Quick tests are essential tools to evaluate seed quality. The objective of this study was to adapt the methodology of tetrazolium test, by identifying the most suitable pre-conditioning parameters of imbibition temperature and duration, and tetrazolium solution concentrations, in order to assess the physiological quality of chickpea seeds. Also, this work proposed the separation of lots in classes, according to the viability and vigor of the seeds. Three lots of chickpeas (lot 1 - BRS Aleppo C1, lot 2 - BRS Aleppo basic, and lot 3 - Cicero) were evaluated. They were analyzed according to three combinations of imbibition temperature and duration (41 °C for 4 hours, 41 ºC for 6 hours, and 30 ºC for 18 hours) and two tetrazolium concentrations (0.1% and 0.5%). The imbibition at 41 °C for 4 or 6 hours, and at 30 ºC for 18 hours allowed clear visualization of injuries in the seeds after immersion in 0.1% tetrazolium solution. The intense coloration formed by the 0.5% solution of this salt prevented the differentiation of the types of damage. In addition, it was possible to separate the seeds into four classes: class I (viable and vigorous, without damages), class II (viable and vigorous, with superficial injuries), class III (viable and non-vigorous), and class IV (non-viable).

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The improvement of sweet potato is a costly job due to the large number of characteristics to be analyzed for the selection of the best genotypes, making it necessary to adopt new technologies, such as the use of images, associated with the phenotyping process. The objective of this research was to develop a methodology for the phenotyping of the root production aiming genetic improvement of half-sib sweet potato progenies through computational analysis of images and to compare its performance to the traditional methodology of evaluation. Sixteen half-sib sweet potato families in a randomized block design with 4 replications were evaluated. At plant level, the weight per root and the total number of roots were evaluated. The images were acquired in a “studio” made of mdf with a digital camera model Canon PowerShotSX400 IS, under artificial lighting. The evaluations were carried out using the R software, where a second-degree polynomial regression model was fitted to predict the root weight (in grams) and the genetic values and expected gains were obtained. It was possible to predict the root weight at plant and plot level, obtaining high coefficients of determination between the predicted and observed weight. Computer vision allowed the prediction of root weight, maintaining the genotype ranking and consequently the similarity between the expected gains with the selection. Thus, the use of images is an efficient tool for sweet potato genetic improvement programs, assisting in the crop phenotyping process.

O semiárido mineiro inclui as mesorregiões Norte e Jequitinhonha, abrangendo uma população superior a dois milhões de habitantes em 140 municípios, o que equivale a 10,46% da área brasileira em que predomina este clima. Entre as diversas dificuldades para a otimização do sistema produtivo da agricultura familiar nestas mesorregiões, destaca-se a escassez de sementes crioulas adaptadas aos agroecossistemas específicos, que são bastante distintos das áreas experimentais utilizadas pelo melhoramento genético convencional. Com o declínio de pequenos produtores, perdem-se, também, variedades locais e o conhecimento tradicional associado – um dano incalculável pela perda de reservatórios gênicos. Diante disso executou-se no interstício dos anos de 2017 a 2021, um projeto intitulado "Melhoramento Participativo de Milho com Enfoque na Agrobiodiversidade do Semiárido Mineiro", com fomento aprovado pelo Banco do Nordeste. Foram realizadas visitas técnicas em diversas comunidades rurais nas áreas de abrangência, coletando-se relatos sobre variedades locais muitíssimo escassas. A despeito deste franco processo de erosão de genética, obteve-se, com muita procura, amostras de sementes fidedignas dessa categoria. Os depósitos ocorreram no Laboratório de Biotecnologia da Universidade Federal de Minas Gerais - UFMG (campus Montes Claros), totalizando 44 variedades resgatadas, às quais foram caracterizadas por meio de oligonucleotídeos do tipo ISSR (Inter Simple Sequences Repeats). Os diagnósticos locais comunitários, ainda que morosos e pouco céleres, permitiram recuperar preciosos genótipos de milhos crioulos, fontes de variabilidade para tolerância a estresses causados por pragas, doenças e limitações de clima, todos estes contextualizados ao semiárido.