65ª Reunião Anual da SBPC

E. Ciências Agrárias - 1. Agronomia - 4. Fitotecnia

SILICON EFFECT ON CHLOROPHYLLS A AND B IN TWO PEPPER CULTIVARS EXPOSED TO WATER DEFICIENCY

Talitha Soares Pereira - Núcleo de Pesquisa Vegetal Básica e Aplicada, Universidade Federal Rural da Amaz Emilly dos Santos Pereira - Núcleo de Pesquisa Vegetal Básica e Aplicada, Universidade Federal Rural da Amaz Railan do Nascimento Ferreira - Núcleo de Pesquisa Vegetal Básica e Aplicada, Universidade Federal Rural da Amaz Daniele Viana da Costa - Núcleo de Pesquisa Vegetal Básica e Aplicada, Universidade Federal Rural da Amaz Eldenira Barbosa Uchôa - Núcleo de Pesquisa Vegetal Básica e Aplicada, Universidade Federal Rural da Amaz Allan Klynger da Silva Lobato - Prof. M.sc./ Orientador- Núcleo de Pesquisa Vegetal Básica e Aplicada, Universid

INTRODUÇÃO:

The silicon (Si) is considered a benefic element to higher plants with its absorption and deposition in cell walls of several organs such as leaf and stem can promote beneficial effects, and for this reason has been frequently linked to physiological, morphological, nutritional, and molecular aspects in plants. Pepper (Capsicum annuum L.) is a plant used in preparation of foods, condiments, and sauces, being consumed fresh or dehydrated. On worldwide scale, pepper culture has greater economic importance as it is widely used by the population of several countries. Recent studies reveal that the Capsicum genus also has medical properties linked to anti-inflammatory characteristics. In relation to productive performance of pepper plants, water deficit is a key a limiting factor to achieving adequate yield in protected cultivation or under field conditions. The chlorophylls can be divided in chlorophylls a and b with greater occurrence into chloroplasts, besides large interference in photosynthetic apparatus, because are responsible by the conversion of radiation in energy under form of ATP and NADPH, being by this reason directly related with the photosynthetic efficiency in higher plants.

OBJETIVO DO TRABALHO:

This study aims to investigate silicon effect on chlorophylls a and b in two Capsicum annuum cultivars exposed to water deficiency.

MÉTODOS:

The study was carried out in the Instituto de Ciencias Agrárias (ICA) ofthe Universidade Federal Rural da Amazonia, Belem city, Para state, Brazil. In this study were used seeds of pepper (Capsicum annuum L.) cvs. Ikeda and Vermelho Gigante. Substrate to plant growth was composed mix of sand and silic in proportion of 2:1, respectively. The container used to the plant growing was pot type Leonard with 2 L capacity. Experimental design used was completely randomized composed by 5 water conditions (control, deficit + 0.00, deficit + 0.25, deficit + 1.00, and deficit + 1.75 μM Si) combined with 2 cultivars (Ikeda and VermelhoGigante) totalizing 10 treatments. Experiment was assembled with 6 replicates and 60 experimental units, as well as 1 plant in each unit. The determination of the photosynthetic pigments (chlorophylls a, b, and total) were quantified using spectrophotometer, according to the methodology of Lichtenthaler (1987).Data were submitted to variance analysis and when significant differences occurred the Scott-Knott test at 5% level of error probability was applied. Standard errors were calculated in all evaluated points. The statistical analysis was carried out with the SAS software.

RESULTADOS E DISCUSSÃO:

The silicon application proportioned significant effect on levels of chlorophyll a and chlorophyllb, being reported the quadratic equation to relate this effect in both cultivars. For chlorophyll a the silicon promoted increase only in Vermelho Gigante cultivar, and was observed higher value in this parameter under concentration of 0.97 mM Si. In chlorophyll b, the silicon also had positive effects expressed only in Vermelho Gigante cultivar, being higher value in this variable with concentration of 1.01 mM Si. Due to increase in silicone levels occurred partial increment in chlorophyll levels showed only in Vermelho Gigante, being this effect probably provoked by the maintenance in photosynthetic apparatus, combined with improvement in structural architecture of plant, because the silicon deposition kept the leaf with linear aspect, resulting in better luminous absorption and increase in photosynthetic capacity. The silicon action produced increase in level of chlorophyll b in Vermelho Gigante cultivar, while Ikeda cultivar presented decrease in this parameter.

CONCLUSÕES:

Results obtained in this study with Capsicum annuum cultivars submitted to water restriction and silicon application reveal the cultivars evaluated presented different behavior linked to chlorophylls a and b, being showed increase only in Vermelho Gigante cultivar.

Palavras-chave: Capsicum annuum, silicon, Water defict.