| Alfalfa (MedicagosativaLinna)high-qualified forage in the development of animal husbandry in the world. it occupies a very important position. In recent years, with the increasing in acreage, alfalfa disease is becoming more and more serious. It has become a major restricting factor for alfalfa’s yield and quality. Alfalfa Alfalfa leaf spot by the false sclerotiorum (Pseudopeziza medicaginis) is one of the main diseases caused for productional alfalfa, it happens among major growing areas in varying degrees. As a result, selecting the appropriate method to controll its damage is significant important. In this paper, we focus onLiupan alfalfa leaf spot and its damages affecting on the nutritional quality of alfalfa leaf spot, ascospore germination characteristics and secretion of cell wall degrading enzyme activity. The results are as follows:(1)Field survey results showed that:Guyuan, Jingyuan County, Longde alfalfa leaf spot incidence of serious disease index were 68.61,30.01,75.81.(2)Different levels of alfalfa leaf spot incidence of leaf, stem the nutrient content of the test shows that: With the increasing in the degree of susceptibility, alfalfa crude protein (CP), crude fat, K content decreased; neutral detergent fiber (NDF), acid detergent fiber (ADF), crude ash, Ca, total phenols, tannin content increased; P content did not change. Among them, compared with healthy blade, IV grade sense of diseased leaves Tablets CP, the content decreased by 15.64%, the content of NDF, ADF increased by 39.75%,71.10%, this indicats that the nutritional content of alfalfa after susceptible severely is damaged. Diseased leaves the film a sense of chlorophyll a, chlorophyll b decreased by 18.02%,70.25%, an increase of 42.31% carotenoids, indicats that alfalfa Pseudopeziza can damage the photosynthetic mechanism of the blade, disrupt the normal light capture capability, and this is a mein factor which causes leaf senescence.(3) The result about P.medicaginis ascospores carbon and nitrogen sources using experimental show that: the testing five carbon sources, the utilization of carbon from strong to weak as glucose, maltose, sucrose, lactose, and glycerol, ascospores germination time to focus on 4 -9h. Tested nine nitrogen sources, organic nitrogen source, yeast extract, beef extract, peptone ascospores germination time to concentrate on 5-13h,72h germination rate of 100%. Inorganic nitrogen and ammonium oxaloacetate germination rate consistent with the control agar; amino acid and sodium nitrate 7-9h you can see there are ascospore germination,72h germination rate of 100%. Description alfalfa Pseudopeziza source of carbon and nitrogen nutrition requirements are not strict, more widely, but use varying degrees(4) The result about P. medicaginis ascospore germination of Ca2+/CaM signalyse show that:exogenous CaCl2 with the concentration of 0.1-100mmol/Lascospores may germinate added Ca2+ chelator EGTA inhibited germination, while adding EGTA(10mmol/L) and CaCl2 (lmmol/L) can not neither relieve the inhibition, but added EGTA(10mmol/L) in the vector A23187 (10μmol/L), ascospore germination rate was significantly increased. PLC inhibitors Neomycin eith a concentration of 0.01-10mmol/L, ascospores not germinate. Ca2+ channel modulators Nicardipine concentration of lmmol/L, the ascospores are dissolved at other concentrations not germinate. CAM antagonist Chloropromazine concentration of O.Olmmol/L, no ascospore germination and around floe surrounded concentration is greater than 0.1mmol/L also inhibited germination.(5) The result of P.medicaginis secretion of cell wall degrading enzymes and sense cell membrane permeability measurement test shows that the diseasing blades:ascospore secreted methyl pectin galacturonic acid enzyme (PMG) as the main cell wall degrading enzymes, as the culture time prolonged PMG, carboxymethyl cellulose Luciferase activity enhancement, (3-glucosidase activity is small and did not change significantly. P.medicaginis ascospore infection Alfalfa Leaves of host cell membrane permeability serious injury break, with the extension of time of infection, membrane permeability enhancement,72h reached the maximum point of 40.90%. |
PDF Full Text Request