The Study On Rust Occurrence And Resistance Of Genetic Resources Of Zoysia Willd.

Zoysia Willd. is an acknowledged excellent turfgrass over the world, which is used widly in China, Japan, Korea and transition band of America. Rust is a main disease on Zoysia Willd., it can destroy lawn sight and uredinia stain shoes and clothes of individuals walking on zoysia rust affected turf, even made people hypersusceptibility. Pesticide is used to control rust on turfgrass regularly at present, but this measure is not only bad to people's health, but also pollutes environment. It is very important to evaluate rust resistance of Zoysia Willd. exactly, for selecting rust resistance variety and turfgrass rust control.For the moment, there is a few reports about rust of Zoysia Willd. at domestic and abroad.In China, there are just some reports about rust on Zoysia tenuifolia Willd. and Zoysia matrella (L.) Merr.. In order to breed excellent Zoysia Willd., and control the rust on the turf established with Zoysia grass. Studies on identifying pathogen of rust on Zoysia Willd., investigating pathogeny regularity and the influence of cross-breed and mutagenize on rust resistance improvement , the influence of clipping on rust control, and comparing with two assessment methods for rust resistence.The main results shows as followings: 1. Identification of the rust pathogen and its occurring on Zoysia Willd.The rust pathogen collected from twenty-one samples of three species of Zoysia Willd. in Nanjing during 2004～2005 were surveyed and identified. The result showed that the rust pathogen were Puccinia zoysiae Dietel, and put forward some measures on disease control based on pathogen characteristic.The period of pathogeny of 142 samples of Zoysia Willd. were investigated, the results showed that: the variantion ranges of the period of pathogeny on interspecies are great, the period of both uredinispore and teliospore ranked as followed: Z. japonica>Z. sinica>Z. matrella>Z. tenuifolia, consisting to the area of distribution of Zoysia Willd.. Intraspecific uredinispore variation coefficient of Z. japonica, Z. sinica , Z. matrella and Z. tenuifolia were 100.44%, 120.21%, 140.17% and 110.17% respectively. Teliospore variation coefficient of Z. japonica and Z. sinica both were above 8%, higher than Z. matrella and Z. tenuifolia distinctly, which were 2.92% and 0.41% respectively.