tailieunhanh - Ecophysiology of the holoparasitic angiosperm Cistanche phelypaea (Orobancaceae) in a coastal salt marsh
Cistanche phelypaea (L.) Cout. (Orobancaceae) was found parasitising the roots of the succulent shrublets Arthrocnemum macrostachyum (Moric.) (Chenopodiaceae) in a coastal salt marsh in Qatar. Measurements were conducted to identify soil properties, host, and noninfected plants by soil excavations to expose the haustoria of the parasite attached to the host roots. | Turkish Journal of Botany Research Article Turk J Bot (2013) 37: 908-919 © TÜBİTAK doi: Ecophysiology of the holoparasitic angiosperm Cistanche phelypaea (Orobancaceae) in a coastal salt marsh Gamal Mohammad FAHMY* Department of Botany, Faculty of Science, University of Cairo, Giza, Egypt Received: Accepted: Published Online: Printed: Abstract: Cistanche phelypaea (L.) Cout. (Orobancaceae) was found parasitising the roots of the succulent shrublets Arthrocnemum macrostachyum (Moric.) (Chenopodiaceae) in a coastal salt marsh in Qatar. Measurements were conducted to identify soil properties, host, and noninfected plants by soil excavations to expose the haustoria of the parasite attached to the host roots. The water potential, osmotic potential, pressure potential, and chemical analyses were determined in parasite, host, and noninfected plants. Crown diameter and dry mass of the host plants were smaller than in the noninfected plants. A gradient of water potential existed between the host root and the underground tuberous body of the parasite. Potassium was the major cation found in the parasite, while sodium was dominant in the host and noninfected plants. The nitrogen, soluble sugars, total amino acids, and starch contents of the parasite were higher than those of the host and noninfected plants. The high ratio of K+ to Ca2+ in the parasite indicates that it is phloem-feeding. The high nutrient element contents and metabolic products in the parasite are possibly related to the creation of osmotic and water potential gradients between the host and C. phelypaea. Key words: Cistanche phelypaea, Arthrocnemum macrostachyum, water potential, osmotic potential, salt marsh, Qatar 1. Introduction About 1% of the flowering plants, approximately 4000 species in total, are parasitic (Press and Phoenix, 2005). These plants form a close connection with .
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