The Study Of Reproductive Strategy On Syringa Pinnatifolia Var. Alanshanica

Syringa pinnatifolia var. alanshanica, an endemic species of Helan Mountain, is an endangered species of national protection categories 3. In this paper, the sexual and asexual reproductive strategy and genetic variation of Syringa pinnatifolia var. alanshanica were studied. The main contents and results were as follows:â‘ Capsule contains 1 to 4 seeds. In 1428 capsule, 55.04% capsule contain 1 seed , but only 3.57% contain 4 seeds. At the same time, statics show that there is a downward trend in capsule size and seeds quantity, while the size of seeds remain unchanged.â‘¡Seed consists of embryo, rich endosperm and thick coat. The germination rate of the seed was low, only 14%.â‘¢A suitable ISSR-PCR system for Syringa pinnatifolia var. alanshanica was established, it's 20μl reaction system contained 1 mmol/L 10×PCR buffer, 1.5 mmol/L Mg²⁺, 0.25 mmol/L dNTP, 1.0 U Taq DNA polymerise, 0.3μmol/L Primer, and 10-30ng DNA template. The amplification procedure conditions were predenature at 94FFC 5min, 45 cycles with denaturation 94FFC 1min, anneating at 52-54FFC 45s, extension at 72FFC 2min, and last estension at 72FFC 7min.â‘£Clonal diversity was high. At the species level, the average size of clones was 1.729, and simpson index was 0.994; at population level, the average size of clones was 1.709, and simpson index was 0.954.⑤The population was made of muti-cloning, and the proportion of clonal growth to sexul reproduction was approximately the same. The ramets of putative clone were from 2 to 8 and most of these clone only had 2 ramets. Cloning growth only existed in the same shrub and it taked a small space.â‘¥High genetic variation. At the species level (P=90.4%, H=0.297, I=0.452) and at population level (P=58.05%, H=0.206, I=0.303). The genetic variation was found to be partitioned mainly in populations, lower gene flow among natural population.