Under salt stress conditions, plant growth is reduced due to osmotic, nutritional and oxidative imbalance. However, salicylic acid acts in the mitigation of this abiotic stress by promoting an increase in growth, photosynthesis, nitrogen metabolism, synthesis of osmoregulators and antioxidant enzymes. In this context, the objective was to evaluate the effect of salicylic acid doses on the growth and physiological changes of eggplant seedlings under salt stress. The experiment was conducted in a greenhouse, where the treatments were distributed in randomized blocks using a central composite matrix Box with five levels of electrical conductivity of irrigation water (CEw) (0.50; 1.08; 2.50; 3.92 and 4.50 dS m^-1), associated with five doses of salicylic acid (SA) (0.00; 0.22; 0.75; 1.28 and 1.50 mM), with four repetitions and each plot composed of three plants. At 40 days after sowing, plant height, stem diameter, number of leaves, leaf area, electrolyte leakage, relative water content, and total dry mass were determined. ECw and SA application influenced the growth and physiological changes of eggplant seedlings. Increasing the ECw reduced growth in the absence of SA. Membrane damage with the use of SA remained stable up to 3.9 dS m^-1 of ECw. The relative water content independent of the CEw increased with 1.0 mM of SA. The use of SA at the concentration of 1.0 mM mitigated the deleterious effect of salinity on seedling growth up to 2.50 dS m^-1 of ECw.

RESUMO Este trabalho teve como objetivo caracterizar a diversidade genética de 80 plantas matrizes de Hymenaea martiana Hayne através da avaliação de características físicas de frutos e sementes, e determinar a correlação dessas características e sua importância no estudo da variabilidade entre as matrizes. A coleta dos frutos foi realizada de diferentes plantas matrizes, localizadas no município de Areia-PB, cujas análises físicas foram: comprimento, largura, espessura e peso dos frutos e das sementes, bem como o número de sementes por frutos. Os dados físicos dos frutos e sementes foram analisados por meio de estatística descritiva, análise de variância pelo teste F, sendo as médias agrupadas por meio do teste de Scott-Knott a 5% de probabilidade. Posteriormente, foi realizada a correlação de Spearman para todas as combinações entre as variáveis e a análise de componentes principais. O comprimento, largura, espessura e peso dos frutos variaram de 27,00 a 186,00 mm; 8,00 a 94,00 mm; 8,20 a 66,32 mm e 3,72 a 222,92 g, respectivamente. As matrizes 88 e 117 apresentaram frutos de maiores dimensões. O número de sementes por fruto foi de 0 a 15, enquanto para as sementes a variação foi de 10,03 a 38,00 mm, 5,30 a 32,39 mm, 1,84 a 35,36 mm e 0,52 a 9,99 g para o comprimento, largura, espessura e peso, respectivamente. As variáveis que mais contribuíram para o componente principal 1 foram as características referentes ao fruto - comprimento (16,4%), largura (16,9%) e peso (19,9%), sendo responsáveis por 53,2% da variação total do componente 1. Enquanto que o número de sementes por fruto (23,5%), espessura da semente (34,7%) e peso da semente (19%) contribuíram com 77,2% da variação total do componente 2. Na população natural de H. martiana, do município de Areia-PB, há divergência em relação às características fenotípicas de frutos e sementes. Das nove características avaliadas, seis têm maior contribuição para a variação total, destacando-se comprimento, largura e peso dos frutos, número de sementes por fruto, espessura e peso da semente.

ISHS V International Mango Symposium REFRIGERATED STORAGE AND CHILLING INJURY DEVELOPMENT OF MANILA MANGOES (MANGIFERA INDICA L.)

Fusarium wilt, caused by Fusarium oxysporum f. sp. vasinfectum, is one of the major diseases of cotton. Preventive methods to manage this disease should be adopted what includes the seed treatment with biocontrol agents as a good alternative. This work aimed to evaluate the efficiency of biological products based on Trichoderma spp. and Bacillus subtilis in the control of Fusarium oxysporum f. sp. vasinfectum (Fov) applied in seeds and seedlings of cotton. The experiment was carried out at the Laboratório de Fitopatologia of the Centro de Ciências Agrárias, of the Universidade Federal de Paraíba (CCA-UFPB), located in the city of Areia, Paraíba - Brazil. The disease transmission of the seeds to the seedlings was evaluated. After the transmission test, cotton seeds of the variety Mocó (Gossypium hirsutum var. Marie-gallante (Watt) Hutch.), BRS 286 and Topázio cultivar (Gossypium hirsutum L.) were submitted to the treatments T1 - Control, T2 - Trichodel^® (0,5 mL); T3-Trichodel^® (1.0 mL); T4-Trichodel^® (1.5 mL); T5-Trichodel^® (2.0 mL); T6-Bactel^® (2.0 mL); T7-Bactel^® (2.5 mL); T8-Bactel^® (3.0 mL); T9-Bactel^® (3.5 mL) diluted in 100 mL SDW; T10 - Fungicide Captana (240 g / 100 kg of seeds) and inoculated with Fov. The pathogen incidence of the seeds was evaluated seven days after the inoculation (DAI). To evaluate the biological control of Fov in the seedlings, the treated seeds were submitted to the following inoculation methods: 1 - inoculation of the substrate with a pathogen conidia suspension; 2 - immersion of the seeds in the conidia suspension and 3 - direct contact of the seeds with the pathogen mycelium. Twenty-one DAI the disease severity and percentage of seedlings with vascular darkening were evaluated. It was observed a transmission rate of 64.0 to 89.0% of the seeds to the seedlings. Trichodel^® reduced the incidence and severity of Fov in the cotton seedlings and was the most efficient product.

Grapevines are propagated by grafting, but the rootstocks used in commercial plantations are susceptible to several diseases. In this study, we focused on a novel root and trunk rot disease of grapevine plantlets that show symptoms during cold storage, before field establishment. Our objectives were to study the aetiology, symptomatology, plant resistance responses, and mode of action of the pathogen that was initially identified as Fusarium. The characterisation of this pathosystem was performed by isolation, pathogenicity assays, genetic diversity studies with BOX-PCR, and identification by sequencing a fragment of the tef1 gene. Scanning electron microscopy and X-ray spectroscopy were used to study the mode of action and plant resistance responses. The results showed that 12 species of Fusarium, initially isolated from both healthy and diseased plantlets, and classified into 4 species complexes, were pathogenic to grapevines. Comparative analyses between diseased and healthy roots showed typical resistance responses in diseased plantlets, including tyloses formation, translocation of Ca, and accumulation of Si. Field experiments confirmed that 100% of the diseased plantlets died within 90 days of transplantation. This study contributes to a better understanding of root and trunk rot disease under cold storage and provides insights for the development of management strategies.