对南京试验地种植的香根草[Vetiveria zizanioides (L.) Nash]叶片的光合特性和主要矿质元素含量以及株高生长速率进行了测定,并对来源于南京试验地和东台滩涂地的香根草叶片中与纤维特性有关的化学组分的含量及水解产物的含量进行了分析和比较。结果显示:香根草叶片的净光合速率(Pn) 对光量子通量密度的响应曲线呈单峰型,Pn 最高可达15. 3 μmol·m^-2 ·s^-1 ,光饱和点为1 528. 6 μmol·m^-2 ·s^-1 ;Pn 日变化曲线呈明显的双峰型,峰值分别出现在10:00 和15:00。叶片中K、N、Ca、P、Mg 和S 的含量分别为11. 2、7. 6、4. 3、2. 7、2. 8 和1. 5mg·g^-1 。5 月份至10 月份是香根草的快速生长期,7 月份的株高生长速率最高,达42. 1 cm。种植于试验地和滩涂地的香根草叶片中纤维素、半纤维素和木质素的含量分别为326. 1 和321. 7 mg·g^-1 、380. 2 和369. 5 mg·g^-1 、147. 8 和154. 0 mg·g^-1 ,产地间差异不显著(P>0. 05);苯-乙醇抽提物和灰分的含量分别为59. 5 和54. 1 mg·g^-1 、81. 7 和71. 7 mg·g^-1 ,产地间差异显著(P<0. 05)。种植于试验地和滩涂地的香根草叶片水解产物中葡萄糖和木糖含量均较高,分别为368. 3 和359. 9 mg·g^-1 、245. 7 和204. 3 mg·g^-1 ;阿拉伯糖、半乳糖和甘露糖含量较低,三者的总含量仅为58. 6 和55. 8 mg·g^-1 ;其中,仅木糖含量产地间具有显著差异(P<0. 05)。研究结果表明:香根草具有很强的光合能力及较快的生长速率,叶片中纤维素和半纤维素含量均较高,能够适应边际性土地种植,是一种潜在的优良木质纤维素能源植物。

The photosynthetic characteristics and main mineral elements content in leaf and height growth rate of Vetiveria zizanioides (L.) Nash cultivated in experimental field in Nanjing were determined, and contents of chemical components related to fiber property and of hydrolysis products in leaf of V. zizanioides cultivated in experimental field in Nanjing and beach in Dongtai were analyzed and compared. The results show that response curve of net photosynthetic rate (Pn) with photon flux density of leaf is a single peak curve with a max Pn of 15. 3 μmol·m^-2 s^-1 and light saturation point of 1 528. 6 μmol·m^-2 ·s^-1. And daily change curve of Pn is an obvious double peak curve with the two peaks appearing respectively at 10:00 and 15:00. The contents of K, N, Ca, P, Mg and S in leaf are 11. 2,7. 6, 4. 3, 2. 7, 2. 8 and 1. 5 mg·g^-1, respectively. The rapid growth period of the species is from May to October and height growth rate in July is the highest with 42. 1 cm per month. Contents of cellulose, hemicellulose and lignin in leaf of V. zizanioides cultivated in experimental field and beach are 326. 1 and 321. 7 mg ·g^-1, 380. 2 and 369. 5 mg ·g^-1, 147. 8 and 154. 0 mg · g^-1, respectively, without significant difference between different locations ( P > 0. 05 ). While contents of benzene-ethanol extractives and ash are 59. 5 and 54. 1 mg·g^-1, 81. 7 and 71. 7 mg·g^-1, respectively, with significant difference between different locations (P <0. 05). Among hydrolysis products in leaf of V. zizanioides cultivated in experimental field and beach, contents of glucose and xylose all are higher with 368. 3 and 359. 9 mg·g^-1, 245. 7 and 204. 3 mg·g^-1, respectively, and contents of arabinose, galactose and mannose are lower with total contents of 58. 6 and 55. 8 mg·g^-1, respectively. In which, only xylose content has the significant difference between different locations (P <0. 05). It is concluded that V. zizanioides has a very high photosynthetic capacity, fast growth rate, relative high contents of cellulose and hemicellulose in leaf. And it can grow well in the marginal land and be considered as a potential lignocellulosic energy plant.