科尔沁沙地124种天然植物粘液繁殖体的甄别

用粘沙法对科尔沁沙地西部124种天然植物进行了粘液繁殖体甄别。结果表明:(1)在124种植物中,有13种植物包括冷蒿(Artemisiafrigida)、万年蒿(A.gmelinii)、差不嘎蒿(A.halodendron)、野艾蒿(A.lavan-dulaefolia)、大籽蒿(A.sieversiana)、黄蒿(A.scoparia)、乌丹蒿(A.wudanica)、画眉(Eragrostispilosa)、小画眉(E.poaeoides)、百里香(Thymusmongolicus)、平车前(Plantagodepressa)、盐生车前(Plantagomaritima)、野亚麻(Linumstelleroides)的种子分泌粘液,占所有被测植物的10.5%;(2)综合浇水2mm和水浸20min两种处理结果发现,盐生车前、平车前、乌丹蒿、冷蒿、百里香粘液(粘沙)繁殖体比例很高,万年蒿、黄蒿、野艾蒿粘液繁殖体比例相对低;(3)综合浇水2mm和水浸20min处理结果发现,分泌粘液粘沙后重量变化较大的植物包括画眉、小画眉、盐生车前、乌丹蒿、万年蒿;(4)将水浸20min与浇水20mm处理的结果进行平均,得到的粘沙种子总粘沙量由小到大的顺序是:黄蒿 < 野艾蒿 < 万年蒿 < 小画眉 < 画眉 < 冷蒿 < 差不嘎蒿 < 大籽蒿 < 百里香 < 野亚麻 < 平车前 < 乌丹蒿 < 盐生车前;(5)全部13种有粘液繁殖体植物的种子均小,单粒重小于1mg;(6)无论对水浸20min,还是浇水20mm处理,粘沙种子粘沙量与未粘沙种子重量正相关,即种子越大,粘沙量越大;(7)蒿属植物占具有粘液繁殖体植物的比例较大,供试的7种植物均有种子分泌粘液,但在粘沙种子重量增加量、粘沙种子对未粘沙种子的重量倍数、粘沙种子百分数等方面表现物种间差异;(8)蒿属植物分泌粘液是其适应流沙的属性之一。

Screening on Myxospermy of 124 Species Occurring on the Sandy Habitats of Western Horqin Steppe

Myxospermy, a mechanism, where mucilage is produced upon being moistened, has been found in many species. Previous work indicates that myxospermy is frequently associated with species occurring in arid zones. There has been, however, little study on myxospermy with reference to a local flora. A screening on myxospermic diaspores of 124 species colonizing sandy habitats of western Horqin steppe, Inner Mongolia, was conducted to: (1) examine what species excrete mucilage, and (2) analyze the ecological significance of myxospermy. Myxospermy was judged by whether diaspores had the capacity to hold sand particles.Of the 124 species examined, 13 species, Artemisia frigida, A. gmelinii, A. halodendron, A. lavandulaefolia, A. sieversiana, A. scoparia, A. wudanica (Asteraceae), Eragrostis pilosa, E. poaeoides (Gramineae), Thymus mongolicus (Lamiaceae), Plantago depressa, P. maritime (Plantaginaceae) and Linum stelleroides (Linaceae) had myxospermic diaspores, accounting for 10.5% of the total species examined. In both treatments, i.e. soaking for 20 min and watering with 2 mm rainfall, Plantago depressa, P. maritime, Artemisia frigida, A. wudanica and Thymus mongolicus had a high proportion of myxospermic diaspores, but Artemisia gmelinii, A. scoparia and A. lavandulaefolia had a low one. In both treatments, big changes of diaspores in weight after sand-holding happened in the species such as Eragrostis pilosa, E. poaeoides, Plantago maritime, Artemisia wudanica and A. gmelinii. The mean amount of sand held by mucilaginous diaspores in both treatments was ordered as: Artemisia scoparia< A. lavandulaefolia, A. gmelinii