Expressão relativa de genes, caracterização química e estrutural de tegumentos e desempenho de sementes de soja com características contrastantes

• Autor(a) principal: Bahry, Carlos André
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFPel - Guaiaca
• Texto Completo: http://repositorio.ufpel.edu.br/handle/ri/1433
• topic: Tegumentos contrastantes; Genes alvos; Lignina; Camada paliçádica; Qualidade fisiológica; Contrasting seed coats; Target genes; Lignin; Palisade layer; Physiological quality; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::PRODUCAO E BENEFICIAMENTO DE SEMENTES

Soybean seed coats perform as a modulator of the interactions between internal structures of seeds and the external environment, which are vital for its quality. In order to perform a deeper study, four tests were performed. In Test 1, the expression of eight genes was evaluated, possibly related to the quality of the seeds, and express on the seed coats; on Test 2, the seed coats chemical composition was determined; on Test 3, the internal structure of seed coats was analyzed and on Test 4, physical and physiological traits of seeds were evaluated. Four contrasting soybean genotypes were used for the seed coat traits, two yellow seed coats, BMX Potência RR and CD 202, and two black seed coats, TP and IAC. The relative expression of the genes VINV1, SCB1, SCS1, SBP, LEGINSULIN, CHIA1, SGF14c e CHS8* was evaluated through the qPCR technique in seven phases of seed coat development, on the 25, 30, 35, 40, 45, 50 and 55 days after anthesis. Concerning the chemical composition of the seed coats, the phenolic compounds concentration, antioxidant potential, anthocyanin, carotenoids and lignin were determined. For the structural characterization of the seed coats, two anatomic cuts of these in microtome and the documentation of the results were performed by the capture of images on the microscope. Seed quality was evaluated by the germination test and first counting, with and without immersion of the seeds; seedlings length, with and without immersion; emergence in soil; germination and emergence speed index, emergence speed; electric conductivity; a thousand seeds mass; seed coats mass; seed coats mass and seed mass ratio; size of the seeds; imbibitions; and radicle protrusion. Data were subjected to variance analysis and the means compared by the Tukey test on Tests 1, 2 and 4. On Test 4, concerning seed imbibition, a regression analysis was performed. Genes VINV1, SCS1, SBP and LEGINSULIN are more expressed in the early stages of development of the seed coats BMX Potência RR and the gene CHS8* in the final stages of the same genotype. The SCB1 and SGF14c genes are more expressed in early stages of development of the seed coats CD 202 and the CHIA1 gene in the final stages. The phenol concentration, antioxidants, anthocyanin, carotenoids and lignin are higher in the black seed coat genotypes. These also have a palisade layer and thicker hourglass cells than the yellow seed coats. Black seed coats genotypes, specially the IAC presented a higher physiological quality. BMX Power RR has higher seed hydration in comparison to the other genotypes on the first imbibition hours while TP has the lower; however, the latter and the IAC show radicle protrusion more fast. The lignin concentration in seed coats does not influence soybean seeds hydration.