| Cenchrus pauciflorus Benth invaded in Northeast, Inner Mongolia of China, caused serious damage to local agricultural production and the ecological environment. In our reseach, we use molecular biology techniques, compared the two kinds of phenotypes C. pauciflorus(upright and creeping type) by ITS, rbc L, and trn H-psb A sequences, the results show that both of the plants are as 99% similar as C.echinatus, we believe that they are two highly relative species.In order to analyze the spread diffusion path of C. pauciflorus Benth, we divides the Northeast, Inner Mongolia region into 16 populations, using RAPD to analyze the diversity of each population. The results showed that, the invasion of Northeast, Inner Mongolia region has two main line, that is Linghai, Yixian, Zhangwu, Tongliao-Zuoyihouqi, Tongliao-Zuoyizhongqi; another one is Tongliao-Zuoyihouqi, Kailu country, Naimanqi, Chifeng-Aohanqi.C. pacaciflorus Benth is a destructive and invasive weed in pastures, and its burs can cause gastric damage to animals. The strong adaptability and reproductive potential of grassbur is partially due to a unique germination mechanism whereby twin seeds develop in a single bur – one seed germinates and another remains dormant. To investigate the molecular mechanism of seed germination in twin seeds, we used isobaric tags for relative and absolute quantitation(i TRAQ) to perform a dynamic proteomic analysis of germination and dormancy. A total of 1,984 proteins were identified, and 161 of these were considered to be differentially expressed. The differentially expressed proteins included 102 up-regulated and 59 down-regulated proteins. These proteins were grouped into seven functional categories, and ribosomal proteins were the predominant group. The authenticity and accuracy of the results were confirmed by ELISA and q PCR. A dynamic proteomic analysis revealed that the insulin signaling pathway modulates ribosome synthesis and carbohydrate metabolism to promote seed germination. Treatment of seed with exogenous insulin demonstrated that insulin can suppress dormancy and promote germination in twin grassbur seeds. Together, the results showed that insulin is a key molecular signal that stimulates seed germination in grassbur by modulating ribosomal synthesis and carbohydrate metabolism.C. pacaciflorus Benth propagates by seeds, the composition and characteristics of its seed bank have a greater impact on prevention. In our study, the amount of Cenchrus pacaciflorus Benth seeds in the soils of natural grassland and farmland was measured; the effects of fertilization, irrigation, plant-mowing and using replacement plant species on C. pacaciflorus were analyzed. The number of seeds of C. pauciflorus reached 12923/ m2 in natural pasture soils and 8960/ m2 in upland farming soils, which was 67.72% and 79.74% of the total seeds, respectively, from the two types of soils. In natural grassland, the seeds of C. pauciflorus were mainly distributed on the top 0-2.0 cm layer of soild, being 45.71% of the total seeds. In farmland soils, however, the numbers of C. pauciflorus seeds were not significantly different on the 0-2.0 cm, 2.0-5.0cm and 5.0-10.0 cm layers of soild(p>0.05). Experiments showed that seed production was increased significantly at the low-dosage of fertilizer application(p<0.05), but it was much lowered at the intermediate and high dosages of fertilizer treatment. The seed yield of C. pauciflorus was related positively to the amount of water application in irrigation and it was 2562.8 seeds per plant. Plant-mowing suppressed seeds production of the weed and a reduction of 97.69% of seeds was observed by mowing the weed once a week. Planting sunflower(Helianthus annus L.) and Jerusalem artichoke(Helianthus tuberosus L.) suppressed the growth and seed yield of C. pacaciflorus plants very significantly(p<0.01). |
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