盐分对碱茅种子发芽影响的机制

耐碱茅种子在盐（NaCl与Na2SO4）及干旱（PEG－6000模拟）胁迫下发芽及其机制的比较研究表明，种子发芽率随溶液渗透势的降低而下降，在等渗条件下三种溶液中的发芽率次序为Na2SO4＞NaCl＞PEG。NaCl与Na2SO4主要通过影响种子吸水量及对膜的毒性影响发芽，根据相关及通径分析结果，其机制为：（1）溶液渗透势及Na+浓度决定的种子吸水对发芽的直接正效应（通径系数0．73）；（2）溶液Na+浓度引起的膜毒性对发芽的直接负效应（－0．51）；（3）种子从溶液中吸收Na使种子吸水增加对发芽的间接正效应（0．30）及使膜毒性增大对发芽的间接负效应（－0．24）。     

Restoration of tuber production by exposure to unshaded daylight in Eleocharis kuroguwai Ohwi shaded during the early tuber formation period

The loss of final tuber weight of Eleocharis kuroguwai Ohwi by shading during the early tuber formation period (TFP) is overcome by exposure to unshaded daylight thereafter (late TFP). In the present study, the growth parameters that contribute to the dry matter increase (DMI) per day of tubers in the late TFP were examined. DMI of the tuber during the late TFP was determined by that of the whole plant and the ratio of the DMI of the tuber to that of the whole plant during this period. The ratio of the DMI of the tuber to that of the whole plant during the late TFP was significantly correlated with the DMI of the whole plant during the first 14 days of the late TFP. During the late TFP after the exposure to unshaded daylight, DMI of the whole plant correlated with the surface area of the stem (SAS) and net assimilation ratio (NAR), and the SAS correlated with the stem dry weight (DW) and specific stem-surface area (SSA). SSA negatively influenced NAR, but NAR was increased by unshading. During the late TFP after shading, the effect of the decrease of the stem DW due to shading on the DMI of the whole plant was mitigated by the large SAS and high NAR. These results indicate that the growth parameters that contribute to the DMI of tuber during the late TFP after exposure to unshaded daylight are SAS and NAR just after unshading, and SSA during this period.     

几种牧草对河西走廊盐渍化土壤改土培肥的效应研究

在河西走廊盐渍化土地上种植老芒麦、扁穗冰草、碱茅和紫花苜蓿4种优质牧草,对盐渍化程度均有一定的改良效果.其中碱茅对盐渍化土壤的改土培肥效果最好,建植3年后的碱茅,与对照比较,0～20 cm土层中自然含水量增加125.99 g/kg,总孔度增加16.14%,容重降低0.27 g/cm3,pH值由8.43降到8.10,全盐含量降低52.90 g/kg,脱盐率达到76.12%,有机质增加3.67 g/kg,碱解氮含量增加18.63 mg/kg,速效磷和钾亦随之增加.     

漆姑草属抗癌植物药学及生态价值研究概况

漆姑草是传统治疗漆疮的良药,其药用及生态价值有待进一步开发。在广泛文献检索的基础上,对漆姑草的鉴定、成分、药理、临床应用、生态价值及栽培技术等进行了概述,为深入研究和开发利用提供科学资料。     

“吉农朝鲜碱茅”与“三北”地区盐碱地的改良

简述了国内外盐碱地的现状与分布，生物改良盐碱地的方法，已被科学家们所共识。我们利用碱茅属（Puccinelia Parl）植物改良盐碱地已取得重大进展。新育成的“吉农朝鲜碱茅”（P．chinampoesis Ohwi CV．“Jinong”）具有更加优良的性状和广泛的适应性。该品种将在“三北”地区的生态环境建设和盐碱地改良过程中发挥重要作用。     

NaCl对碱茅游离氨基酸成分及脯氨酸等含量的影响

分析了NaCl胁迫下碱茅幼苗中15种游离氨基酸的消长规律。结果表明在适境条件下碱茅地上部脯氨酸占总游离氨基酸的10.53％,盐逆境下脯氨酸稳定地增加。随着盐浓度的升高,碱茅地上部中丝氨酸增加倍数较大,精氨酸含量降低或略有增加;其地下部中丝氨酸含量增加甚小,精氨酸含量在一定盐度范围内增加较大。此外NaCl胁迫下,处理1,2及3植株地上部中蛋白质含量分别下降了3.46％,7.55％和7.04％,淀粉含量分别下降了3.53％,11.81％和12.35％;其地下部中蛋白质含量分别增加了4.15％,2.04％和2.18％。处理1和2淀粉含量增加了1.45％和2.93％,处理3淀粉含量下降了2.92％。     

小豆生长发育规律的研究——Ⅲ.小豆籽粒灌浆进程及播后籽粒干物质转移速率的研究

研究表明:小豆开花后籽粒干物质积累以及播后籽粒干物质转移后的残留量变化呈正态曲线。播后第8天前后为幼苗自身供养与异养的临界期,生育后期的中期为籽粒灌浆的快速时期。     

不同施氮肥时期对朝鲜碱茅种子和干草产量的影响

朝鲜碱茅在分蘖期、拔节期和孕穗期施氮肥试验结果表明,各不同施肥时期种子和干草产量之间有极显著差异,拔节期施氮肥增产效果最好。种植第四年的朝鲜碱茅,施N138.00kg/hm2,种子和干草产量分别为482.00kg/hm2和6606.67kg/hm2,分别比对照增产193.31%和227.12%,施肥并可增加经济效益。     

NaCl和Na2CO3对星星草生长及营养液中主要矿质元素存在状态的影响

星星草生长在０－６００ｍｍｏｌ／ＬＮａＣｌ和０－２００ｍｍｏｌ／ＬＮａ２ＣＯ３的盐胁迫下，测定了其生长状况及营养液中主要矿质离子的游离度、活度等。结果表明：相同Ｎａ＾＋活度下，Ｎａ２ＣＯ３对星星草的生长尤其是根生长的抑制作用明显大于ＮａＣｌ。