Santalum album: kernel composition, morphological and nutrient characteristics of pre-parasitic seedlings under various nutrient regimes
1997
Barrett, D.R. | Fox, J.E.D.
Omission of all nutrients or individual minerals (N, K, P, S, Ca) from the growth medium of pre-parasitic Santalum album seedlings produced significant morphological effects. Compared with fully fertilized seedlings, shoot and root length, leaf area, leaf length and width, leaf number, internode length, shoot length/root length ratio, chlorophyll levels, fresh mass and dry mass were all reduced; leaf thickness increased and stomatal numbers, petiole lengths, root lengths and haustorial numbers showed variable but significant responses. Mineral-specific deficiency symptoms were evident in all omission treatments after 3 months. Treatments in which N, K or all minerals were omitted had the greatest dwarfing effect and increase in height and leaf number ceased after 3 months: only seedlings with no added nutrients (dependent on kernel nutrition) were healthy. The mineral content of no-nutrient seedlings approximated that in kernels. The distribution of minerals between plant parts for each treatment is given. K concentrations and K/Ca ratios were relatively high in leaves of seedlings which received treatments containing K, especially when Ca was absent. A high K/Ca ratio may be inherent in S. album seedlings rather than acquired after subsequent host connection. All fully fertilized seedlings developed haustoria within 3 months suggesting readiness for early host attachment. Seedlings in no-nutrient, no-N, no-K or no-P treatments had fewer haustoria.
显示更多 [+] 显示较少 [-]