ABSTRACT. Removal of lettuce basal leaves is a technique used by the seed industry; however, the effects on seed production and physiological potential are unknown. Genetic dissimilarity is fundamental in the identification of individuals in terms of traits of interest, although it is rarely considered in relation to seeds that are tolerant to thermoinhibition. The aim of this study was to ascertain the relationship between defoliation of lettuce plants and seed yield/physiological quality, as well as the genetic dissimilarity among genotypes with regard to seed thermoinhibition. We used 35 lines of biofortified lettuce, the cultivars Uberlândia 10000, Belíssima, UFU MC BIOFORT1, and Everglades (tolerant to thermoinhibition), and Grand Rapids and Verônica (susceptible to thermoinhibition). The seed yield and physiological quality of the genotypes with and without defoliation were evaluated, artificially aged, and germinated at four temperatures in a factorial arrangement. The genetic dissimilarity was estimated by Tocher graphing and the UPGMA clustering method, based on the Mahalanobis generalized distance (D2 ii). Four UFU genotypes and Grand Rapids had high seed yields. With removal of basal leaves, there was higher seed yield per plant and there was an effect on their physiological quality. The genotypes exhibited genetic variability for thermoinhibition, with UFU-86#2#1#1 and Everglades showing similar performance.

Resumo: Objetivou-se avaliar o efeito da composição genética e arranjo entre progenitores fêmea e macho sobre a tolerância ao atraso na secagem de sementes de milho, avaliando a qualidade fisiológica e a expressão enzimática. As espigas foram colhidas próximo ao ponto de maturidade fisiológica (cerca de 35% de umidade) e genótipos identificados como linhagem 1 (L1), linhagem 2 (L2), híbrido (HB - ♀L1 e ♂L2) e o híbrido recíproco (HR - ♀L2 e ♂L1). Para avaliação da qualidade fisiológica, foi utilizado DIC (4x6x2), constituído de quatro genótipos, seis tempos de atraso antes da secagem artificial (10, 18, 24, 28, 32 e 40 horas) e duas temperaturas no retardamento de secagem (42 e 48 °C). Para avaliar a expressão enzimática, utilizou-se DIC (4x3), consistindo de quatro genótipos e três tempos de atraso antes da secagem artificial (10, 24 e 40 horas) à 48 °C. Em posse dos dados, foram realizados a análise de variância F (p < 0,05), teste de Tukey (p < 0,05) e análise de regressão polinomial. O arranjo das linhagens afeta a tolerância das sementes ao retardamento na secagem. Linhagens suscetíveis não devem ser usadas como parentais femininos. As sementes da linhagem mais suscetível (L2) ao retardamento da secagem apresentam menor expressão de α-amilase (α-AM).

Abstract: This study aimed to evaluate the effect of genetic composition and arrangement between female and male parents on tolerance to delayed drying of maize seeds, evaluating the physiological quality and enzyme expression. Ears were harvested close to the stage of physiological maturity (around 35% moisture) and the genotypes were identified as line 1 (L1), line 2 (L2), the hybrid (HB - ♀L1 and ♂L2), and the reciprocal hybrid (HR - ♀L2 and ♂L1). For assessment of physiological quality, CDR (4x6x2) was used, consisting of four genotypes, six times of delay before artificial drying (10, 18, 24, 28, 32, and 40 hours), and two drying delay temperatures (42 and 48 °C). DIC (4x3) was used for enzymatic expression, consisting of four genotypes and three delay times before artificial drying (10, 24 and 40 hours) at 48 °C. Analysis of variance F (p < 0.05), Tukey’s test (p < 0.05), and analysis of polynomial regressions were performed on the data. Lineage arrangement affects seed tolerance to drying delay. Therefore, susceptible lines should not be used as female parents. The seeds of the line most susceptible (L2) to delay in drying exhibit less expression of α-amylase (α-AM).

Resumo A ampliação da fronteira vitícola brasileira, aliada ao desenvolvimento de novas cultivares adaptadas às diferentes regiões evidenciam a necessidade de maiores informações sobre o manejo da irrigação para novas cultivares, em cultivo protegido. Sendo assim, este trabalho teve como objetivo avaliar cultivares de videira submetidas a diferentes porcentagens de reposição de água no solo, nas condições da região sul de Minas Gerais com o uso de irrigação. O experimento foi implantado e desenvolvido nos anos de 2014 a 2016. O delineamento experimental foi em blocos ao acaso, com cinco repetições. Os tratamentos foram dispostos em parcelas subdivididas, com três porcentagens de reposição (30; 50 e 100 % de reposição necessária de água para esse tipo de solo) e, nas subparcelas, as quatro cultivares de videira pertencentes à espécie Vitis labrusca L. (‘Isabel’, ‘Isabel Precoce’, ‘BRS-Cora’ e ‘BRS-Violeta’). Conclui-se com a pesquisa que as cultivares aumentaram em 75 % o comprimento do cacho, 71 % a massa dos cachos, 39 % a produção de cachos de uva, 52 % o pH, 84 % o teor de sólidos solúveis e 60 % a redução do teor de acidez total com 100 % da reposição de água. A cultivar Isabel precoce nas condições de déficit hídrico obteve os melhores resultados produtivos.

Abstract The expansion of the Brazilian wine border, combined with the development of new cultivars adapted to different regions, highlight the need for more information on irrigation handling for new cultivars in protected cultivation. Therefore, this study aimed to evaluate grapevine cultivars submitted to different percentages of water replacement in the soil in conditions of the Southern region of Minas Gerais with the use of irrigation. The experiment was installed and developed from 2014 to 2016. The experimental design used was random blocks, with five replicates and the treatments were disposed in subdivided plots, with three replacement percentages (30, 50 and 100 % of necessary water replacement for this type of soil) and in the subplots four grapevine cultivars belonging to Vitis labrusca L species. (‘Isabel’, ‘Isabel Precoce’, ‘BRS-Cora’ and ‘BRS-Violeta’). The research concluded that these cultivars increased 75 % the bunch length, 71 % of the bunch weight, 39 % the production of bunch of grapes, 52 % the pH, 84 % the soluble solid content and 60 % the reduction of total acidity content, 60 % to 100 % of water replacement. ‘Isabel precoce’ cultivar in water deficit conditions obtained the best productive results.