The Reproductive Ecology Of Hypecoum Erectum L.(Poppy Family)

The environment of Gurrbantuggut desert is harsh and varied in early spring. Less species of flowering plants and pollinating insects. So, the plant which is growing in the early spring, maily by its special structure, breeding system, and the relationship between pollinators and breeding strategies to adapt the harsh environment. Study the reproductive biology characteristics of early spring flowering plants will have important scientific significance for reveal the relationship between pollinators and plants. H.erectum belongs to Hypecoum and poppy family. It is a kind of psammophytes ephemeral plant distribution in Xinjiang. Through analysis the investigation data we found that the H.erectum are distributed in the southern margin of the Gurrbantuggut desert with patches and the area of the population is shrinking continuously. The study of this paper is to through the flowering phenology, floral characteristics, pollination characteristic, breeding systerm and seed germination to explore the reproductive ecology characteristics of H.erectum, and understand the reproductive adaptation countermeasures under the extreme desert habitat. The mainly results were as folloes:1. To analyze the flowering phenology characteristics through observing the flowering phenology variation at the population, individual, inflorescence and single flower levels, and combining with flowering amplitude and synchrony index. The flower phase of H.erectum is late April to late May, the flowering span of the population, individual, infloresence and single flowering were approximately 37-40 d、14-16 d、13-15 d and 1-2 d, respectively. The flowering amplitude was a curve with single apex, the synchrony index was 0.748. H.erectum exhibited a so-called―mass-flowering‖pattern, which was the adaptive strategy to unpredictable disturbance in desert habitat.2. To examine the pollination strategies and the ecological evolution meaning under desert habitat through a series of comparison about floral characteristic and pollination characteristics. H.erectum has the special floral characteristics, the inner petals is constituted with white lateral lobe and yellow middle lobe. The middle lobe, which on the two inner petals is specialized as a yellow cucullate structure. The middle lobe will reflexively wrap the anther as soon as the anther dehiscence, obtaining pollen and growing upward. The cucullate structure is the key functional organ in attracting pollinators and secondary pollen presentation. All the anthers were dehiscence at phase II. H.erectum primarily relyed on nectar, single flower color and the stamens mimicry of middle lobe to attract pollinators in unstable pollination environment. Colletes vestitus is the only effecity pollinators of H.erectum, the visiting frequency showed double-climax: 12: 00-13: 00 and 19: 00-20: 00.3. To analyze the breeding system type and the mating system under the desert habitat through artificial pollination experiment to explore the adaptation and the evolution significance. The duration of pollen viability is 4 d. The duration of stigma receptivity about 48 h, the stigma always have receptivity along the flower phase. The breeding system type of H.erectum is mixed mating system. A part of floral shows self-compatible and another shows outcross. The pollen of geitonogamy is contribute to their reproductive success. Under the selection pressure for a long time, the H.erectum tend to mixed mating system, could be a response to adapt the adverse the environment conditions in desert.4. To analyze the influence factors of external to explore the seed germination characteristics of H.erectum. The shape of H.erectum is rectangle and length and width of 0.96±0.04 mm and 0.±0.03 mm, respectively. There are a protuberance with ―X‖ at the side. Under certain conditions, there are significant difference in different treatment, concentration of 400 mg/L gibberellin makes the seed germination rate is the highest, is 81.3±0.70%; There are also have significant difference in the four temperature, the optimal temperature of seed germination is 15/25℃, the germination rate is 69.33±3.34%; Under the three kinds of illumination conditions, there are also have significant difference among seed germination rate.From the reproductive ecology angle, we should reduce the man-made disturbing to alleviate the fragmentation situation, and consequently the reproductive success rate will be improved.