【作者】 刘智微；

【导师】 钟小仙； 沈益新；

【作者基本信息】 南京农业大学 ， 草业科学， 2011， 硕士

【摘要】 象草(Pennisetum purpureum Schumach),原产热带非洲,抗逆性强、适应性广光合效率高,可作为草食畜禽和鱼类的优质青饲料、水土保持植物、优质纸浆和人造板原料,还是重要的生物质能源作物。苏牧2号为2010年国家审定的耐盐象草新品种,是以N51为原始材料,利用细胞工程手段筛选出来的体细胞突变型耐盐象草。本试验以N51象草为对照,研究了0、4、6、和10g/L海盐浓度条件下苏牧2号象草幼苗生长情况、形态特征、植株不同部位阳离子积累及叶片抗氧化酶的变化规律,以期为盐渍土的高效生态利用和象草产业化开发提供技术支撑。试验结果如下：(1)随海盐浓度的升高,苏牧2号和N51的株高、植株各部分干重均呈降低的趋势,叶片损伤情况加重；随胁迫时间的延长,海盐对两品种生长的抑制作用均逐渐显著。4g/L、6g/L和10g/L海盐浓度处理下,N51的相对枯叶率和枯叶干重率在胁迫后第28d分别是苏牧2号的1.27、1.25、1.09和1.44、1.20、1.15倍,苏牧2号茎和鲜叶的干重均显著高于N51。(2)随海盐浓度的升高,苏牧2号和N51植株各部分Na+含量升高,K+、Ca2+、Mg2+含量和K+/Na+降低。相同海盐浓度胁迫下,苏牧2号和N51植株各部分Na+含量为叶<茎<根,K+含量为根<叶<茎,K+/Na+为根<茎<叶,Ca2+含量为根<茎<叶,Mg2+含量为叶<根<茎。其中,4～10g/L不同海盐浓度胁迫下,苏牧2号和N51根中的K+/Na+均无显著差异；苏牧2号茎中的K+/Na+均高于N51,各浓度下显著性差异不尽相同；除海盐浓度4g/L、处理28d苏牧2号叶中的K+/Na+与N51无显著差异外,叶中的K+/Na+苏牧2号均显著高于N51；苏牧2号的SK+/Na+(stem/root)除海盐浓度4g/L、处理7d低于N51外,苏牧2号均高于N51,是其运输系数的1.02-2.19倍。(3)0～6g/L浓度海盐胁迫下,苏牧2号和N51的SOD和POD活性在胁迫后第14d、21d和28d,MDA含量在胁迫后第7d、14d和28d随海盐浓度的升高而升高,CAT活性随海盐浓度的变化与海盐胁迫时间存在交互作用。相同浓度海盐胁迫下,苏牧2号的SOD和POD活性均极显著高于N51；除海盐浓度为4g/L和6g/L时,胁迫后第7d苏牧2号与N51的CAT含量无显著差异外,苏牧2号的CAT活性均显著高于N51。除海盐浓度为0g/L时,胁迫后第28d苏牧2号与N51的MDA含量无显著差异外,苏牧2号MDA含量均极显著低于N51。而10g/L海盐胁迫下,苏牧2号和N51生长至21d时已全部死亡。(4)随海盐浓度升高,苏牧2号和N51表皮气孔总密度、表皮毛总密度及泡状细胞长度增大,叶片横切面面积/维管束数目苏牧2号逐渐减小,而N51为0g/L>6g/L>4g/L>10g/L,6g/L比4g/L高6.98%。相同海盐浓度胁迫下,0g/L处理下,表皮气孔总密度苏牧2号与N51无显著差异,4～0g/L处理下苏牧2号显著高于N51。叶片横切面面积/维管束数目除4g/L处理下苏牧2号比N51高13.69%外,均低于N51；细胞深陷程度在0g/L和4g/L下低于N51,在6g/L和10g/L下高于N51；表皮毛总密度为0～6g/L低于N51,10显著高于N51。更多还原

【Abstract】 Purpureum Pennisetum Schumach was native to tropical African, it has a strong resistance, wide adaptability, highly photosynthetic efficiency, and can be used for the high quality green fodder for fish and herbivores, plant of water and soil conservation, raw materials of high quality pulp and man-made board, and it is important energy crops. Sumu No.2 is a new saline-variety of Purpureum Pennisetum Schumach which was authorized in 2010 by national. It used N51 for raw materials to get Purpureum Pennisetum Schumach of salt resistance by cell engineering screening out of somatic mutations. Seedling growth situation, morphological characteristics, cationic accumulation of different parts of plant and variation rules of antioxidative activity and MDA content of leaves were studied. It could provide technical support for the efficient and ecological using of saline soil and the industrial application of Sumu No.2 on the saline soils.The results are as follows:(1) The plant length, dry weight of different parts of plant of Sumu No.2 and N51 decreased and damage degree of leaf increased with the sea-salt concentration increased; Growth inhibitory gradually significant under different sea-salt concentration after prolonged sea-salt stress time. Under 4g/L,6g/L and 1 Og/L sea-salt concentration, the relative deied leaf rate and deied leaf DW rate of N51 were 1.27,1.25,1.09 and 1.44,1.20,1.15 times of Sumu No.2 after 28d treatment. The dry weight of SuMu 2 stem and fresh leavse was significantly higher than N51.(2) With sea-salt concentration increasing, Na+content increased and K+、Ca2+、Mg2+ content and K+/Na+ reduced in different parts of Sumu No.2 and N51 plants. Na+ content in different parts of Sumu No.2 and N51 plants was:leaf<stem<root,K+ content was: root<leaf<stem,K+/Na+ was:root<stem<leaf,Ca2+ content was:root<stem<leaf and Mg2+ content was:leaf<root<stem under the same sea-salt concentration stressed.Under 4～10g/L sea-salt concentration stressed, K+/Na+ of Sumu No.2 has not significant difference in roots with N51, higher than N51 in stems, significantly higher than N51 in leaves besides that Sumu No.2 and N51 have not significantly different under 4g/L treatment after 28d stressed; S K+/Na+ (stem/root) ability of Sumu No.2 were 1.02-2.19 times of N51 in addition to Sumu No.2 lower than N51 under 4g/L treatment after 7d stressed.(3) The results showed that SOD and POD activities of Sumu No.2 and N51 increased with the increasing of sea-salt concentration after 14d,21d and 28d of stressed, the content of MDA increased with sea-salt concentration increasing after 7d,14d and 28d of stressed and CAT activity had interactive effects between the stress of sea-salt concentration and time under the stress of 0～6g/L sea-salt concentration. The activity of SOD and POD of Sumu No.2 very significantly (P<0.01) higher than those of N51, CAT activity was significantly (P<0.01) higher than that of N51 except that 4g/L and 6g/L of sea-salt concentration after 7d stressed, MDA content was obviously (P<0.05) lower than those of N51 besides Og/L of sea-salt concentration after 28d stressed. Sumu No.2 and N51 were all dead under lOg/L sea-salt stressed in 21d.(4) Total density of stomatal and leaf hair and bulliform cell length of Sumu No.2 and N51 increased with the increasing of sea-salt concentration. Leaf total cross-sections per Vascular bundle number of Sumu No.2 decresed, N51was:0 g/L>6 g/L> 4 g/L> 10 g/L(6 g/L higher than 4 g/L for 6.98%) with the increasing of sea-salt concentration. Leaf total cross-sections per Vascular bundle number of Sumu No.2 lower than N51 except that higher than N51 for 13.69% under 4g/L of sea-salt concentration stressed; Bubbly cells length of Sumu No.2 lower than N51 under Og/L and 4g/L of sea-salt concentration stressed and higher than N51 under 6g/L and 10g/L of sea-salt concentration stressed; Stomatal total density of Sumu No.2 extremely higher than N51 except that lower than N51 under 0g/L of sea-salt concentration stressed.更多还原