Storage, desiccation tolerance and the physiological potential of corn hybrids seeds and their reciprocal

Author(s)

Juliana Faria dos Santos

• Document type: Doctoral Thesis
• Press: Jaboticabal. 2016-02-24.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2016-02-01
• Advisor: Roberval Daiton Vieira

Abstract

Obtaining corn hybrid seeds (Zea mays L.) with high physiological potential depend on the parental lineages used in a cross. Furthermore, the direction of crossing can result in differential phenotypic expression between hybrids, mainly due to the maternal inheritance, influencing the storage capacity and the desiccation tolerance. Thus, this research aimed to evaluate the physiological quality of corn hybrid seeds and their reciprocal, relate chemical and biochemical changes with seed vigor and to verify the influence of storage and seed water content at harvest. The research was divided into three phases, using single-cross corn hybrids and their reciprocal. In Phase 1, seeds were evaluated by germination and vigor tests during storage, as well as electrophoretic analysis of -amylase, catalase and superoxide dismutase and LEA proteins after nine months of storage. In Phase 2, seeds were analyzed for chemical composition, by quantifying and separation by electrophoresis of storage proteins and quantification of soluble sugars. In Phase 3, seeds harvested with four different seed water contents (40, 35, 30, and 25%) were also evaluated according to the physiological potential during storage. There are reciprocal effect of parental lines used in this study, and this phenomenon was verified in the physiological potential, chemical composition and enzyme pattern of corn hybrid seeds, however, the intensity of reciprocity is variable depending on the combination of lineages in a cross. High concentrations of reducing monosaccharides (glucose and fructose) are associated with low vigor corn seeds, allowing to differentiate hybrids produced from reciprocal crosses. The -amylase and catalase can be used for identifying corn hybrids of low physiological quality and differentiation of genotypes in breeding programs. The storage and seed water content at harvest may be variable depending on the hybrid considered. (AU)

• FAPESP's process: 11/23257-1 - Performance of hybrid maize seeds: reciprocal efect of parental lines, physiological potential and desiccation tolerance.
• Grantee: Juliana Faria dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate