Systematic Research Of Homegrown Conyza Less

Conyza Less.which belongs to Aster, about100species, distributed mainly in eastern, the tropical and subtropical areas of the western hemisphere, our country has10,2varieties, and distributed in the south and southwest. C. Blinii levl., c.muliensis Y. L. Chen, and C. Perensis Hand-Mazz. for endemic to China, only in sichuan, yunnan and guizhou in distribution; C. Canadensis (L.) Cronq. And other two species introduced from north amerrica for modern.Species such as the spread of weeds is C.chilensis C.Spreng. At present, very little for liquor grass genus, only a small number of scholars in chemical plants, reproductive ecology and other aspects have been explored.In this study, seven Conyza species of the bear bile and grass morphology, cytology, molecular biology research, aimed to ascertain whether the domestic Conyza and North America, the incoming Conyza are monophyletic, domestic Conyza the origin and evolution path, the relationship between the domestic Conyza variety of what planted the authenticity of the variants.1. Macromorphological analysisBelong to Conyza Less,morphologic characters of many study found that the size of the leaves, inflorescence size, plant height of some vulnerable to environmental impact of traits couldn’t be used to distinguish the Conyza Less,between the evidence.Through the stomata size, number, the number of cells and form around is also didn’t find information of valueConyza is distinguished morphologically from Erigeron principally in reduction in ray floret ligule length and in a marked decrease in the number of hermaphroditic disc florets relative to female ray florets. In the greenhouse,isolated individuals of Conyza canadensis, C.bonariensis,and E.acris(E.sect.Trimorpha) produce high numbers of germinable seed.Reduction in length of ray floret ligules,which presumably function to attract pollinators,and proliferation in number of female florets also appear to be evolutionarily favorable in autogamous Conyzinae. Otherway Laennecia and Podocoma(Astereae),and Blumea and Pluchea(Inuleae), are also characterized by numerous ray and few disc florets.Many of these taxa share historical synonymy with Conyza.)2MorphologyWe study Conyza Less.number of chromosomes, which Conyza blinii Levl. And Conyza muliensis Y. L. Chen for the first time the chromosomes of the report. Conyza canadensis (L.) Cronq in foreign countries are2x or6x, but in our country are6x, also Conyza bonariensis (L.) Cronq foreign coverage diploid are2x or6x, we in the domestic acquisition of the many local Conyza bonariensis (L.) Cronq, through experiment found, are all6x.Combining both of the distribution of the weed is extensive, have extremely strong diffusion and survival ability, one of the differences may show that such a possible, plant in with unfamiliar environment, to take many times of the reproductive strategy, the other plants in compositae get confirm. This strategy can adapt to the more complex is the habitat, this may cause them to adapt to the new environment in the shape of the have more possible, such as synthetic related material, inhibit the growth of around species, the roots of the deeper, more tall plant and so on.3Molecular systematicsIn this study, the liquor grass is seven kinds and some Astereae species ribosomal DNA internal transcribed spacer region (ITS) PCR amplification, purification and sequencing, combined with information from GenBank, using Bayesian method and the strict consensusmethod to establish the molecular phylogenetic tree for the analysis of Conyza Less.location and other problems.The ITS data show that the Conyza Less.is polyphyletic. In the ITS phylogenetic tree, native to North America C. Canadensis and other two spices and Erigeron, Symphyotrichum and Solidago have1.00Bayesian trees support rate and95%the maximum parsimony method of MP tree support for the North American branch; the origin of China’s four Conyza Less.species belonging to the other two branches. This shows that (1) North American production of Conyza and domestic Conyza is not a close genetic relationship, domestic Conyza from the Conyza Less separated;(2) domestic Conyza Less.is not the the monophyly, C.japonica(Thunb.) Less.,C.muliensis Y. L. Chen and C.blinii Levl. to form a branch of the C.aegyptica (L.) Ait. and other African origin, Conyza plants, and Bayesian tree supports rates up to0.98, while the MP tree support was only69%. Energizer straight liquor grassland variants and feather crack fresh leaves straight Conyza constitute another branch Hypericum (Grangea maderaspatana), the fish-eye grass (Dichrocephala auriculata), the Bayesian tree support rate up to0.98, while the MP tree support for up to90%.Erigeron leptorhizon shares many morphological features with Conyza species(annual habit,reduced ray floret ligules,) and it is therefore not surprising that ITS shows that the two taxa are closely related.Because of the topology of this clade,it is impossible to determine progenitor and derivative status of the constituent taxa.lending further confusion as to the status and biogeography of Conyza。To summarize,JTS sequence data for Conyzinae are highly informative and yield cladograms that provide insight into a diversity of geographical,systematic,and evolutionary questions.The data strongly indicate that:1, domestic Conyza Less.can have three dissemination route, a originated in the northwest America, then spread to South America, Europe and Asia. Such as C.bonariensis, C.sumatrensis, C.canadensis. Another originated in Africa, and then spread to Asia, such as C.japonica(Thunb.) Less.,C.muliensis Y. L. Chen and C.blinii Levl. C.aegyptica (L.) Ait.The third way, C.stricta Willd. is originated in Asia tropics.2) Domestic Conyza Less. of molecules of grass sequence analysis shows that, North America and Africa Conyza all may not be uniparental groups, C.sumatrensis and C.bonariensis is a silk, C.canadensis more close to the Erigeron with Erigeron breviscapus a silk. Asian and African branch of C.japonica and C.blinii are same silk, C.muliensis and two from the same ancestor.3)long-distance dispersal,in part,can explain present distribution patterns.