海南飘拂草属叶下表皮微型态研究

利用光学显微镜技术观察飘拂草属16个种、2个亚种的叶下表皮微型态。结果显示:飘拂草属植物叶下表皮主要由长细胞和气孔器细胞组成,其中长细胞呈现长筒形、短筒形,少数为多边形;气孔器通常1~3列分布于脉间;保卫细胞哑铃型,两端明显或不明显加厚;副卫细胞圆屋顶形、圆屋顶形至三角形、低圆屋顶形或三角形。这表明不同种间叶下表皮特征表现出一定的差异,对种的划分具有一定的分类鉴定意义。     

海南飘拂草属叶下表皮微型态研究

利用光学显微镜技术观察飘拂草属16个种、2个亚种的叶下表皮微型态。结果显示：飘拂草属植物叶下表皮主要由长细胞和气孔器细胞组成,其中长细胞呈现长筒形、短筒形,少数为多边形;气孔器通常1～3列分布于脉间;保卫细胞哑铃型,两端明显或不明显加厚;副卫细胞圆屋顶形、圆屋顶形至三角形、低圆屋顶形或三角形。这表明不同种间叶下表皮特征表现出一定的差异,对种的划分具有一定的分类鉴定意义。     

The effects of sowing depth and flooding on the emergence, survival, and growth of Fimbristylis miliacea (L.) Vahl

Glasshouse experiments were conducted from March to July 2003 to determine the effects of sowing depth, and the time, duration, and depth of flooding on the emergence, survival, and growth of Fimbristylis miliacea (L.) Vahl. The treatments that were evaluated in the first experiment were three seeding depths (0, 0.5, and 1.0 cm), while in the second experiment, three flooding depths (saturated soil with no standing water and soil with water depths of 5 and 10 cm) and three flooding durations (7, 14, and 21 days from sowing) were evaluated. In the third experiment, three flooding depths (saturated soil with no standing water, and soil with water depths of 5 and 10 cm) and four flooding regimes (7, 14, 21 or 28 days after sowing [DAS]) were evaluated. Surface seeding gave the highest emergence rate compared to the 0.5 cm and 1.0 cm soil depths. A significantly higher emergence rate was recorded with the saturated conditions than with the flooded conditions. A flooding duration of ≥ 14 days showed a clear trend of reduced emergence with increasing flooding depth. A significantly higher survival rate, plant height, root length, number of leaves, and dry matter were recorded at soil saturation followed by the 5 cm and 10 cm flooding depths when flooding was simulated at 7 and 14 DAS. When the flooding was delayed to 21 and 28 DAS, the 10 cm flooding depth was required to suppress this weed. The results provide sufficient evidence to confirm that from deeper seed burial (1 cm sowing depth), flooding depths of ≥ 5 cm of durations of 14 and 21 days and at the onset of flooding within 14 DAS were effective in suppressing the emergence and growth of F. miliacea .     

水稻和两种野生植物对酸性硫酸盐土耐性及矿质元素吸收

酸性硫酸盐土是发育于还原性硫化物成土母质的一种恶劣土壤类型,虽然其分布区气候条件十分有利于水稻生长,但由于土壤条件限制,水稻生产潜力难以发挥。为筛选出适应该土壤的水稻品种,在酸性硫酸盐土(pH 3.69)上种植了240个水稻品种,但是所有水稻品种均未获得经济产量,却发现两种野生植物在该土壤中生长茂盛。经形态和分子鉴定,两种野生植物为野荸荠(Eleocharis kuroguwai)和五棱飘拂草(Fimbristylis quinquangularis)。进一步分析了水稻和两种野生植物的根际和非根际土壤性质、根部和地上部矿质元素含量。结果表明,根际土壤pH、交换性铝和有效锰含量不能解释水稻和两种野生植物耐性差异,锰毒和缺氮亦不是酸性硫酸盐土限制植物生长的关键因子,而植物地上部矿质元素含量与植物耐性差异相关。铝毒、铁毒和较低的养分(磷、钾、钙、镁)吸收是酸性硫酸盐土中水稻生长不良的主要因子。相反,两种野生植物对铝毒和铁毒的耐性较强,对养分吸收能力较强,所以生长良好。     

海南飘拂草属植物资源调查及饲用价值评价

对海南岛分布的莎草科飘拂草属植物资源进行了调查、收集与整理,共收集到飘拂草属植物 27 种、1 亚种, 2 变型,其中收集《海南植物志》未记载的有 1 种。对调查和收集的 20 种飘拂草属牧草的营养价值进行了分析,并通 过隶属函数法对所有供试材料综合评价,结果表明：双穗飘拂草营养价值最优,其次是绢毛飘拂草和披针穗飘拂草, 这些牧草的营养价值综合评价较高。具有一定的开发利用价值,开展对海南飘拂草属植物资源调查及饲用价值评价为 开发利用飘拂草属植物资源提供理论参考。