The Primary Study Of The Growth Characteristics Of Sunflower Influened By Sunflower Wilt And Its Inductor

Sunflower Yellow wilt disease is a devastating disease infected by Verticillium dahliae Kleb., at present. Occurrence regularity and control technique of Sunflower Yellow wilt disease, little research both at home and abroad, noly only the control effect of the zero tillage,crop rotation, and verticillium wilt resistant varieties is cleared. So, this experiment is focus on the growth and yield of sunflower influenced by the infected periods and severe disease index of sunflowers by verticillium dahliae, and desease induced resistance. The specific research results are as follows:1. In order to clarify the effects of different infected periods of Verticillium dahliae on the growing condition and yield of sunflower. LD5009 were planted in the artificial nursery for the Sunflower Yellow Wilt in Innermongolia Agricultural Univeristy Farm. the disease index were calculated with the labelled plants showing the typical symptoms of different scales of yellow wilt in the seedling, flowering and mature stage. The growth and yield parameters such as the height of plantand the diameter of stem and flower disk, the hundred-grain weight, the seed production rate and the oil content were measured after being harvested. Our data indicated that the height of plants, the diameter of stem and flower disk, hundred-grain weight, the seed production rate and oil content of seeds were dramatically influenced by the infected periods of yellow wilt disease. The earlier infection, the more severe disease index and vice versa.2. LD5009 and 3638c were planted in the artificial nursery for the Sunflower Yellow Wilt, The growth and yield parameters such as the height of plantand the diameter of stem and flower disk,the hundred-grain weight, the seed production rate and the oil content were measured after being harvested. Our data indicated that the height of plants, the diameter of stem and flower disk, hundred-grain weight, the seed production rate and oil content of seeds were dramatically influenced by the disease grade.3. We studied on the induced resistance of seven inducers such as K2HPO4, salicylic acid, Chitin, sodium silicate, oxalic acid, BTH, glucan. In order to provide evidence for the prevention of sunflower Yellow wilt disease, induced-resistance. It explains that the K2HPO4, Chitin, sodium silicate, glucan in the concentration range do not inhibit direct effects on V.dahliae mycelium.and the 200mg/L oxalic acid have inhibit effects on V.dahliae mycelium. The text of screening of V.dahliae inducer,which showed that only two kinds, sodium silicate and oxalic acid could induce the Sunflower Yellow wilt disease. We do some further studies on the sodium silicate and oxalic acid’s physiological mechanism of V.dahliae. All SOD, POD, CAT, PPO activity shows a rising trend with induction-inoculation treatment, and even higher than that of control. Prove that induced resistance agent may play a role in blocking pathogen intrusion.4. The disease incidence and disease indices of the treatment inoculated with H2 alone were significantly higher than those of the treatments inoculated with BM-1 (Verticillium nigrescens Pethybr.) or H63(Verticillium dahliae Kleb.) alone, which indicated that compared with V. dahliae isolate BM-1 and H63 were weakly pathogenic or non-pathogenic to sunflowers. When plants of both sunflower varieties (LD5009 and3638C) inoculated with BM-1 or H634 days prior to inoculation with H2(Verticillium dahliae Kleb.), the disease incidence and disease severity indices were evidently lower than those of the plants inoculated with the virulent isolate H2 alone.And We do some further studies on the BM-1 and H63’s physiological mechanism of V.dahliae. The sunflower inoculated with BM-1 or H634 days prior to inoculation with H2, all SOD, POD, CAT, PPO activity shows a rising trend than that of control, suggesting that BM-1 and H63 may protect sunflower against V. dahliae.