美国豆芋花总皂苷制备及其α-葡萄糖苷酶抑制活性

为高效利用美国豆芋花皂苷类化合物,以皂苷得率和纯度为指标,研究美国豆芋花总皂苷的提取工艺及大孔树脂纯化工艺,并对制备的美国豆芋花总皂苷的抗氧化及α-葡萄糖苷酶活性抑制能力进行研究。结果表明,美国豆芋花总皂苷的提取工艺为提取溶剂90%乙醇,料液比1∶20,温度70℃,提取时间2 h。得到的提取物石油醚脱脂后用水饱和正丁醇萃取,D-101大孔树脂吸附柱纯化的工艺为上样皂苷质量浓度1 mg·m L~(-1),上样量40 m L·g~(-1)树脂,洗脱剂为80%乙醇(pH值6),洗脱剂用量4 BV(树脂柱体积)。制备的美国豆芋花总皂苷样得率4.24%,纯度达65.35%,比粗提物(纯度15.27%)提高了约3倍;抗氧化性能(清除DPPH和ABTS自由基IC50值分别为51.08、29.24μg·m L~(-1))和α-葡萄糖苷酶活性抑制能力(IC50值为83.62μg·m L~(-1))也均优于粗提物(清除DPPH、ABTS自由基IC50值分别为286.51、69.92μg·m L~(-1),α-葡萄糖苷酶的抑制浓度(IC50)值为1 043.57μg·m L~(-1)),表明该工艺可用于高活性美国豆芋花总皂苷的富集和纯化。此外,美国豆芋花总皂苷抑制α-葡萄糖苷酶活性的抑制类型为竞争型抑制,抑制常数为49.68μg·m L~(-1)。本研究结果为开发具有降血糖功能的医药中间体或功能性食品提供了新资源和实践基础。     

有机土配方与生姜产量品质的关系

采用二次饱和D-最优设计,研究了有机土配方对生姜生长的影响,建立了以基质玉米秸秆和速效氮磷钾含量为变量因子,生姜产量和品质分别为目标函数的二元二次数学模型。模型解析表明,玉米秸秆对生姜产量和品质的影响大于速效氮磷钾。在低水平条件下,生姜产量和品质均随着栽培基质中玉米秸秆及速效氮磷钾含量的增加而增加,当氮磷钾含量分别为2588和1468 mg/kg时,生姜产量和品质达到最高值,分别为75.98 t/hm2和88.17;当玉米秸秆含量为41.5%时,生姜产量最高,为82.50 t/hm2,之后,继续增加玉米秸杆和速效氮磷钾含量,则产量逐渐降低;但生姜品质则以玉米秸秆含量为50.0%时最优,为98.02。通过计算机模拟得出,本试验条件下,生姜优质高产有机土配方为:玉米秸秆含量35.6%~46.0%、速效氮磷钾的含量2238～3180 mg/kg。     

不结球白菜BcLBD37基因的克隆及其对硝酸盐吸收的调节

LBD转录因子是高等植物特有的一类转录因子。为研究不结球白菜LBD基因对硝酸盐吸收的影响,以紫色不结球白菜自交系NJZX3-4为材料,采用同源克隆的方法克隆BcLBD37基因;通过构建PRI101过表达载体,异缘转化拟南芥,实现BcLBD37基因的过表达;同时借助病毒介导的基因沉默技术(VIGS),使不结球白菜中的BcLBD37基因沉默;并利用实时荧光定量PCR(qRT-PCR)分析BcLBD37基因过表达以及沉默后对硝酸盐吸收相关基因表达量的影响。结果表明,该基因片段长度为840 bp,编码279个氨基酸。与野生型相比,转基因拟南芥中硝酸盐代谢相关基因NIA1、NIA2、NRT1.1、NRT1.7、NRT2.1、NRT2.5的表达量均显著下调,硝酸还原酶活性和硝态氮含量亦显著降低。而在不结球白菜中沉默该基因后,沉默植株PTY-2/4中硝酸盐代谢相关基因的表达显著上调,硝酸还原酶活性和硝态氮含量亦显著提高。综上可知,BcLBD37基因通过抑制硝酸盐代谢相关基因的表达,调节硝酸还原酶的活性,进而抑制$\text{NO}_{3}^{-}$的吸收。本研究为提高不结球白菜营养品质提供了理论依据。     

秸杆栽培食用菌拮抗菌株的鉴定及混菌发酵条件的优化

从海洋泥样和食用菌发酵料中分离出了32个菌株,从中筛选出了既具有较高的纤维素酶活性又具有对青霉(Penicillium spp)、木霉(Trichoderma spp.)、根霉(Rhizopus)、曲霉(Aspergillus spp)、毛霉(Mucro)较强拮抗能力的W-4、W-10、N-14三个菌株。经鉴定W-4、W-10分别属于放线菌中黄色节杆菌(Arthrobacter flavescens)和石灰壤诺卡氏菌(Nocardia calcarea),N-14属于细菌中的乳酸乳杆菌(Lactobacillus lactis)。通过正交试验对上述3个菌株混合发酵条件进行优化,确定在温度35℃、时间36h、pH7.5、装液量60ml/250ml时为最适发酵条件。在此条件下3个菌株混合发酵液纤维素酶活力仍然很高。同时混合发酵液对青霉、曲霉、毛霉、木霉、根霉的拮抗能力分别为单菌株发酵液的1.79倍、1.36倍、1.29倍、1.04倍、1.07倍。     

Test Analysis on Prestressed Frames with Three Kinds of Beam-column Section Strength

"Strong column with weak beam","strong beam with weak column" and"column & beam with equal strength"can be existed in one-storey prestressed concrete frames and the top storey of mult-storey prestressed concrete frames.Through the test of four prestressed concrete frames under vertical load,three kinds of prestressed concrete frames performances are studied,such as ultimate load,deflection,displacement ductility,redistribution of internal force.When the relative height of equivalent compression zone is smaller enough,the test proves that three kinds of prestressed concrete frames can realize full redistribution of internal force and have better displacement ductility,the width of cracks and deflections can satisfy the rules of code for design of concrete structures.     

Discussion on the Integration of the Channels for the Sale Promotion of Real Estate

Based on the theory of value chain,this paper explained the constitution of the value chain and the important function of channels in Real Estate sale promotion.Furthermore,it analyzed the erroneous ideas about the present management of the channels for sale promotion systematically.And for the lower-cost and high-efficiency purpose,it puts forward the viewpoint that channels should be established and integrated based upon the value chain theory,moreover,the key point in the process was discussed.     

供铁水平对不同苹果基因型生长及根系特性的影响

以小金海棠 (MalusxiaojinensisChengetJiang)和山定子 (MalusbaccataL .Borkh)为试材 ,研究供铁水平对其生长及根系特性的影响 ,结果表明 ,在幼苗生长量、新叶叶绿素含量、营养液pH日变化、根系活力、根系ATP酶活性诸方面 ,存在基因型差异。同一供铁水平 ,小金海棠有明显的铁胁迫反应 ,而山定子铁胁迫反应较弱。低铁胁迫处理 ,小金海棠叶片叶绿素含量、根系活力、根系ATP酶活性皆明显高于山定子。根系活力及根系ATP酶活性可用作铁高效基因型植物的筛选指标     

枯草芽孢杆菌CN620菌株制剂对板栗烂果病的防治及病原的抑制作用初报

从板栗树体上分离得到枯草芽孢杆菌 [Bacillussubtilis(Ehrenberg)Cohn]CN62 0菌株。室内测定其菌株制剂对Glomerellasp .、Alternariaalternata、Trichotheciumroseum、Pestalotiasp .和Fusariumsp .5种板栗烂果病主要病原的抑制作用均为 1 0 0 % ,而CN62 0菌株 50倍培养液 ,对上述 5种病菌的抑制效果为 86.5%～ 96.6%。其抑菌机理主要是使病菌孢子和菌丝畸变 ,细胞壁溶解 ,原生质泄漏。 1 997年和 1 998年连续两年两点对板栗烂果病进行小区防治试验的防治效果分别为 87.7%和 87.6% ,明显高于化学农药处理的 30 .4 %和 31 .7%的效果     

Effects of planting methods on yield and quality of different types of japonica rice in northern Jiangsu plain,China

Mechanical transplanting with carpet seedlings (MC) and mechanical direct seeding (MD) are newly developed planting methods, which increase in popularity and planted area each year. Knowing the difference for yield and rice quality under different planting methods is of great importance for the development of high quality and yield cultivation techniques under mechanical conditions. Therefore, three kinds of japonica rice including hybrid japonica rice, inbreed japonica rice, and soft rice were adopted as materials. And the differences in the quality of processing, appearance, cooking and eating quality, nutrition, and the rapid viscosity analyzer (RVA) profile were studied to reveal the effects of planting methods on yield and quality of different types of japonica rice. Results showed that the milled rice and head rice rates under MC was significantly higher than those under MD, and the processing quality of inbreed japonica rice was the most stable. Compared with MC, length/width ratio of rice under MD was significantly increased, and chalkiness rate, size, and degree were significantly decreased. The protein content under MD was lower than that under MC. MC showed higher peak viscosity and breakdown value than MD. The taste value was the greatest for soft rice, followed by inbreed japonica rice, and then by japonica hybrid rice, with no significant differences resulting from planting methods. Compared with MC, MD significantly improved the appearance quality, though processing quality and nutritional quality were decreased. And there was no significant difference in cooking and eating quality between MC and MD. Under different planting methods, the appearance quality of inbreed japonica rice changed the most and the processing quality was the most stable. The nutritional, cooking and eating quality of soft rice changed the least. Therefore, according to the different planting methods and market needs, selecting the appropriate rice varieties can reduce the risks in rice production and achieve good rice quality.     

保健型柚类新品种——马家柚

马家柚是1980年代中期,在江西省广丰县大南镇马家自然村地方柚群体中选出的实生变异。该品种果大、囊红、优质、丰产、抗冻、耐贮,适应性强,果实中富含对人体有重要保健价值的番茄红素。1991年在江西省柚类鉴评会上被评为全省地方柚类第一名,2009年由江西省农作物品种审定委员会审定命名,同年被国家柑桔育种中心选入果树品种资源库。目前已在我国南方诸省推广栽植3 600 hm2。