Mineral Nutrient Composition of Leaves and Fruits of Selected Species of Grevillea From Southwestern Australia, With Special Reference to Grevillea leucopteris Meissn

Abstract

A study was made of mineral nutrient concentrations and distributions in leaves and fruits of 10 species of Grevillea from diverse localities in south-western Australia. Seeds of all species contained high concentrations of mineral nutrients, despite the nutrient-poor soils of their habitats. Leaves and the leathery follicles which contained the seeds typically had very low levels of nutrients. With few exceptions, the concentration and distribution patterns of a particular nutrient in fruits were similar in all the species studied. In these species, over 90% of the P content, and between 50 and 70% of the N, Zn and Cu contents of a fruit were located in seeds. Some species accumulated very high concentrations of a particular nutrient, e.g. Ca in seeds and leaves of G. leucopteris, K in seeds of G. tripartita and Fe in follicles of G. petrophiloides. Ratios of K : Ca concentrations were low (< 1) in seeds of G. candelabroides, G. petrophiloides, G. pinaster and especially G. polybotrya and G. leucopteris, which are characterized by high Ca concentrations in their seeds. In the Grevillea species studied, Na C1 and Fe accumulated in the leathery follicle but not in the seeds.

A study of G. leucopteris from 18 localities throughout its ecological and distributional range showed that concentrations and distribution patterns for each nutrient in fruits were similar, irrespective of soil type. It is concluded from the results for G. leucopteris and the other species that there is conservative genetic regulation of seed mineral nutrition in the genus Grevillea.