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Ardisia humilis is an excellent wild ornamental plant. For the purpose of fully utilization of this elite germplasm, the flowering biology and breeding system of this plant had been explored in this study. We conducted field investigation in the flowering phenology, flower-visiting insect and their visiting behaviors on A. humilis individuals introduced in homogeneous garden. Furthermore, pollen viability and stigma receptivity were detected by pollen germination in vitro and benzidine-hydrogen peroxide method, respectively. Combined with artificial pollination,the self-compatibility and the self-pollination of A. humilis were also analyzed in this study. The results were as follows: (1) The florescence of A. humilis was from mid-late May to early June, and the full flowering period was at the end of May. The flowering period of the population, single plant and single flower were approximately 25 d, 17-20 d and 1 d, respectively. (2) A. humilis developed protogynic bisexual flowers, the pistil ripened first with partial overlaps on mature stage of pistil and that of stamen, while stigma remained receptivity until 1 d after stamens fall. (3) With the out-crossing index (OCI) value of 4 and pollen / ovule value of 5.61×103, the breeding system of A. humilis was considered to be outcrossing with partial self-compatibility, and the pollinator insects were essential. (4) The seed set of natural pollination ranked the highest level (average 52.96%), followed by that of autogamy (52.29%) and of artificial-cross pollination (50.33%), with no significant differences among the three (P>0.05), but significantly higher than that of artificial geitonogamy (28.67%) (P<0.05). This study indicated that, beside of being excellent flowering plant, A. humilis was also a potentially important ornamental fruit plant due to the generalized pollination system and the strongly autogamy ability which enhancing the high success of fruits development from blossoms. (5) Lasioglossum sp. 1, Lasioglossum sp. 2 and Halictus sp. were the most observed floral visitors on Ardisia humilis. This study provides an important theoretical reference for the resource utilization and germplasm innovation of A. humilis. [ABSTRACT FROM AUTHOR]

Hopea chinensis is one of the representative tree species of tropical seasonal rainforests in China. It is an endangered and protected plant with beautiful tree shape and cold tolerance. To clarify its pollination biology, and breeding system and demonstrate its reproductive potential in Guilin, where this species was introduced for protection, we conducted the following experiments: the observation of flowering phenology, the measurement of floral size and scent, the estimation of the breeding system by out-crossing index(OCI), the pollen-ovule ratio(P/O), pollen viability and the stigma receptivity and self-pollination, the observation of pollinators and the test of their pollination effectiveness, the assessment of reproductive potential and pollination limitation by hand cross-pollination. The results were as follows:(1)The flowering season of H. chinensis in Guilin Botanical Garden is from the end of July to the end of September. It lasts about 60 d. An inflorescence flowers for about 12 d, and the anthesis of a single flower lasts about 3 d. The flowers begin opening from 17:00 to 18:45.(2)H. chinensis is not dichogamous but herkogamous with stigmas higher than anthers. The period of high pollen vigor and that of high stigma receptivity largely coincide.(3)The outcrossing index(OCI)was four and pollen/ovule ratio(P/O)was 10 788±984.(4)Neither flowers self-pollinated nor thoses bagged all the tome set any fruitse, fruit set did not differ significantly between natural pollination and hand cross-pollination.(5)Fungus gnats were the only flower visitor to the H. chinensis in Guilin Botanical Garden and flowers set no fruits with fungus gnat excluded.(6)The floral scent is dominated by β-elemene,(E)-7,11-dimethyl-3-methylene-1,6,10-dodecatriene and 1-caryophyllene. In conclusion, H. chinensis breeding system is self-incompatible, and it relies on fungus gnats for fruit production. It can set fruits and produce mature seeds in Guilin. The results can promote the protection and propagation of H. chinensis. [ABSTRACT FROM AUTHOR]