喷钛对甜叶菊糖苷含量和积累量的影响

为探索喷钛对甜叶菊叶片中糖苷、甜菊苷(St)和莱鲍迪苷A(RA)的含量、积累量及其比例的影响,为中药材的施肥提供科学依据,应用盆钵培养方法,在甜叶菊生长前期和中期进行叶面喷钛。结果表明:菊隆5号的最佳喷施区间12.22~19.36 mg·kg-1,在喷钛浓度为19.36 mg·kg-1时含量达到最高;新品种2号的最佳喷施区间为12.10~16.71 mg·kg-1,在喷钛浓度为16.71 mg·kg-1时含量达到最高;喷钛后新品种2号St所占比例的最高增幅为156.71%,菊隆5号St的最高增幅为42.28%。喷钛可明显提高糖苷含量和积累总量,与对照相比,差异显著;经回归发现糖苷含量或积累量与喷钛浓度间存在二次曲线关系,相关极显著;喷钛可以增加2个品种糖苷中St的比例。     

甜菊甙提取新工艺研究

用水溶剂低温流动循环法浸提甜菊甙,简便易行,成本低廉。其白色针状晶型产品,提取率为干叶的5％,甜度为蔗糖的200倍以上;淡黄色粉末状晶型产品提取率为10%,甜度为蔗糖的120倍左右。两种产品甜味纯正,无异杂味,生产成本比相同甜度的蔗糖分别低46.0%和59.3％。     

Productivity of two stevia varieties under reduced irrigation and fertilization inputs

A 3-year field study was conducted in central Greece to determine the productivity of two stevia [(Stevia rebaudiana (Bertoni) Bertoni] varieties (‘Morita’ and ‘Candy-stevia’) under normal and reduced irrigation (100% and 75% of the evapotranspiration) and fertilization [1:0.8:1.1 or 1:0.4:0.8 N:P:K ratio in the first year and only N fertilization (100% or 74% of the recommended rate) in the second and third years] inputs. Averaged across years, stevia cv. Morita achieved greater dry leaf yield (3.48 t ha^?1) than the cv. Candy-stevia (2.85 t ha^?1). Irrigation and fertilization inputs did not significantly affect stevia cv. Morita dry leaf and steviol glycosides (stevioside plus rebaudioside-A) yields; however, decreasing irrigation and fertilization caused slight reduction of cv. Candy-stevia yields. In cv. Morita leaves, the concentrations of stevioside and rebaudioside-A ranged from 5.97% to 7.78% and 3.73% to 4.79%, respectively, while the corresponding concentrations in cv. Candy-stevia leaves were 8.21–9.36% and 3.89–6.33%. Conclusively, both stevia varieties could achieve satisfactory dry leaf biomass and steviol glycosides yield, even when grown under reduced irrigation (at 75% of evapotranspiration) and reduced N fertilization (74% of the recommended rate). Thus, stevia could represent an alternative crop to tobacco in the Mediterranean conditions.     

甜菊糖甙对哺乳仔猪生产性能和健康状况的影响

为研究天然甜菊糖甙作为新型甜味剂在哺乳仔猪中的应用效果,随机选取16窝哺乳仔猪(杜长大,10头/窝)分为4组,每组4个重复,分别饲喂添加0、100、200和500g/t天然甜菊糖甙的教槽料,试验从仔猪7d时开始,至断奶后1周(28d)结束,期间每隔7d对仔猪采食量、增重和健康状况进行测定。结果发现,在哺乳仔猪日粮中添加100、200和500g/t的甜菊糖甙,显著提高仔猪断奶重(21d)和28d体重(P0.05),显著提高14～21和22～28d阶段内的平均日增重、平均日采食量和偏嗜指数(P0.05),而各甜味剂添加组间无显著性差异(P0.05)。7～28d内仔猪日增重200g/t组显著高于对照组和100g/t组。仔猪断奶(21d)后1周内腹泻率和腹泻指数有改善趋势(P0.05),7～28d内仔猪发病率200和500g/t天然甜菊糖甙组显著降低(P0.05)。因此,考虑成体投入的同时,在哺乳仔猪日粮中添加200g/t的天然甜菊糖甙,可取得良好的应用效果。     

葡萄糖苷转移酶作用对甜叶菊糖苦味改善的效果和机理研究

为了减少甜叶菊糖的苦涩味,利用葡萄糖背转移酶对甜叶菊糖进行适当程度的酶解试验.结果表明:在浓度为2mg·mL~(-1)的125mL甜叶菊糖溶液中加入葡萄精苷转移酶2 μL,600℃水浴中振荡酶解2h,甜叶菊糖溶液的苫涩味得到明显改善.利用高效液相色谱法测定酶解前后甜叶菊糖结构变化,通过比较可知,甜叶菊糖酶解后有一定量的葡萄糖生成.     

简易HPLC法测定甜菊叶中甜菊糖苷

一般甜菊叶中甜菊糖苷的HPLC检测样品处理复杂,采用简易超声波水提取法处理样品,建立快捷分析方法。甜菊糖苷在300~1500μg/mL内呈线性关系,相关系数为0.9998,平均加标回收率98.32%,相对标准偏差0.63%。该方法操作简单、重复性好、稳定性好、灵敏度高,可为甜菊叶中甜菊糖苷的测定提供参考。     

The effect of different nitrogen levels on yield and quality of stevia (Stevia rebaudiana bert.)

In the present work, the efficiency of different nitrogen doses (0, 50, 100, 150, and 200 kg ha^?1) on growth, yield, and quality of stevia (Stevia rebaudiana Bert.) was investigated in 2011–2013. The study was conducted in Antalya located in the Mediterranean Region of Turkey. Terra rossa type soil (LVx, FAO) characteristics of the experimental field were clay loam, with high amounts of lime (33,9%) and slightly alkaline (pH 7.7). The experiment was carried out in randomized block design with four replications. All the results were summarized as mean of three years. The highest fresh and dry biomass yields (26.75 t ha^?1 and 7.5 ha^?1, respectively) were obtained from 150 kg ha^?1 N dose and followed by 100 kg ha^?1 N dose (26.29 t ha^?1 and 7.24 ha^?1, respectively). Whereas the highest fresh and dry leaf yields (13.27 t ha^?1 and 3.82 t ha^?1, respectively) were realized in 100 kg ha^?1 N dose. Actually, all nitrogen doses gave higher biomass and leaf yields compared to the control. On the hand, major steviol glycosides (stevioside and rebaudioside A) in the leaf were not influenced by nitrogen levels. In conclusion, 100 kg ha^?1 N dose was found to be suitable for cultivation of stevia under field conditions.     

甜叶菊新品系的主要农艺性状及糖苷含量比较

[目的]对4个甜叶菊品系的主要农艺性状、茎叶产量及糖苷含量进行比较,为不同用途的甜叶菊育种提供一定的依据。[方法]对SR-1,SR-2,SR-3和SR-5共4个甜叶菊品系的株高、茎节长、一级分枝数、叶长、叶宽、叶长宽比和茎叶干重等进行考察,采用HPLC法测定其干叶ST和RA糖苷含量,并分析了各性状间相关关系。[结果]4个品系间植株形态、茎叶产量及糖苷品质均存在显著差异,ST苷含量和茎叶产量最高的品系为SR-5,RA苷含量和RA/ST值最高的品系为SR-2,综合RA苷含量和茎叶产量考虑,RA苷总量最高的为SR-3。茎叶产量同株高、茎节长、叶宽间相关显著。RA苷含量与干叶产量、干茎产量及茎叶总产量等呈显著负相关。ST苷含量则与各农艺性状间相关均不显著。[结论]提高甜菊的产量会一定程度影响甜叶菊的品质,但仍有可能选出既高产,品质又符合生产所需的优良甜叶菊新品种。SR-5品系可作为较好的药用型甜叶菊品系,SR-2可用作糖用型甜叶菊育种材料。     

适宜西北地区栽培的甜叶菊品种引种研究初报

为筛选优良甜叶菊品种在西北地区推广栽培,从江苏、安徽、河北等地引进了14个甜叶菊品种进行引种栽培比较研究。结果表明:不同品种间糖苷、干叶产量和茎秆产量差异显著,从安徽引进的甜叶菊品种ZY-0911对西北地区的微碱性土壤有较强的适应性,其甜叶菊糖苷含量和干叶产量都明显高于其它参试品种,分别比平均高出22.54%和9.68%,具有大面积推广栽培的潜力。     

赤霉素对不同甜叶菊品系主要农艺性状、糖苷含量及产量的影响

喷施不同浓度的赤霉素（GA）于4种不同类型的甜叶菊品系叶表面,考察外源激素处理对其主要农艺性状、糖苷含量及糖苷产量的影响。结果表明：（1）赤霉素处理组同对照组相比,处理后株高、节长显著增长,且节间伸长效果主要集中在茎秆中部,叶长显著变短、叶宽显著变窄,叶长宽比值增大,单株干叶产量下降;赤霉素处理间,表现出一定的浓度效应,即随着赤霉素处理浓度增大,表现出一定的株高增加,叶长、叶宽减小的趋势。（2）就提高植株糖苷含量而言,100 mg/L的GA处理（A1）提高了SR1型甜叶菊的RA苷的含量,100 mg/L和300 mg/L GA提高了SR3品系ST苷含量,300 mg/L GA提高了SR2品系ST苷含量。（3）就糖苷产量而言,由于各处理下其干叶产量均显著下降,最终导致所有GA处理中,除300mg/L的GA处理显著提高了SR2的ST苷产量外,其余GA处理均不利于甜叶菊RA或ST糖苷产量的提高。