Breeding System Comparison Of Three Speeies Of Eremurus Based On The Scale Of Their Populations

In this paper, we observed the flowering phonology, characteristics of breeding system, flower morphology characteristics, pollination ecology and the difference of seeds of three species of Eremurus based on scale of their populations. The main rusults were as follows:1. The difference of flowering phenology among different populations and inter-specfic. The early flowering stage of E. anisopterus and E. inderiensis among different populations were delayed 2-3 days from west to east. The whole flowering period of inter-specfic of E. anisopterus and E. inderiensis were no significant, which was about 20 days. The flowering period of E. altaicus among different populations were very significant, The early flowering stage of the lower altitude population was very earlier and the whole flowering period lasted very shorter; The early flowering stage of the higher altitude population was delayed about 30 days, and the whole flowering period was more than 9 days with the lower altitude population, which indicates that it adapted highly to different habitats.2. Pollen vitality of E. anisopterus and E. inderiensis among different populations were up to 95% on average, which was the lower in the environment of pollution. The different populations pollen vitality of E.altaicus were about 85% in high-altitude, low-temperature. According to Cruden's P/O judegment, the P/O of three speeies of Eremurus is obligate xenogamy, but artificial isolation experiment could also produce seed, which indicates that they are self-compatible. The mixed breeding system of three speeies of Eremurus is a kind of compromised mechanism which adapts to the environmental condition and plant themselves.3. There were highly significant with the single flower floral display of inter-specfic. The 6 tepals of E. anisopterus are outspread thoroughly. The lower 3 tepals are just like a platform for visitors, the 6 anthers start to disperse one by one, the stigma style (upwards curve at anterior part) increases the chance that it accepts pollens from the anther in the same flower and from the body of insects. In the desert with high daily temperatures, the umbrella-formed by the upper 3 tepals form a so-called awning for visitors. While the 6 tepals of E. inderiensis are not outspread, and the 6 anthers come out the tepal one by one, and then the stigma style come out the tepal. The stigma style of E.altaicus is upward at first(upward 1st stage), when the 6 tepals completely wrapp ovary, the stigma style is downward (downward stage), and the anther start to disperse one by one. When the six anthers are bare, the stigma style is upward again(upward 2nd stage).4. Heterotypical maturation of stamina of three speeies of Eremurus significantly prolonged the pollen-dispersion period of a single flower. The duration of pollen dispersion among different populations are no significant, but inter-specfic are very significant.The single anther pollen- dispersion period of E. anisopterus was about 40 min. Compared with E. anisopterus, Pollen- dispersion period of E. inderiensis and E.altaicus respectively are 1.5 times and 1.75 times.5. The main pollinators of three speeies of Eremurus belongs to Apidae,Megachilidae, Halictidae, Syrphidae, Sarcrophagidae, Bombyliidae, Therevidae. We considered that the tepals of three speeies of Eremurus play the most important rule for the pollinators and pollination. Pollinators among different populations and inter-specfic are very significant.6. Stigma receptivity of three speeies of Eremurus are significant. Four hours after blooming, stigma receptivity of E. anisopterus reaches to the summit, and stigma receptivity of E. inderiensis and E.altaicus respectively are 1 d and 2d after blooming. Thousand seed weigh of E.altaicus among different populations was significant, and thousand seed weigh of E. anisopterus and E. inderiensis among different populations was no significant. Comparison with inter-specfic, E. anisopterus >E. inderiensis>E.altaicus.