Generalized linear models (GLMs) are an extension of the linear model and include the normal, Poisson, and negative binomial distributions. Although GLMs were introduced in 1972, most seed technology studies, especially those involving count data, such as germination tests of seeds from the genus Eucalyptus, still using the analysis of variance, without analysis of the fit of other models. Thus, this study aimed to evaluate the most appropriate model in the GLM class for seed count data of Eucalyptus cloeziana. Data were obtained from a germination test using seeds from three lots of E. cloeziana. Each lot was separated by sieving into three material fractions based on size: small (<0.84 mm), medium (from 1.18 to 1.00 mm), and large (>1.18 mm). The data analysis was based on the use of GLMs adjusted to normal, Poisson, and negative binomial distributions, and the models were evaluated by the Akaike and Bayesian Schwartz criteria and Cook’s distance and half-normal diagnostic graphs. Compared to other adjustments, the normal distribution adjustment differed in the configuration of means submitted to the Tukey test, and although the data met all normality assumptions, the adjustment with the Poisson distribution was the most suitable for the count data from a germination test of E. cloeziana seeds.

Cordia trichotoma (Vell.) Arrab. ex Steud. is a forest species native to Brazil, naturally propagated by seeds, whose quality assessment may be underestimated by the use of inappropriate methods for conducting the germination test. Given the potential use of this plant and the importance of conserving native species, the present work aimed to study parameters for conducting the germination test in louro-pardo seeds, during three consecutive years of evaluations. For this purpose, temperatures (20, 25 and 30 °C) and substrates (blotter paper, filter paper, sand and vermiculite) were tested in seeds collected in different crop seasons. The tests were carried out under a completely randomized experimental design, with four replications, in a factorial scheme for the germination test (temperatures x substrates), with the data obtained being subjected to analysis of variance and means compared by Tukey’s test (p ≤ 0.05). Germination percentage and speed index were determined, and seed health analysis was performed. It is concluded that the germination test for louro-pardo seeds should be carried out between vermiculite, at 30 °C, without light supply, with the first count carried out at 26 days and the last count at 48 days after setting up the test.

Prior to commercialization, seeds of peach palm (Bactris gasipaes Kunth) have to undergo the germination test, whose well-established methodology takes 120 days. Due to their recalcitrant behavior, the seeds have short longevity when stored (around 30-45 days), which makes it challenging to select the most viable ones for marketing. This study aimed to determine a methodology for the tetrazolium test to be carried out in peach palm seeds, in order to fast deliver results that can be correlated to the germination test. Different forms of pre-conditioning, preparation, and staining were investigated via moisture content, germination, and tetrazolium tests, so as to define the vital parts of the seed and sort out the viability classes. For the seed lot under study, the tetrazolium test delivered results supported by the germination test when the following procedures were adopted: pre-conditioning by water submersion (20 °C for 24 h), longitudinal cut adjacent to the embryo, and half-seed immersion (embryo + endosperm) in a 1.0% tetrazolium solution for 4 h at 30 °C. Having fulfilled these criteria, it became possible to separate the peach palm seeds into two classes (viable or non-viable).

Determining the germination speed is essential in experiments in the field of seed technology, as it allows the performance evaluation of a seed lot and the creation of predictive models. To this end, the literature addresses several methods and indexes. The objective of this study was to compare the main methods of emergence speed analysis in seeds, namely the non-linear regression models and the Emergence Speed Index (ESI), with the time-to-event models. The research was conducted with peach palm seeds (Bactris gasipaes) that were measured for viability and vigour through daily evaluations for 4 months. Vigour was evaluated by the quantification of the seed emergence speed, which was performed in three ways: ESI, non-linear regression and non-linear regression considering germination as a time-to-event event. From the results obtained, we conclude that the ESI is not a good indicator to evaluate the emergence speed; the non-linear regression model underestimates the errors and, thus, increases the probability of misclassifying treatments; the time-to-event model is more reliable in classifying treatments according to the emergence speed.

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The evaluation of the genetic quality of a seed lot is crucial for the quality control process in its production and commercialization, as well as in the identification of superior genotypes and the verification of the correct crossing in plant breeding programmes. Current techniques, based on the identification of seed morphological characteristics, require skilled analysts, while biochemical methods are time-consuming and costly. The application of spectral imaging analysis, which combines digital imaging with spectroscopy, is gaining ground as a fast, accurate and non-destructive method. The success of this technique is closely linked to chemometric techniques, which use statistical and mathematical tools in data processing. The aim of the work was to evaluate the main procedures in terms of spectral image analysis and chemometric procedures applied in seed phenotyping and its practical application. A systematic review was conducted using the PRISMA methodology, in which a total of 1304 articles were identified and screened to the inclusion of 44 articles pertaining to the scope. It was concluded that spectral image analysis has a high ability to classify seeds of different genotypes (93.33%) in a range of situations: between cultivars; hybrids and progenitors; and hybrids and lines, as well as in the separation of coated seeds. Accurate classification can be obtained by different strategies, such as the choice of the equipment type, the spectrum range and extra features, guided by the characteristics of the species, as well as in the choice of algorithms and dimensionality reduction procedures for the optimization of models when there is a large amount of data. Despite the fact that the practical application of this technique in seed phenotyping still needs to be developed for use in laboratories with large volumes of analyses, lots, genotypes and harvests. Research has been accelerated to overcome the practical challenges of this method, as seen in works using model update algorithms, online classification systems, and real-time classification maps. Thus, there are strong indications that the application of multispectral image analysis will reach the routine of seed analysis laboratories.

African mahogany (Khaya grandifoliola) is a forest species with excellent wood quality. Due to the increasing demand for viable seeds in forest production programs, the storage capacity of this species must be evaluated. Therefore, this study aimed to determine the appropriate environmental and packaging conditions for the storage of African mahogany seeds. Initially, the water content of the seeds, germination rate, and seedling length were determined in two environments (cold chamber and laboratory), two packages (polyethylene and glass), and three storage periods (72, 144, and 216 d) as well as in additional treatment without storage. The variables analyzed during storage were water content, germination capacity, germination speed index, and seedling length. The experiment was conducted in a completely random design with four repetitions in a split-plot scheme and an additional treatment of 2 × 3 × 2 + 1. African mahogany seeds stored in a cold chamber (6 °C and 72% relative humidity) in a polyethylene packaging maintained their physiological quality for 216 d.

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