Is it possible to determine the physiological maturity of the corn seeds (Zea mays) using the tetrazolium salt?

Author(s)

Luiz Felipe Nicoleti Torrezan

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2016-04-29

Examining board members

Ana Dionisia da Luz Coelho Novembre; Antonio Joaquim Braga Pereira Braz; Cláudio Roberto Segatelli

• Advisor: Ana Dionisia da Luz Coelho Novembre

Abstract

In this study were evaluated the use of the tetrazolium salt to determine corn seed physiological maturity. The seeds used were the hybrids 4285 Pioneer and Dow 2B587, planted on 10.03.2014 and 05.12.2014 respectively, and harvested after 40 days after flowering (DAF), with 4-day intervals until 68 DAF. The harvested seeds were evaluated for viability and vigor (germination test, seedling emergence, electrical conductivity test, accelerated aging test and seedling length). The parameters used to determine the seeds physiological maturity were the black layer, the milk line, the seed dry matter, seed water content and the evaluation of seed tissues using the tetrazolium salt, method to assess seed viability associated to the evaluation of chalaza cells the endosperm cells. The seeds corn germination, both hybrids, was greater than 95% and there is no difference between harvest times. Corn seed physiological maturity (PM) was identified at 56 DAF for both hybrids, P4285 and 48 DAF for hybrid Dow 2B587 and corresponded to stage 4 of the milk line and the accumulation of maximum dry matter. The maximum vigor was detected by accelerated aging test eight days before PM, for the two seed hybrids. The activity of endosperm cells is related to the other PM indicators (milk line, black layer, dry matter and water content). The transport of the nutrients from plant to the seed ceases at the seed physiological maturity, disabling the transport through chalaza cells and basal area. The use of the tetrazolium salt allows identifying the cell death of basal region, since from that time no further reaction of these cells as the tetrazolium salt indicating that these do not already have cell activity. This parameter corresponds to the others evaluated, thus demonstrating that the tetrazolium salt is effective for corn seed physiological maturity characterization. (AU)

• FAPESP's process: 14/13851-1 - Is it possible determine the physiological maturity of seed corn (Zea mays) by tetrazolium salt?
• Grantee: Luiz Felipe Nicoleti Torrezan
• Support Opportunities: Scholarships in Brazil - Master