【作者】 杨渺；

【导师】 毛凯； 杨春华；

【作者基本信息】 四川农业大学 ， 草业科学， 2002， 硕士

【摘要】 本试验设立了四个遮荫梯度(0％、25％、45％、75％的光照)来研究遮荫对四川两种野生假俭草居群(峨嵋、雅安)的影响，以及它们在遮荫逆境下形态学、叶绿素含量、生物量等方面的差异性，并通过分析这些差异来确定这两种假俭草耐荫性的相对强弱。研究结果表明： 1．在遮荫情况下，雅安居群与峨嵋居群叶片的长度、宽度，节间长度、草层高度皆随遮荫梯度的增加而增加，茎的直径随遮荫梯度的增加而下降。雅安居群随遮荫度变化的幅度比峨嵋居群大。除0％遮荫梯度外，其余的处理都没见有植株开花。 居群雅安的生殖枝高度较高，小穗较长、较窄，平均小穗粒数较多，但千粒重小于峨嵋。所有这些指标都可以说明，雅安居群比峨嵋居群更具有阴生植物的特点，更适合于遮荫条件下生长。 两者的生物量主要由地上部分组成，地上生物量与总生物量的比值都在0.88以上。遮荫度越大，两居群地上部分所占的比重也越大。雅安的生物量小于峨嵋，但地上/总生物量、叶量/茎量的值较大。 2．叶绿素a、b的含量与遮荫梯度正相关，而叶绿素a/b则与遮荫梯度负相关(P＜0.01)。峨嵋假俭草叶绿素a、b的含量高于雅安，而各处理下雅安假俭草叶绿素a/b的值及生长过程中的增率大于峨嵋。 随遮荫梯度的增加，两居群可溶性总糖量增加。从生长旺季到生长后期，雅安的平均可溶性糖的增加率为3.145，峨嵋假俭草的平均增加率为2.565，小于雅安假俭草(P＜0.1)。 两居群间脯氨酸含量差异显著(P＜0.05)，峨嵋假俭草居群的脯氨酸含量平均为81.965μg/g.dw，高于雅安假俭草居群的64.498μg/g.dw。不过，0％到45％的遮荫梯度下，雅安假俭草的脯氨酸含量迅速增加，峨嵋假俭草脯氨酸含量则下降。更多还原

【Abstract】 Four levels of shade degree(0% 25癒 45 % 75 % of full sunlight) were set to study the effects of shade stress on the two local population of centipede grass (Emei, Ya’an) of sichuan, and the difference of Emei and Ya’an in Morphology, contents of chlorophyll, biomass under shade stress. The result indicate:1. Living under shade condition, The length and width of leaf lamina , internodes, and canopy height is increase ,but Stolon diameter decrease along with the increment of shade level. Ya’an has greater increment than Emei in all this morphology parameter.No two populations flowers, except under 0% shade level. Yaan’s inflorescence culm is higher than Emei. Its spike inflorescence longer and narrower compares to Emei and has more seeds, but seeds weight per 1000 grain less than Emei. All these parameters show that Ya,an has more characters of shade acclimating plants, so is more shade tolerance than Emei.Biomass of the two population is mainly make up of upground parts, and the ratio of upground/total-biomass all over 0.88. the more shade degree, the greater portion of upground parts the two population owns. Although Ya’an has less biomass than Emei, its ratio of upground/total-biomass, leaf/stolon-biomass is greater than Emei.2.Chlorophyll content of population Emei and Ya’an has positive correlation (P<0.01), while chlorophyll a/b has negative correlation (PO.01) with shade degree. Population Emei owns higher content of chlorophyll a, b, while Ya’an owns higher ratio of a/b and increment during growth under all treatments.With the increment of shade degree, the total soluble carbohydrate is increases. From the prosperity to telophase season of growth, Ya’an owns higher increasing39ratio of mean contents of soluble carbohydrate of 3.145, than Emei of 2.565.Proline contents of population Emei and Ya’an is different significantly (P<0.05). The proline contents of Emei are 81.965 ug/g.dw, higher than Ya’an of 64.498 ug/g.dw. From 0% to 45% of shade degree, the contents of proline of Ya’an increases, while Emei population has a decreased proline contents.更多还原