The Clone Growth Characters And Its Hyperparasitism On Rust Of Hedysarum Scoparium

Distributing patern of soil properties, including soil moisture and nutrients beneath the shrubs of Hedysarum scoparium and its ecological adaptability of clonal traits to sandy habitats in Wulanbuhe desert were studied using field experiments. We also identified the pathogeny and researched the biological characters of its hyperparasitism. The results are as following:1.The soil nutrients, such as organic mater, total N, available K and hydrolytic N, and the soil moisture under the shrubs of H. scoparium were heterogeneously distributed. It has shown an evident phenomenon, called "island of fertility" in the shrubs because there were high content of medium-fine soil parfcles(0.25～0.02mm) and relatively abundant soil moisture, organic mater, total N, available K and hydrolytic N on the soil surface under the shrubs, and furthermore, the content of soil moisture and nutrients gradually decreased from the center of the shrubs to its edge in this soil layer.2.Hedysarum scoparium has special patterns of clone growth:the guerrilla pattern,which is made up of long dropping branch was covered by sands;the phalanx patterns,which composed of roots.Comparing with the ramet population in the semi-fixed dunes,the ramet population in the fixed dunes exhibited higher ramet density and smaller average ramet spacing.They had similar ramet height3.The pathogeny of Hedysarum scoparium rust is Uromyces onobrychidis (Desm.)Lév. and the hyperparasite is Sphaerellopsis sp.. The optimum growth temperature for Sphaerellopsis sp.was 15~25℃. After 10 days of at a temperature of 20℃on PDA,conidia were formed,after 12 days,yellow white spore horn was also produced.There were 4 kinds of carbon sources including glu-cose,mannitol,starch and maltase were optimum.The relative humidity for spore germination were 70%~98%,but best in drops of water.The scatter light was better for the spore germination.Among nitrogen sources, sodium nitrate, glycine and peptone were better for mycelia growth .the spore formation was better on asparagines, peptone and, no spore was produced on glycine.