Seed Size and Oil Content Are Key Determinants of Seedling Vigor in Gossypium hirsutum

Abstract

Despite the plethora of information on seed characteristics and seedling vigor in cotton, the near-continuous release of new cultivars coupled with limited information on seedling vigor for field conditions necessitates re-evaluation of seed characteristics important for vigorous seedling growth and plant establishment. Consequently, seedling vigor (fresh weight at the 2 to 3 leaf stage) and stand establishment were evaluated for 11 cotton cultivars across five locations in Georgia during the 2012 growing season. Seed size, seed oil content, and seed protein content were also evaluated for each cultivar. Cultivar differences in seedling vigor existed under field conditions for the genotypes evaluated. Genotypic correlations and regression analysis revealed a negative relationship between oil (%) and protein contents for quiescent seeds (r2 = 0.945). Additionally, positive relationships were observed between seedling vigor and total seed oil content (r2 = 0.573), and seedling vigor and seed size (r2 = 0.642). Cultivar differences existed in germination responses to incubation time and temperature, but these responses were not necessarily predictive of seedling vigor. These data indicate that information on seed oil content and seed size could help identify cultivars or seed sources with potential for high seedling vigor for use in production scenarios where reduced seedling vigor may limit productivity.