荒漠植物骆驼蓬的繁殖生物学特性研究

Study on the reproductive biology characteristics of the desert plant Peganum harmala

为了探究荒漠植物骆驼蓬(Peganum harmala)的繁殖生物学特性,采用野外定点观察的方法研究其花部特征和开花动态、主要传粉昆虫和访花特性,并利用异交指数(OCI)、花粉胚珠比(P/O)来初步测定骆驼蓬的繁育系统。结果显示:(1)群体花期5月中旬至7月下旬,约80 d,单花花期2-3 d;雄蕊15枚,花药渐次开裂;子房3室,胚珠55-70枚,柱头呈三面微凹的三棱柱形;子房基部具有5个蜜腺窝,盛花期花蜜量较丰富;(2)OCI≥4,花粉-(P/O)为15443.9±1407.051,综合分析,初步推断骆驼蓬属于异交,部分自交亲和的繁育系统类型;(3)研究发现骆驼蓬具异型花柱,长花柱型花占多数,短花柱型花只占有极少的比例,存在雌雄异位现象,异位距离为0.067±0.0047 cm;(4)传粉昆虫主要为蜂类。日访花频率显示,在12:00左右达到最大值,16:00左右达到最低,到19:00之后又出现1个小高峰。此外,阴雨低温天气造成访花昆虫数量减少,与花冠闭合和延迟开花等现象相适应,这是植物长期对气候和访花昆虫相互适应的结果。

The reproductive biology characteristics of by fixed-point observation in the wild were studied inthe present study. The floral traits, flowering dynamics, major pollinators and their visiting characteristics inwere observed, and the out-crossing index（OCI ） and pollen/ovule ratio（ P/O） were used to determinate its breeding system. Theresults were as the follows （1） The flower season of the population lasted about 80 days from mid-May to late-July, and about2-3 days of a single flower; the 15 stamens dehisced gradually; 55-70 ovules were in the 3 rooms of the ovary, and thestigma was a concave triangular prism; five nectary nest were in the ovary base, and rich nectar appeared in the full-blossomstage.（2） The OCI≥4, and P/O=15443.9±1407.051, suggesting indicated that the breeding system was out-crossing, and partself-compatibility. （3） Distyly was found in , and the proportion of long-style flower was much more thanshort-style flower. Herkogamy was also found in , and the distance was 0.067 ± 0.0047 cm. （4） Bees werethe main pollinators. The frequency of daily visits reached the maximum at about 12 o＇clock and reached the lowest at 16o＇clock. After 19 o＇clock it was a little higher. In addition, the number of flower visiting insects decreased due to rainy andcold weather, which was consistent with the phenomena of corolla closure and delayed flowering. This was the result oflong-term adaptation to climate and flower visiting inserts.