Lower seed P content does not affect early growth in chickpea, provided starter P fertiliser is supplied

Abstract

Seeds of crops contain large amounts of phosphorus (P), mostly as phytate. To lower seed phytate concentration is the ultimate breeding aim and highly desirable as the benefit of humans and many animals, given seed size is not sacrificed, i.e. leading to reduced seed P content. This study tested whether low seed P content affects early chickpea growth, and whether P supply during early growth compensates for early growth from seeds with low seed P content. Twenty-three chickpea genotypes with contrasting seed P content were selected for three treatments that were compared with a control: 1) seedlings supplied with a small amount of starter P (P10), 2) one cotyledon removed to reduce P content (Remove 1), and 3) both cotyledons removed to further reduce P content (Remove 2). Genotypes with higher seed P content had more vigorous early growth than genotypes with lower seed P, as did intact seedlings compared with those cotyledons removed. Application of P fertiliser significantly enhanced early growth. Low seed P genotypes had a more economic strategy, with a greater specific leaf area and specific root length, than genotypes with medium or high seed P content. Our results provided useful information for breeders that breeding chickpea genotypes with reduced seed P, does not affect germination and seedling vigour, provided starter P is supplied at the early development stage.