Effect of osmotic potential and seed size on germination and seedling growth in corn (Zea mays L.) under laboratory conditions

Abstract

Seed germination and seedling growth were studied from three seed sizes of two corn cultivars evaluated in absorbent paper and watered with three osmotic solutions created with sucrose. A split-split-plot design was used with four replications; main plots were constituted for the osmotic potentials (0.0, - 0.6 and -1.2 MPa), sub-plots were the two corn cultivars (Himeca 95 and Pioneer 3031) and sub-sub-plots were three seed sizes (< 0.32 g; ≥ 0.32 – 0.36 ≤ g y > 0.36 g). An analysis of variance and Duncan’s multiple range test were carried out. The inference level was 5%. The potential osmotic of -1.2 MPa caused a decreasing of germination in cv. Himeca 95, but cv. Pioneer 3031 was unaffected; in general, decreased osmotic potential of solutions produced a decreasing of all seedling traits excepting radicle weight which was heavier at -1.2 MPa. It was possible to discriminate in a significant way, for drought tolerance in germination stage with osmotic potentials of -1.2 MPa. The cultivar Pioneer 3031 which was more tolerant than Himeca 95 and in early growth stages (with osmotic potentials of - 0.6 and -1.2 MPa) using big seeds, in relation to small see.