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21.
以栽植于日光温室中适宜延迟栽培的‘贝达’砧‘意大利’葡萄为试材,自2013年8月1日始至落叶(2014年1月31日)止每天分别进行红光和蓝光不同光质延长光照至24:00补光处理,以不补光作为对照,研究不同光质补光处理对葡萄叶片衰老过程中叶片的外观形态特征、叶绿素含量、净光合速率、F_v/F_m、可溶性蛋白质含量和叶绿体超微结构的影响,为叶片抗衰老技术的研发提供理论依据。研究结果表明:补充红光显著提高了叶片的叶绿素含量、净光合速率、F_v/F_m值和可溶性蛋白质含量,叶绿体基粒片层排列整齐有序,明显减缓了叶绿体超微结构的解体,显著延缓叶片衰老;补充蓝光处理前期显著降低了叶片的叶绿素含量、净光合速率、F_v/F_m值和可溶性蛋白质含量,破坏了叶绿体的超微结构,加速了植株的衰老进程;但在叶片衰老后期,叶绿素含量、净光合速率、F_v/F_m值和可溶性蛋白质含量逐渐高于对照,并且叶绿体的基粒片层比对照排列整齐有序,在一定程度上延缓了叶片衰老。补充蓝光处理的叶片可溶性蛋白质含量一直显著高于补充红光和对照。综上,补充红光处理有效延缓了叶片衰老进程,延长了叶片的生理功能期。  相似文献   
22.
LI Xuemei 《干旱区科学》2020,12(3):374-396
Short-term climate reconstruction, i.e., the reproduction of short-term(several decades) historical climatic time series based on the relationship between observed data and available longer-term reference data in a certain area, can extend the length of climatic time series and offset the shortage of observations. This can be used to assess regional climate change over a much longer time scale. Based on monthly grid climate data from a Coupled Model Inter-comparison Project phase 5(CMIP5) dataset for the period of 1850–2000, the Climatic Research Unit(CRU) dataset for the period of 1901–2000 and the observed data from 53 meteorological stations located in the Tianshan Mountains region(TMR) of China during the period of 1961–2011, we calibrated and validated monthly average temperature(MAT) and monthly accumulated precipitation(MAP) in the TMR using the delta, physical scaling(SP) and artificial neural network(ANN) methods. Performance and uncertainty during the calibration(1971–1999) and verification(1961–1970) periods were assessed and compared using traditional performance indices and a revised set pair analysis(RSPA) method. The calibration and verification processes were subjected to various sources of uncertainty due to the influence of different reconstructed variables, different data sources, and/or different methods used. According to traditional performance indices, both the CRU and CMIP5 datasets resulted in satisfactory calibrated and verified MAT time series at 53 meteorological stations and MAP time series at 20 meteorological stations using the delta and SP methods for the period of 1961–1999. However, the results differed from those obtained by the RSPA method. This showed that the CRU dataset produced a low degree of uncertainty(positive connection degree) during the calibration and verification of MAT using the delta and SP methods compared to the CMIP5 dataset. Overall, the calibrated and verified MAP had a high degree of uncertainty(negative connection degree) regardless of the dataset or reconstruction method used. Therefore, the reconstructed time series of MAT for the period of 1850(or 1901)–1960 based on the CRU and CMIP5 datasets using the delta and SP methods could be used for further study. The results of this study will be useful for short-term(several decades) regional climate reconstruction and longer-term(100 a or more) assessments of regional climate change.  相似文献   
23.
勉有明  李荣  侯贤清  李培富  王西娜 《核农学报》2020,34(10):2343-2351
为探究秸秆还田配施腐熟剂对宁夏扬黄灌区土壤改良和玉米增产的效应,在秸秆还田条件下施用3种不同腐熟剂[生物秸秆速腐剂(SR+BS)、EM菌秸秆腐熟剂(SR+RJ)、有机废物发酵菌曲(SR+OW)],以秸秆还田不施腐熟剂处理为对照(CK),研究其对秸秆生物失重率、砂性土壤理化性状和滴灌玉米生长及产量的影响。结果表明,3种腐熟剂均能有效促进玉米秸秆腐解,其中SR+RJ的秸秆腐解程度最佳,翻埋130 d后其秸秆生物失重率为49.9%,SR+OW和SR+BS次之,3种处理分别较CK显著提高7.1、5.7、5.2个百分点。SR+RJ对改善0~40 cm土层土壤容重效果最佳,较CK显著降低4.2%,同时显著提高了耕层土壤有机质和速效养分含量及生育中后期土壤贮水量,SR+OW和SR+BS次之。施用秸秆腐熟剂能明显促进玉米生育中后期植株生长,其中SR+RJ最佳。SR+RJ和SR+OW对玉米增产增收效果最明显,分别较CK显著增产26.9%、23.4%,显著增收28.8%、23.4%。可见,秸秆还田配施腐熟剂可有效促进玉米秸秆腐解,改善土壤理化性质,促进玉米生长发育,显著提高作物产量与经济效益,以EM菌秸秆腐熟剂效果最佳。本研究为宁夏扬黄灌区还田后促进秸秆腐熟和砂性土壤培肥及玉米高产提供了技术参考。  相似文献   
24.
金花茶对低温胁迫的生理响应及耐寒性分析   总被引:1,自引:0,他引:1  
为探究金花茶幼苗对低温胁迫的生理响应及其耐寒性,本研究以2 a生金花茶幼苗为材料,进行6~-9℃低温胁迫处理,测定了细胞伤害率(CIR)、丙二醛(MDA)、过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、束缚水(BW)/自由水(FW)、脯氨酸(Pro)、可溶性糖(SS)等指标,并进行了低温半致死温度(LT50)和抗寒生理指标相关性分析。结果表明,3~12 h的低温LT50为-6.62~-3.94℃,且随着时间的延长而升高。随着温度的降低, CIR、SS含量及POD、CAT活性总体呈上升趋势, BW/FW、MDA、Pro含量呈先上升后下降趋势, SOD活性总体呈下降趋势;随着胁迫时间的延长,CIR含量呈上升趋势,3~-9℃的SOD活性、0~-9℃的POD活性、-6~-9℃的BW/FW比值呈下降趋势,6~-6℃的SS含量变化较小,-9℃的SS含量呈下降趋势。相关性分析表明,CIR可作为耐寒性鉴定的主要指标,BW、SS、SOD、POD、CAT可作为辅助指标。本研究结果为金花茶引种区域和耐寒性鉴定指标的确定提供了理论依据。  相似文献   
25.
Phytoremediation is a promising approach for reclamation of salt-affected soil. Phytoextraction is the most commonly used process, which exploits plants to absorb, immobilize, and accumulate salt in their shoots. In this study, halotolerant plant growth-promoting rhizobacteria (PGPR) were isolated from the rhizosphere of wild grasses growing naturally in salt-affected areas of Lucknow, Uttar Pradesh (India) and were tested for their efficacies of salt-tolerance and plant growth-promoting (PGP) abilities. Based on 16S rRNA sequences, the most efficient halotolerant isolates possessing PGP traits were identified as Pseudomonas plecoglossicida (KM233646), Acinetobacter calcoaceticus (KM233647), Bacillus flexus (KM233648), and Bacillus safensis (KM233652). Application of these isolates as bio-inoculants significantly (P < 0.05) increased the growth and bacoside A yield of a medicinal plant, Bacopa monnieri (L.) Nash, grown on natural salt-affected soil. The phytoremediation of salt-affected soil was evident by the substantial increase in shoot Na+:K+ ratio of bio-inoculant-treated plants. When compared to un-inoculated control plants, the soil physico-chemical properties of bio-inoculant-treated plants were improved. The shoot and root biomass (fresh and dry weights), soil enzymes, and soil nutrient parameters showed significant positive correlations with the shoot Na+:K+ ratio. Consequently, the halotolerant PGPR screened in this study could be useful for the reclamation of saline soils concomitant with improved plant growth and bacoside A yield.  相似文献   
26.
In this study, sixteen wheat varieties for cultivation in China were examined for the flour characteristics using the farinograph, extensograph and rheofermentometer, uniaxial extensional rheology employing the extensograph and the Kieffer extensibility rig and biaxial extension by uniaxial compression of mixed dough with and without yeast, rested and fermented dough, and steamed bread quality including specific volume and texture properties. Three statistical analysis methods including Pearson correlation, principle component and stepwise multiple regression analysis were carried out to correlate dough properties with steamed bread quality. Biaxial extension viscosity was positively correlated with texture properties (hardness and chewiness) of steamed bread (r = 0.521–0.685, p < 0.05). Based on the correlation coefficients and the model (r2 = 0.852, p = 0.003) obtained using stepwise multiple regression analysis, the best predictors for specific volume of steamed bread were the maximum resistance to extension of rested dough (r = 0.664, p < 0.01) and total work for breakage of fermented dough (r = 0.662, p < 0.01). Principal component analysis of rheological properties of fermented dough and flour characteristics provided more useful information for discriminating wheat flour quality and help breeders to select most convenient wheat flour for the steamed bread making.  相似文献   
27.
The increasing need to prolong the shelf life of buckwheat has prompted the use of roasting techniques in buckwheat processing. For effective roasting, the responses of common buckwheat (CB) and tartary buckwheat (TB) to the process should be explored. Herein, the antioxidant properties, nutrients, pasting, and thermal properties of raw and roasted buckwheat flours (roasted at 200 °C for 50 s) from two CB and three TB varieties were investigated. Results showed that roasting considerably reduced the total flavonoid content (TFC) and total phenolic content (TPC) of TB. The TPC of CB was significantly improved by roasting, whereas the TFC significantly decreased. The total antioxidant capacities were consistent with the TPCs. Additionally, the colour deepened as the amount of antioxidant compounds increased. Unexpectedly, roasting enhanced the protein and fat contents of CB and decreased those of TB. Roasting improved the nutritional quality and antioxidant capacity of CB, and opposite results were obtained in TB. In conclusion, CB was more suitable to the development of roasted specialty products with nutritional applications than TB. We suggest that differences among varieties should be considered first in the buckwheat roasting process.  相似文献   
28.
为分析阴山北麓内蒙古武川县林地持水量和固持水土的能力,以当地柠条、油松、沙棘、油松×柠条混交林、沙棘×柠条混交林5种典型人工林林分类型为研究对象,测定了土壤物理性质、土壤水分入渗以及水分贮存特征值等指标。结果表明:不同林分类型的土壤物理特征存在显著差异(P<0.05)。容重表现为沙棘最大(1.452 g·cm-3),油松最小(1.042 g·cm-3);非毛管孔隙度的排序为油松>油松×柠条混交林>沙棘×柠条混交林>沙棘>柠条。各林分达到稳渗的速率与非毛管孔隙度的排序相一致,各样地的稳渗速率在0.47~1.32 mm·min-1之间,土壤入渗回归方程拟合效果较好。只有油松纯林和油松×柠条混交林更接近考斯加柯夫公式中的系数1/2。混交林地比纯林地对水分的贮存能力高,而油松×柠条乔灌木混交林比沙棘×柠条灌木混交林的最大持水量高112.8 t·hm-2。在阴山北麓地带更适合种植油松×柠条类的乔灌木混交林,乔灌木混交林能更加有效地提高林地持水功能。  相似文献   
29.
为实现对不同类型蜂蜜的特征和质量的科学评价,测定了不同蜜源(洋槐蜜和椴树蜜)和不同结晶状态蜂蜜的主要成分,并利用差示扫描量热技术分析了其热力学性质。结果表明:无论结晶与否,不同蜜源蜂蜜中的葡萄糖和果糖含量均差异显著。相对于椴树蜜样品,洋槐蜜样品的水分活度可能更不利于酵母菌的滋生。玻璃转化温度、放热峰峰温和放热峰焓变等热力学参数,对于区分不同的蜂蜜样品较为灵敏。蜂蜜样品的热力学性质主要受到结晶状态的影响,而与蜜源特征相关性较小。基于以上结果,及时监测蜂蜜的水分活度有助于控制微生物(尤其是酵母菌)的滋生。通过测定蜂蜜的玻璃转化温度、放热峰峰温和放热峰焓变等指标,可以预测蜂蜜的结晶程度。  相似文献   
30.
[目的/意义]目前图书馆文化创意产品的开发还处于探索阶段,关注文化产业中相关新概念的产生能够进一步明确把握文化创意产品的核心,并由此来激活更多的创意表达,助力图书馆对于文化创意产品的理解和开发。[方法/过程]通过从IP到文化IP的概念辨析,阐述文化IP与文化创意产品之间的关系。横向比较同类文化机构,分析得出图书馆文化创意产品现有的开发不足之处。[结果/结论]梳理文化IP对图书馆文化创意产品开发流程的影响及重要性,保证开发过程中文化价值不流失的同时也使整个过程能够形成系统化,提出图书馆需要围绕图书馆文化IP开发文化创意产品的3点建议:持续长线塑造文化IP文创、以联盟优势合作开发文创产品以及助推数字文创和跨界合作。  相似文献   
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