estimates representing the population was determined. The work was performed based on average data of three yield-related variables from nine harvests of a guava tree population evaluated from 2011 to 2018. The best model was chosen based on the Akaike and Schwarz Bayesian information criterion. The autoregressive covariance structure best represented the dependencies among families between crops for all traits. The number of variables of fruits and total yield per plant presented repeatability estimates higher than 0.5 and may be essential traits for indirect selection of others, such as fruit mass, which had an estimated repeatability of 0.24, proving low regularity in the repetition of the character from one cycle to another. It was also possible to define four harvests as the minimum acceptable number of observations necessary on the same individual for these traits; therefore, the repetitions represented the individuals. L Hence fullsib full sib determined yieldrelated related 201 2018 criterion 05 0 5 0. others mass 024 24 0.24 another therefore individuals 20 02 2 0.2

Resumo A goiaba é uma fruta de importância no Brasil e no mundo. No entanto, as pesquisas ainda precisam avançar na área de melhoramento genético e na tecnologia de sementes que é fator fundamental na busca de novos genótipos produtivos e com potencial germinativo, dando apoio a continuidade dos programas de melhoramento. Na busca de metodologia para teste de análise de rotina de sementes de goiaba sob controle genético objetivou-se avaliar o efeito da temperatura e do substrato na germinação de sementes de goiaba oriundas de famílias de irmãos completos. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 5 x 4, constituído pela combinação de cinco temperaturas (25, 30, 35, 20-30 e 25-35 °C) e quatro substratos (rolo de papel, sobre papel, entre areia e sobre areia), com oito repetições de 50 sementes. Foram avaliadas a germinação, o índice de velocidade de germinação e sementes não germinadas vivas. As temperaturas alternadas de 20-30 e 25-35 °C e os substratos rolo de papel, sobre papel e entre areia são as condições adequadas para condução de testes de germinação com sementes de goiaba.

Abstract Guava is an important fruit in Brazil and worldwide. However, research has yet to advance on its breeding and seed technology, an essential factor for the development of productive genotypes with germination potential which would support the continuity of breeding programs. In search of a methodology for routine analysis testing of guava seeds under genetic control, this study examined the effect of temperature and substrate on the germination of guava seeds from full-sib families. The experiment was laid out in a completely randomized design with a 5 × 4 factorial arrangement consisting of the combination of five temperatures (25, 30, 35, 20-30 and 25-35 °C) and four substrates (paper roll, on-paper, in-sand and on-sand), with eight replicates of 50 seeds. Germination, germination speed index and live ungerminated seeds were evaluated. The alternating temperatures of 20-30 and 25-35 °C and the paper roll, on-paper and in-sand substrates are adequate conditions for germination tests with guava seeds.