Mineral Nutrition of Sandalwood (Santalum spicatum)
ABSTRACT Acacia acuminata is a preferred host of the root hemiparasitic tree, Santalum spicatum (sandalwood). Comparison between nutrient content of adult trees of sandalwood and results for an earlier study of the mistletoe, Amyema preissii , on the same host species, A. acuminata , showed similar high levels of K and Na and low levels of Zn in both parasites compared with the host plants. Differences in K, Ca, N and Cu levels between parasitized and uninfected Acacias imply that the host plant contributes to the nutrition of sandalwood. The high K/Ca ratio in sandalwood confirms that K uptake in preference to Ca is a general feature of all categories of angiosperm parasites. Patterns of distribution of nutrients between various parts of sandalwood and A. acuminata depend on the type of nutrient, but levels are usually highest in leaves of both species and the haustoria. Although K, Ca and Na are much lower in the kernels than in vegetative parts of the parasite, only seedlings without supplementary Ca in a nutrient omission experiment failed to grow at all in the absence of hosts. Growth is not dependent on the level of K in the unattached plants but other evidence indicates it may have a role in water uptake in the attached plant. Calcium supply has a marked effect on internal Ca levels and growth of unattached plants. Compared with field plants, levels of Ca, and to a lesser extent Zn, were much higher in plants of the Ca/K treatment that produced greatest growth over 34 weeks. Haustorial formation is enhanced by the presence of A. acuminata roots. However, competition for nutrients, especially Ca, from co-planted A. acuminata seedlings results in suppression of growth of young sandalwood compared with their growth in the absence of the host species.
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ABSTRACT: Growth, mineral accumulation and above-ground dry-matter partitioning were measured in three sub-Arctic annual facultative root hemiparasites, Rhinanthus minor L., Euphrasia frigida L. and Melampyrum sylvaticum L., growing either unattached or attached to a host plant. Attached plants were at least an order of magnitude taller than unattached plants, and individuals produced a total above-ground biomass up to three orders of magnitude greater than that produced by unattached plants. Attached plants produced a greater number of branches, leaves, buds, flowers and ripe seed capsules. Leaf size was greater in attached than unattached plants. For two species, Rhinanthus minor and Euphrasia frigida, the response of individuals attached to a legume was compared to the response of those attached to a grass. Stimulation of parasite growth was greater with a legume host than with a grass. The architecture of parasites on legume hosts differed greatly from those either on grasses or unattached, with those on legumes often having a considerably greater number of second order branches. Above-ground biomass partitioning was affected by attachment to a host, and was a function of host type. Unattached plants of all three species of parasite accumulated foliar element concentrations within the same order of magnitude as their hosts. Element concentrations in attached plants were sometimes, but not always, greater than those of their hosts. Element concentrations, especially N, were greatest in those parasites attached to a legume.New Phytologist 04/2006; 125(1):131 - 138. · 6.74 Impact Factor
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ABSTRACT: A factorial experiment investigated the effect of six pot host species treatments (Alternanthera nana,Sesbania formosa, Atalaya hemiglauca, Acacia hemignosta, Crotalaria retusa and no pot host), two Santalum album seedling age treatments (24 and 17 weeks at field establishment) and a supplementary nursery nutrition treatment (2×100 ml 5% Ca Wuxal®) on Sa. album survival and growth 287 days after field establishment. Significant variation exists between pot host species in increasing Sa. album survival and growth. Al. nana and Se. formosa pot host species significantly increased Sa. album survival, height and diameter. Sa. album survival, height and diameter was significantly better with supplementary nursery nutrition. Sa. album survival and height was significantly greater and pot host species survival was significantly poorer with older Sa. album seedlings. Older seedlings and supplementary nursery nutrition gave higher levels of Sa. album field survival and growth when parasitised to poor pot host species but not when parasitised to satisfactory pot host species.Forest Ecology and Management. 01/1998;
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ABSTRACT: Field establishment of the root hemi-parasite Santalum album L. under large-scale plantation conditions, until recently, has been largely unsuccessful. In this experiment, the growth of S. album seedlings grown with the herbaceous pot host Alternanthera nana R. Br. for 134, 109, 84, 60 and 35 days in a nursery container prior to field establishment was examined after 11, 16 and 23 weeks in the field. S. album survival and growth was greater, and root:shoot ratio was lower for the 23 weeks for S. album seedlings grown with A. nana compared with seedlings grown without a host. Seedlings grown with A. nana for 134 days in the nursery prior to field establishment had greater stem diameter, height and root, shoot and total plant dry weight (DW) over the 23 weeks in the field than all other treatments. Seedlings grown with A. nana for 109 days in the nursery prior to field establishment had greater field survival than all other treatments. A. nana survival in the field remained high when grown with S. album for 134 and 109 days in the nursery prior to field establishment whereas survival within remaining treatments declined significantly and A. nana growth was significantly less. S. album grown with A. nana for 134 days in the nursery prior to field establishment had a lower root:shoot ratio than all other treatments at all assessments. A strong negative linear relationship exists between S. album root:shoot ratio and A. nana DW, whereas a positive linear relationship exists between S. album DW and A. nana DW. Foliar phosphorus and sodium concentrations for S. album were lower and foliar potassium concentration higher when seedlings were grown with A. nana for 134 days in the nursery prior to field establishment compared with the remaining treatments at the 16-week assessment. The period of the S. album:A. nana association in the nursery significantly influenced S. album survival and growth following field planting.Forest Ecology and Management - FOREST ECOL MANAGE. 01/1998; 111(2):107-118.