Reproductive Ecological Characteristics And Genetic Diversity AFLP Analysis Of Rare Eremophyte Helianthemum Soongoricum

In this paper, at the core and marginal area of the West Ordos Nature Reserve Park, the rare eremophyte shrub species of Helianthemum soongoricum Schrenk was studied as the target species, which was systematically conducted on the reproductive characteristics, the reproductive law and the reproductive adaptive countermeasure from three levels of the individual, population, molecular based on the observation on the sample plants in the fixed plots and the experimental analysis indoor. And it involves some principles and methods from many subjects and disciplines, such as reproductive ecology, population ecology, reproductive biology and conservation biology and so on.The long-term timed, plant-fixed observations were conducted based on the selected plots in this study. The pollen germination and pollen-ovule ratio (P/O) of Helianthemum soongoricum were experimentally measured indoor. With the means of quantitatively measurement outdoor, experimentally measurements and the mathematically analysis, the reproductive phonological law, distribution characteristics and ecological environment of H. soongoricum population were explored. On that basis, the breeding system, sexual reproduction process and its reproductive characteristics of the H. soongoricum were studied, the reproductive age and age structure of H. soongoricum population were measured, the Reproductive Value Table were worked out, the temporal and spatial reproductive allocation of H. soongoricum population were studied. Finally, the reproductive adaptive countermeasures of H. soongoricum population were analyzed.The research results show that:1) Helianthemum soongoricum are continuously flowering and fruiting during each growth season, which are closely related to precipitation,.its flowering rate in May and August with more precipitation was significantly higher than that in other months。2) Throuth the pollen-ovule ratio(P/O) and OCI and the emasculation, the breeding system of Helianthemum soongoricum was determined as outcrossing chiefly and self-compatible partly. And so pollinators are required during the pollination process, there is no apomixes. The floral traits presents the difference in different times, which the morphological characteristics of its flower reached the maximum value in May and in August,the two flourishing flower stages,but it is similar in different slop position.3) For the Helianthemum. soongoricum population, although a large number of buds and flowers were produced in the whole growth cycle, the mature seeds were relatively few. So its reproductive efficiency is low. Both of the theoretical present reproductive value and actual present reproductive value present the relative difference for the different phase, which they are higher in breeding season than in other times. The reproductive value of the H. soongoricum population in different slope position was significantly different, which present that in the upper slope position is greater than that in the middle slope position where it is greater than that in the lower slope as a whole;4) The reproductive fecundity and reproductive value of Helianthemum soongoricum increase firstly and decrease succedently with the increasing of its ground diameter. The reproductive value of the plants in the middle and lower slope position reaches the maximum in 18 ~ 21mm ground diameter grade, but that in the upper slope position does in the 15 ~ 18mm grade. Individual in the upper slop position have the largest reproductive value, followed by that in the lower slope and middle slope position. Residual Reproductive Value (RRV) of the population in different slope positions presents decreasing trend. Summed Residual Reproductive Value (SRRV) decreases with the ground diameter grade increases. Total Reproductive Value (TRV) of the population in the upper and lower slope position increasing firstly, subsequently decrease, but that in the middle slope position is instable. The Reproductive strategy (ORE) of the population in the upper slope position is highest, that in the lower slope is the minimum;5) Reproductive allocation of Helianthemum soongoricum population is different in the different reproductive stage. But in the different reproductive periods, reproductive allocation of H. soongoricum populations presents the trends of high-low-high-low; the reproductive allocation in different slope position is that in the upper slope is higher than that in the middle slope followed by that in the lower slope. The greater of H. soongoricum plant volume is, the higher of the absolute reproductive investment, but the lower of the relative reproductive allocation. Conversely the reproductive allocation of small individuals is higher;6) The genomic DNA of Helianthemum soongoricum was extracted by 2×CTAB;After systematically study on the main factors involved,an AFLP silver-staining analysis system suitable for H. soongoricum was established.The purified genomic DNA450ng,EcoRl and Msel were in a reaction volume for incubated at 37℃for 5h.and restriction at 4℃overnight.The pre-amplified produce was also diluted 10 time with TE buffer andused for selective amplification;Seven EcoRl/Msel primer pairs showing high level of polymorphism and scorable strong band were selected out from 64 primer combinations and used for further practical AFLP analysis.1512 bands were scored,44.44%of which were polymorphic;As analyzed by NTSYSpc2.11F,the similarity coefficient of 30 H. soongoricum cultivars ranged from 0.36 to0.70. UPGMA cluster analysis showed that 20 in the tested materials could be divided into four groups when the simple matching coefficient is 0.59. The aim of this paper was to lay foundation for the research of varieties classification and genetic relationship.7) Helianthemum soongoricum population distributed in a narrow region, and the population density is low, which presents the endangered species characteristics. In the whole life history, many factors, such as poor seed maturity, low seedling survival rate and human activities and so on, aggravate the endangered level of H. soongoricum. Both of the internal factors and external environmental conditions faced by the H. soongoricum population affect its living.