Artemsia Annua L. Induction Seeds Germination Of Sunflower Broomrape And Egyptian Broomrape

As an annual root parasitic weed, Orobanche and Phelipanche parasitism in the roots of host crop and causes massive yield losses crop production. In China, the place where plants sunflower was seriously infected by sunflower broomrape(Orobanche cumana), tomato and melon crops was also seriously infected by Egpytian broomrape(Phelipanche aegyptiaca). It is reported that biological control and “trap crop” or “catch crop” are potential methods to control broomrapes. Therefore, we have used 69 Chinese herbal from Qinghai-Tibet to induce germination of Orobanche and Phelipanche seeds in order to find suitable plants. The main conclusions of this study are as follows:1. By using distilled water and methanol extracts, 69 Chinese traditional medicinal herbs from the Qinghai-Tibet region were screened. The results displayed that: 1) of all the test materials, 16 herbs could induce Egpytian broomrape seeds germination(≥20%), 21 herbs were able to induce germination of sunflower broomrape seeds(≥20%); 2) Artemisia annua, Meconopsis racemosa, Kadsura interior, Dracocephalum ruyschiana, Nardostachys chinensis and Lamiophlomis rotata could induce both sunflower broomrape and Egpytian broomrape seeds to germinate(>20%), indicating that these herbs contained germination stimulatent(s) for broomrapes seeds to germinate.2. The extracts(methanol and distilled water) of Artemisia annua L. could induce broomrapes seeds germination, and there was a significant difference of germination rate among various organs during the whole growth stage. Two kinds of broomrape seeds germination rate which induced by roots were high during the whole growth; sunflower broomrape seeds germination rate induced by stems were higher at leave flourish stage, Egpytian broomrape seeds germination rate induced by stems was higher at flowring stage; Egpytian broomrape seeds germination rate induced by leaves was higher in the early nutritional growth stage. At seedlings, sunflower broomrape seeds germination rate induced by dried extract samples was higher than the fresh sample,but the opposite performance of Egpytian broomrape seeds. The two kinds of broomrape germination rates incude by rhizosphere soil extracts was below 20.0%,which showed that the germination stimulant secreted from Artemisia annua L. to soil could induce broomrape seeds germination at certain concentration.3. Substance inducing broomrape seeds germination in dry Artemisia annua L. sample could be extracted completely for 5 times by methanol extraction. Inducing substance can be extracted completely for 5 times by ethyl acetate: distilled water = 1:1 after methanol was evaporated to dryness. After ethyl acetate was evaporated to dryness, the residue was dissolved in acetone and made of crude extracts of Artemisia annua L..Column chromatography test of dry Artemisia annua L. crude extracts with 80% methanol concentration as eluent, germination rate trends of broomrapes seeds was manifested in inconsistency, and they all had rather than a peak value. Solutions which induced more than 10% seeds germination of sunflower broomrape or Egyptian broomrape were collected, extracted with ethyl acetate and dried with rotary evaporator in vacuum. The dry residue was redissolved with acetone and added to thin layer plates which were then spread with different developing solvents. Results showed that when the ratio of ethyl acetate to ether in the developing solvent was 1: 9, the separation effect was better for materials induced seeds germination of sunflower broomrape. And for materials induced seeds germination of Egyptian broomrape, when the ratio of ethyl acetate to chloroform in the developing solvent was 1:1, the separation effect was better than others. Through these experiments above we can find out that there should be several kinds or groups of germination stimulant of broomrapes seeds in Artemisia annua L..