A multivariate approach to the physical and physiological quality of hybrid corn seeds affected by Molicutes and MRFV

Abstract

This study aimed to assess physical and physiological seed quality attributes and seed vigor in different hybrids presenting different corn stunt complex severity levels, molicutes and Maize rayado fino virus (MRFV). This was performed through a multivariate approach, in order to select high vigor seeds and more disease-tolerant hybrids, as well as identify the main vigor variables. Seeds from three corn hybrids (H1, H2 and H3) obtained from seed production fields were assessed, each presenting three levels of corn stunt complex ear severity (healthy, medium and high). Seed quality was assessed using physical and physiological quality attributes. The data were subjected to an analysis of variance and, when significant, assessed through factor analysis, Scott–Knott test (p < 0.05) for the selected variables, and cluster analysis. A gradual reduction in seed vigor quality attributes due to increased corn stunt complex severity level was detected. Hybrid seeds from ears presenting medium and high severity corn stunt complex were less vigorous than seeds from healthy ears, which were asymptomatic and presented normal development. Comparing hybrids with regard to severity level, the H2 was most susceptible and the H1, most tolerant to molicutes and MRFV. Of the 37 analyzed variables, seven displayed the greatest indicator potential and were considered the most relevant in explaining seed performance alterations concerning the assessed physical and physiological attributes, emphasizing the importance of both for quality control and genetic improvement programs aiming at high vigor seed and more tolerant hybrids with regard to corn stunt selection.