【摘要】：草原毒害草的肆意蔓延,使草原生態(tài)急速惡化,不但嚴重影響了當地農牧民的收入和畜牧業(yè)的發(fā)展,而且也導致草地的進一步退化,所以對草原毒害草地的防控勢在必行,而明確自然狀態(tài)下毒害草種群擴繁更新機制對于其防控十分重要。研究以天山北坡分布最為廣泛的草原毒草-醉馬草為研究對象,一方面采用常規(guī)培養(yǎng)皿紙上發(fā)芽法,通過設置不同萌發(fā)條件,如溫度、光照、水分等,探討不同生境條件下醉馬草種子萌發(fā)特征的異同及其響應規(guī)律;另一方面采用野外常規(guī)取樣,通過對醉馬草種群株高、株叢徑、分蘗數、構件生物量及其分配等指標的測定,探討不同生境條件下醉馬草外觀表型特征的差異及其變化,繼而為醉馬草種群擴繁機制的揭示、綜合防控和資源開發(fā)提供有力依據。主要研究結果如下:(1)不同生境下新疆醉馬草種子的發(fā)芽率、發(fā)芽指數、發(fā)芽勢、胚芽長和胚根存在一定的差異性。與全光照相比,恒溫條件下黑暗處理明顯提高了醉馬草的發(fā)芽勢、發(fā)芽率、胚芽長及發(fā)芽指數(P0.05),且25℃時萌發(fā)最佳,發(fā)芽勢、發(fā)芽率、發(fā)芽指數平均依次為73.6%、92.3%、8.2。無論光照與否,10/20℃下4份醉馬草種子的發(fā)芽率、胚根長、胚芽長、發(fā)芽指數都明顯高于5/20℃(P0.05)。隨海拔升高,醉馬草種子發(fā)芽勢、發(fā)芽率、發(fā)芽指數呈降低趨勢,而胚芽長及胚根長則相關不顯著(P0.05)。(2)低濃度PEG(5%~10%)可促進醉馬草種子的發(fā)芽,高濃度PEG(15%)則會抑制醉馬草種子發(fā)芽勢、活力指數、發(fā)芽指數、胚芽長,促進胚根的生長;PEG脅迫下不同來源的醉馬草種子發(fā)芽率、發(fā)芽指數、發(fā)芽勢間差異顯著(P0.05),且高海拔地區(qū)(2287 m)的醉馬草抗旱性低于中低海拔地區(qū)(1650~1832 m)。(3)隨海拔增加,醉馬草單株生殖枝數、花或果實重、株高呈降低趨勢;不同生境間醉馬草的地下生物量、根系長度差異不顯著(P0.05),依次為37.5 g/株~92.1 g/株、6.6 cm~7.9 cm;地上生物量6月材料A4顯著高于材料A6、A5,7月材料A5顯著高于材料A6、A4(P0.05),而其長軸長、短軸長及冠幅面積僅在7月顯著差異(P0.05),且材料A5顯著低于材料A4、A6(P0.05)。(4)從地上構件生物量看,6月,不同生境間醉馬草莖重差異不顯著(P0.05),葉重材料A4顯著高于材料A5、A6;7月,材料A5莖重顯著高于材料A6、A4(P0.05),而葉重則差異不顯著(P0.05);低海拔材料花或果實重顯著高于高海拔區(qū)域(P0.05)。生物量分配看,醉馬草將生物量向葉、莖、花或果實的分配比例呈降低趨勢,依次為48.2%~80.2%、13.5%~30.0%、0.7%~21.8%,且不同生境間表現并不一致;莖分配比例僅在7月表現為材料A5顯著高于材料A6、A4(P0.05);6月~7月材料A4、A6的葉分配比例顯著高于材料A5(P0.05),而材料A5、A6的花或果實分配比例高于材料A4。
[Abstract]:The wanton spread of the poisonous grass in the grasslands has caused the rapid deterioration of the grassland ecology, which not only seriously affected the income of the local farmers and herdsmen and the development of animal husbandry, but also led to the further degradation of the grassland, so it is imperative to prevent and control the grassland poisoning the grassland. It is very important to define the mechanism of populating and renewing poisonous grass population under natural condition. In this study, the most widely distributed steppe poison grass on the north slope of Tianshan Mountain, the Daphnia sinensis, was studied. On the one hand, by setting different germinating conditions, such as temperature, light, moisture and so on, the method of germinating on common petri dish paper was used. The differences and similarities of seed germination characteristics and their responses in different habitats were discussed. On the other hand, the plant height, cluster diameter, tiller number, component biomass and their allocation were measured by conventional sampling in the field. To explore the differences and changes of phenotypic characteristics of Elaeagnus chinensis under different habitat conditions, and then to provide a powerful basis for revealing the mechanism of population propagation, comprehensive prevention and control and resource development. The main results were as follows: (1) there were some differences in germination rate, germination index, germinating potential, germ length and radicle under different habitats. Compared with the total light, the germination potential, germination rate, germ length and germination index (P0.05) were significantly increased under the condition of constant temperature, and the best germination at 25 鈩，

本文編號：2127472