A alternative to producing litchi (Litchi sinensis Sonn.) seedlings is by cuttings. However, the main drawback of using this method is related to the difficulty of rooting presented by this species. Thus, the objective of this study was to evaluate the rooting of semihardwood cuttings of litchi ‘Bengal’ at different concentrations of indolebutyric acid, with or without incision in the base. The experimental design was completely randomized with five replicates of 10 cuttings in a factorial 3X2 (three IBA concentrations: 0, 1.000 and 2.000 mg L-1; with or without incision in the base). After 126 days, the variables evaluated were: cutting survival, leaf retention, cutting with callus not rooted, rooted cutting, number of roots per cutting, length of major roots per cutting and dry weight of roots per cutting. For rooting, the IBA application was efficient only when the cuttings were not injured. In addition, there was no influence of the types of cuttings in the IBA concentrations. However, in those with incision at the base, the means were higher without the application of the plant growth regulator. Thus, the 'Bengal' litchi can be multiplied by semihardwood cuttings with incision at the base of the cuttings, without the use of IBA.

This work explores polyploidy and its significant implications for plant genetic improvement. Polyploidy, which is characterized by the presence of multiple sets of chromosomes, is an essential evolutionary force that impacts the evolution of plant species. This phenomenon is associated with several advantages, such as greater genetic diversity, vigor and resistance to abiotic and biotic stresses, making it crucial for the development of more productive cultivars adapted to adverse conditions. The study reviews methods of polyploidy induction, including physical, chemical, and biotechnological techniques, and discusses their practical applications, such as in the production of seedless fruits and in increasing biomass. In addition, it addresses the challenges and future prospects, highlighting the need for more research to fully understand its genomic and phenotypic consequences. It is concluded that the exploitation of polyploidy is vital to meet the growing demand for food and face climate change, providing new opportunities in the improvement of several species, including ornamental and medicinal, expanding their economic and ecological potential.

O tomate é uma das hortaliças de maior importância agrícola, e o estabelecimento adequado da cultura está relacionado à qualidade fisiológica das sementes e às condições ambientais durante a germinação. Entre os fatores que podem afetar esse processo, destaca-se a salinidade, que pode reduzir a germinação e o desenvolvimento inicial das plântulas. Nesse sentido, o presente trabalho teve como objetivo avaliar a qualidade fisiológica de sementes de duas cultivares de tomate submetidas a diferentes tratamentos com cloreto de sódio e ácido salicílico. Foram utilizadas sementes das cultivares Cereja e Santa Cruz. Foram avaliadas a germinação, o comprimento da parte aérea e as massas fresca e seca das plântulas. Os dados foram submetidos à análise de variância a 5% de probabilidade e, quando significativo o efeito dos tratamentos, à análise de regressão. O aumento da intensidade do estresse salino reduziu a germinação e o desenvolvimento das plântulas das duas cultivares. Para o ácido salicílico, também foi observada redução da germinação e do desenvolvimento das plântulas com o aumento dos tratamentos utilizados. De forma geral, os tratamentos avaliados influenciaram a qualidade fisiológica das sementes e o desenvolvimento inicial das plântulas de tomate.

Wheat and rice have high economic and food importance, making the use of seeds with proven physical and physiological quality essential. This study aimed to evaluate whether reducing sampling intensity changes the results of mandatory and complementary analyses used in the seed certification system. Sampling was performed in big bags from commercial wheat and rice seed lots, using four collection intensities corresponding to 100, 75, 50 and 25% of the recommended number of primary samples. The samples were analyzed at the Flávio Farias da Rocha Seed Laboratory, Federal University of Pelotas, for physical purity, determination of other seeds, inert material, germination and viability by the tetrazolium test. The results were compared based on the tolerances established in the Rules for Seed Testing, at 5% probability. No significant differences were observed among the evaluated intensities for the studied lots and cultivars. Thus, under the conditions of this study, sampling intensity could be reduced to 25% without impairing the interpretation of laboratory results.