提高银杏叶黄酮含量的措施及其调控机理的研究(英文)

在银杏果用园,喷施矮壮素、脱落素及乙烯利均能提高叶黄酮含量,矮壮素效果最好,比对照提高了20.06%,与对照和其它处理间差异达到极显著水平,脱落酸与对照之间差异达显著水平。矮壮素处理效果最优的原因是它能促进光合积累,显著降低叶片中GA含量和IAA/ABA、IAA/ETH、GA/ABA、GA/ETH值。     

1895——1945年厦门茶业研究

厦门的茶业具有较久的历史传统,是一个传统强势产业,也是出口产品之中的大宗;在1895—1945年期间,厦门的茶叶生产因仍沿用传统的加工等方法,茶叶的产量一直难以突破,但仍是厦门港出口的主要品种之一,也是当地的一个比较重要的行业;在茶业发展的过程中,一直受到各种苛捐杂税的影响,这种现象较之其他地方要严重得多,是厦门港口茶叶出口日渐式微的原因之一;因茶业贸易的外向性色彩极浓,所以国内外时局的因素与国外政策的变化都会影响到厦门茶业的发展。     

Comparisons of vesicular-arbuscular mycorrhizal species and inocula formulations in a commercial nursery and on diverse Florida beaches

For efficient use of mycorrhizal inoculum the effectiveness of the isolate used and the rate of application required for maximum colonization must be known. The objectives of this research were to (1) define the lower limit of inoculum density required for maximum colonization of Uniola paniculata in a commercial nursery and (2) evaluate the performance of a selected native dune vesicular-arbuscular mycorrhizal (VAM) isolate versus a commercially available non-dune VAM (foreign) isolate on three diverse Florida beaches. An inoculum-dilution study was conducted in a commercial nursery with cutroot inoculum of a Glomus sp. that had been isolated from a Florida dune. Maximum colonization was achieved with approximately 1 propagule ml^-1 of growth medium. In a separate nursery study, 10 inoculation treatments (combinations of inoculum source and level) were established in the commercial nursery. Treatments included cut-root and sheared-root inoculum of the native dune isolate, and Nutri-Link, a commercial inoculum of G. intraradices. Colonized plants from selected treatments were transplanted to beach sites around Florida. At Miami Beach, after one growing season, the shoot mass of plants inoculated with the native isolate was approximately twice that of plants inoculated with the foreign isolate. At Katherine Abbey Hanna Park and Eglin Air Force Base there were no significant inoculum source effects on shoot mass or root length after one growing season. However, the native isolate produced a greater colonized root length than the foreign isolate in all plantings. The soil hyphal density was measured at Eglin Air Force Base, and the results showed that plants inoculated with the native isolate had more soil hyphae (4.33 mg^-1) than plants inoculated with the foreign isolate (3.65 mg^-1) or the non-inoculated plants (2.12 mg^-1). Even where there were no obvious shoot growth responses, mycorrhizal inoculation may have an important effect on dune stabilization, as soil hyphae are known to bind sand grains and improve dune stability.Publishedas Florida Agriculture Experiment Station Journal SeriesPublishedas Florida Agriculture Experiment Station Journal Series     

基于EPO算法去除水分影响的土壤有机质高光谱估算

野外进行土壤有机质的光谱快速预测时需考虑土壤含水量的影响。在室内设计人工加湿实验分别获取9个土壤含水量梯度(0~32%,间隔4%)的土壤光谱数据,分析土壤含水量变化对光谱的影响,再利用外部参数正交化法(external parameter orthogonalization,EPO)进行湿土光谱校正,并结合偏最小二乘回归和支持向量机回归分别建立土壤有机质预测模型。结果表明,土壤光谱反射率随着土壤含水量的增加呈非线性降低趋势,偏最小二乘回归模型的预测偏差比为1.16,模型不可用;经EPO算法校正后,各土壤含水量梯度之间的光谱差异性降低,能实现土壤有机质在不同土壤含水量梯度的有效估算,偏最小二乘回归和支持向量机回归模型的预测偏差比分别提高至1.76和2.15。研究结果可为田间快速预测土壤有机质提供必要参考。     

Sugar beet waste and its component ferulic acid inhibits external mycelium of arbuscular mycorrhizal fungus

External arbuscular mycorrhiza (AM) mycelium plays an important role in soil while interacting with a range of biotic and abiotic factors. One example is the soil organic amendment sugar beet waste. The fermented Aspergillus niger-sugar beet waste (ASB) increases growth and P uptake by the AM mycelium in soil whereas non-fermented waste (SB) had a strong inhibitory effect. The underlying mechanisms are not understood.We used gas chromatography-mass spectrometry to identify differences in composition of water extracts of ASB and SB. The chromatograms showed that ferulic acid was present in SB and absent in ASB. We compared the effects of the water extracts of SB and ASB and ferulic acid upon the growth of Glomus intraradices in in vitro monoxenic cultures.Hyphal growth of the AM fungus G. intraradices was extremely reduced in ferulic acid and SB treatments. Moreover, AM hyphae appeared disorganized, undulated and tangled. In contrast, ASB increased hyphal length and numbers of branched absorbing structures and of spores. We conclude that ferulic acid is one compound in SB which is responsible for its inhibition of AM extraradical growth. The relevance of these findings is discussed.     

添加乳酸菌和纤维素酶对茭白叶青贮品质的影响

为研究添加乳酸菌和纤维素酶对茭白(Zizania caclucifora)叶青贮品质的影响,试验设对照组(CK)、乳酸菌组(LAB, 乳酸菌1×10⁵ CFU·g^-1鲜草)、纤维素酶组(CEL, 纤维素酶1 g·kg^-1鲜草)和混合组(MIX, 乳酸菌1×10⁵ CFU·g^-1鲜草+纤维素酶1 g·kg^-1鲜草).桶装青贮,30 d后检测发酵品质.结果表明:添加乳酸菌和纤维素酶,可显著提高粗蛋白(CP),降低中性洗涤纤维(NDF)、酸性洗涤纤维含量(ADF);试验组pH、氨氮/总氮(NH₃-N/TN)值显著降低,乳酸含量、乳酸/乙酸值显著提高;试验组产气量、有机物消化率、氨氮和有机酸含量相比对照组显著提高.推荐使用乳酸菌(1×10⁵ CFU·g^-1鲜草)和纤维素酶(1 g·kg^-1鲜草)混合青贮茭白叶.     

基于制度经济学的基层灌溉管理单位改革探讨

基于制度经济学的分析框架,从促进灌溉农业可持续健康发展的角度来探索新时期最适合我国基层灌溉管理单位改革的制度安排。结果表明,既要坚持基层灌溉管理单位的公有属性,又要充分发挥集体的优越性,使两者成为一个利益共同体,才能解决行政命令下的低效率和完全市场化所带来理想与现实相脱离的困境。