| As one of worldwide main diseases of wheat, the stripe rust that broke out several times in China brought about a heavy loss. To reduce the harm from stripe rust, scientific and technological workers have carried on a large amount of research, however, which is focused on resistant varieties selection and chemical controls, rather than pathogens; and, hitherto, races identification is still dependent on host plants. In this study, to illustrate the physiological race diversity of wheat stripe rust pathogens, microstructure and ultra-microstructure of current prevailing, main physiological races were both observed; meanwhile, by using wheat variety mingxian169, physiological race of stripe rust shui4, and stripe-mixed bacteria as materials, activity changes of chitinase andβ-1,3-glucanase were researched respectively when wheat has been infected, in order to provide reference for wheat stripe rust pathogen's ultra-microstructure research on physiological races, morphological difference of physiological races, as well as pathogen controls. The results are as follows:1. Microstructure difference of main epidemic races. Urediospores of physiological races such as Tiao32,Shuiyuan4,Shuiyuan14,Shuiyuan7,HY8 were inoculated into glucose(0.3g) medium separately, then stored in the refrigerator(4℃). After fluorescent stain at different times(8th h,12th h,24th h), both of urediospore's germination and relevant vitro binding phenomenon were proceeded. Consequently, it was discovered that, having been treated by fluorescent dye DAPI, nuclear of mature urediospores showed light blue under the microscope(x100). After a 24h long culturing to these 5 urediospores of studied races, most of which are bi-nucleated, except cy32 the germ tube fusion could be behaved obviously by HY8,shui4,shui7 and shui14.2. Ultra-microstructure difference of main epidemic races. By means of sem (x100), these 5 urediospores of studied races all appeared a better protoplasm gloss and a mass of fat-granule aggregation. The cells are spherical or ovoid, in which two nuclear was situated closely to each other; there are plenty of cone-shaped spikes on the wall of urediospore. The difference of physiological races leads to inconsistent intension and various sags of spikes.3. Activity changes of chitinase andβ-1, 3-glucanase. In a 10 days long period after wheat seeding inoculation, activity changes of chitinase andβ-1, 3-glucanase in total enzyme fluids, intercellular washing fluids, and intracellular fluids of leaves inside were measured severally with spectrophotometer. According to activity change of total enzyme fluids, in contrast to the un-inoculated, Mingxian169-mixed combination's chitinase became more active than Mingxian169-Water4 combination's at 2dpi; whereas, at 4dpi, it turned less active while the Mingxian169-Water4 combination's rise sharply that it went more active than Mingxian169-mixed combination's chitinase. Afterwards, at 6pdi, the leaves-inside enzyme activity of Mingxian169-Water4 combination declined again, equaling to the contrast; meanwhile, the counterpart of Mingxian169-mixed combination emerged the peak. Theβ-1, 3-glucanase activity of Mingxian169-mixed combination went up steadily during 1-10dpi but fell down gradually after reaching the peak at 2pdi. The enzyme activity of Mingxian169-Water4 combination jumped up readily and climbed up to the top at 10pdi. Chitinase in intercellular washing fluids of Mingxian169-mixed combination was more active than Mingxian169-Water4 combination's, nevertheless,β-1, 3-glucanase of Mingxian169-Water4 combination acted more lively than Mingxian169-mixed combination's at 4pid, moreover, which seldom lasted, later, went back to be less active than Mingxian169-mixed combination's again; comparatively, in the light of what can be demonstrated from endo-cellularβ-1, 3-glucanase activity in leaves of Mingxian169-mixed combination, the enzyme activity of Mingxian169-Water4 combination is higher than Mingxian169-mixed combination's.
|
PDF Full Text Request