Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

Resumo: A Adenanthera pavonina L. é conhecida popularmente por carolinatento, olho-de-dragão ou falso-pau-brasil e suas as sementes tem ganho espaço no mercado do artesanato. O objetivo foi avaliar a biometria dos frutos e sementes de A. pavonina. Frutos e sementes foram colhidos manualmente em duas matrizes presentes no Assentamento Brinco de Ouro, município de João Câmara-RN. Desta forma, utilizou-se 100 frutos e 100 sementes, nos quais se avaliou o peso, o comprimento e o diâmetro das vagens, assim como, o número de sementes por vagem, o peso, o comprimento e o diâmetro das sementes. Os dados biométricos foram analisados por meio de distribuição de classe, com determinação de média, variância e desvio padrão. O comprimento das vagens variou entre 21 a 35 mm, já o peso das vagens variou de 2 a 9 g. Os frutos e sementes de A. pavonina L. submetidas à análise biométrica apresentaram variação em suas características de comprimento, diâmetro e peso não sendo assim considerados uniformes. Entretanto, são necessários estudos que venham gerar conhecimentos morfofisiológicos da espécie, visto que, a mesma, apresenta importância ambiental e econômica. Palavras-chave: Fabaceae; Falso-pau-brasil; Morfologia; Sementes. 1. Introdução A espécie Adenanthera pavonina L. é conhecida popularmente por carolina-tento, olho-de-dragão ou falso-pau-brasil. Nativa da África e Ásia, pertencente à família Fabaceae, subfamília Mimosoideae, apresenta porte arbórea semidecídua, tipicamente tropical, crescimento rápido e anualmente produz acentuada quantidade de semente (LORENZI et al., 2003). As sementes desta espécie tem ganhado espaço no mercado do artesanato, corante, bijuterias. Além disso, segundo Olajide et al. (2004) estas

The germination of papaya seeds is slow and uneven, usually due to inhibitors present in the sarcotesta; however, some removal procedures may cause physical damage, negatively interfering in the physiological quality and field performance. This study aimed to evaluate the physical and physiological quality of papaya seeds submitted to methods of sarcotesta removal by image analysis. Papaya Formosa ‘Tainung 01' seeds were submitted to the following methods of sarcotesta removal: fermentation + sieve, sand + sieve, sieve and blender + sieve. After the sarcotesta removal, the seeds were submitted to tests of germination, first germination count, germination speed and seedling length. For the image analysis, the seeds without sarcotesta were submitted to the X-ray test and to a computerized analysis of seedling images by the SVIS® software. The methods used were only promising for the sarcotesta removal, while the blender + sieve method obtained the highest physical and physiological seed quality, in addition to performing the best sarcotesta removal. However, the image analysis using the SVIS® software allowed to identify the high physical and physiological seed quality using the blender + sieve method, which promoted the highest efficiency in removing the sarcotesta.

Passion fruit seeds present germination problems which are mainly attributed to growth regulating substances present in aryl. The objective of this work was to evaluate the quality of passion fruit seeds submitted to different aryl removal methods by the X-ray test compared to the traditional viability and vigor tests. Seeds extracted from giant yellow passion fruit were purchased from a local market and then subjected to the following aryl removal techniques: water degumming, sand rubbing, mechanical blending, fermentation and virgin lime. After aryl removal, the seeds were submitted to a physiological quality evaluation by the moisture degree, germination, first germination count, germination speed, and seedling length, and also a physical quality evaluation by X-ray test. The treatments using fermentation and virgin lime were harmful to the seeds and the aryl removal techniques of passion fruit seeds by means of degumming in water, sand friction and mechanically with a blender presented the best results. The X-ray test was efficient in identifying mechanical damage and deformations in passion fruit seeds.

Salinity adversely affects plant growth and metabolism by triggering increased production of reactive oxygen species (ROS). Ascorbic acid (AsA) is known to protect organelles and cells against ROS by preventing accumulation. The objective of this study was to study the effects of AsA on cowpea beans under saline stress. Cowpea seeds of the cultivars (BRS Marataoã and Setentão) were conditioned at concentrations of 0.0 (control); 0.25; 0.50; 0.75 and 1.00 mM AsA and seeded on paper towels, moistened at saline levels of 0.0 (control); 1.5; 3.0; 4.5; 6.0 and 7.5 dS.m-1, packed in a bench germinator at 25 °C. The statistical design adopted was a completely randomized 2 × 5 × 6 factorial design (cultivar x ascorbic acid x saline levels) with four replicates of 50 seeds per treatment. The analyzed variables were percentage of germination, first germination count, germination speed index, shoot and root length, total seedling dry weight, and leaf and root electrolyte leakage. Ascorbic acid at concentrations of 0.50 mM for BRS Marataoã and 0.75 mM for the Setentão, enabled the development of more vigorous seedlings and the reduction of membrane damage caused by oxidative stress both in the absence of salt and at the saline levels tested, including the highest one.

O objetivo deste trabalho foi avaliar germinação e desenvolvimento inicial de plântulas de coentro submetidas a três métodos de condicionamento fisiológico por cinco períodos. Houve efeito significativo do método e do tempo de condicionamento para a maioria das variáveis analisadas, sendo o rolo de papel, o que permitiu melhor desempenho de vigor das sementes na maioria dos períodos testados. A germinação e o desenvolvimento inicial das plântulas diminuíram à medida que se aumentou as horas de condicionamento fisiológico.

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A utilização de sementes de boa qualidade é fundamental para o estabelecimento adequado de uma lavoura. Para uma análise mais precisa da qualidade de sementes, faz-se necessária a complementação das informações fornecidas pelo teste de germinação com os testes de vigor, que dentre eles se destaca o de condutividade elétrica, por ser considerado rápido, simples e confiável. O presente trabalho objetivou avaliar a influência da pré-hidratação na eficiência do teste de condutividade elétrica na avaliação do potencial fisiológico em seis lotes de sementes de feijão-caupi cv. Setentão. Inicialmente, procedeu-se à caracterização dos lotes pela determinação do teor de água e pelos testes de germinação e vigor (primeira contagem, índice de velocidade de germinação, emergência em campo, envelhecimento acelerado e condutividade elétrica). Posteriormente, as sementes foram submetidas aos tratamentos de pré-hidratação em substrato úmido por 0, 6, 9, 12, 15 e 18 horas antes da imersão em água, e realizada nova leitura. Tempos de pré-hidratação a partir de nove até quinze horas podem ser utilizados para identificação de diferenças mais sensíveis na qualidade fisiológica de sementes de feijão-caupi.