适用于转录组测序的大豆根总RNA的提取方法研究

[目的]获得高质量、高产量并能满足转录组测序要求的大豆根总RNA。[方法]比较分析了Trizol法、CTAB-Li Cl法和试剂盒法的提取效果。[结果]3种方法均能从大豆根中提取出总RNA。但与Trizol法、CTAB法相比,试剂盒法提取的大豆根总RNA纯度高、完整性好,平均浓度达413.9 ng/μL,A260/A280≈2.14,A260/A230≈2.10,方法可重复性好。[结论]试剂盒法提取的RNA满足转录组测序的质量要求,可进行后续的转录组测序和其他分子生物学相关研究工作。     

玉米须总黄酮提取工艺及其降血糖作用研究

[目的]研究玉米须总黄酮提取工艺及降血糖作用。[方法]以玉米须为材料,通过正交设计考察乙醇浓度、料液比、提取时间对玉米须总黄酮提取率的影响,确定最佳工艺条件;并以四氧嘧啶所致糖尿病小鼠为动物模型,研究玉米须提取物的降血糖作用。[结果]玉米须总黄酮提取最佳条件为16倍70%乙醇,回流2次,每次浸提2 h。动物试验表明,玉米须提取物高剂量组能显著抑制四氧嘧啶所致糖尿病小鼠模型血糖的持续升高(P0.05)。[结论]玉米须提取物具有辅助降血糖作用。     

正交试验优化提取壮药马尾千金草生物碱

[目的]优化马尾千金草生物碱的提取条件。[方法]以马尾千金草的总生物碱含量为指标,运用正交试验设计对酸水浓度、料液比、浸提次数3个因素进行考查,优化最佳提取工艺。[结果]酸水浸泡提取的最佳条件为加入10倍的1%酸水液,浸泡提取3次,每次24 h,生物碱得率为0.0751%,马尾千金草生物碱含量为7.51 mg/g。[结论]该提取方法操作较简单、成本低、生物碱得率高,能有效提取马尾千金草总生物碱。     

佳木斯市郊区不同土地利用方式下土壤微生物多样性

[目的]测定不同土地利用方式下微生物的多样性及与p H、有机质含量、含水量、总磷含量的关系,探究佳木斯市郊区不同土地利用方式对土壤微生物的影响.[方法]通过稀释涂布平板法测定微生物数量,重铬酸钾氧化法测定有机质含量,硫酸-过氧化氢消煮紫外分光光度法测定总磷含量.[结果]菜地微生物总数、有机质含量、总磷含量、p H及含水量均高于田地.[结论]不同土地利用方式对微生物多样性的影响不同,减少化肥的使用,增施有机肥是实现土地资源可持续利用的重要途径.     

中式凉菜多味苦瓜的最佳食用时限研究

[目的]研究4℃冷藏时自制凉菜多味苦瓜微生物菌群构成和卫生质量控制技术。[方法]以苦瓜为主料,加入葱、泡红辣椒、豆瓣酱、香醋等调配料经拌匀制成多味苦瓜,分析其细菌数来源。[结果]凉菜中细菌有86.51%来自豆瓣酱,6.98%来自葱,5.30%来自苦瓜,0.92%来自泡红辣椒,对苦瓜、葱、姜进行2 min热烫处理,大蒜进行3 min热烫处理,对泡红辣椒、豆瓣酱进行高压灭菌20 min处理后,减菌率分别为97.5%、99.7%、97.9%、99.9%、99.8%和99.9%。该类食品中的优势菌为假单胞菌和乳酸菌,在4℃放置的保质期由3 d增至5 d,表明其具有应用价值。[结论]研究可为中式凉菜的卫生质量控制提供参考。     

正交试验优化腌制芥菜发酵工艺及调控亚硝酸盐含量的研究

[目的]优化芥菜腌制发酵工艺,控制腌制芥菜亚硝酸盐含量。[方法]以芥菜为原料,以亚硝酸盐含量、感官评分为指标,采用正交试验设计,优化芥菜腌制发酵工艺的生产方法;以亚硝酸盐含量、亚硝峰峰值的抑制率为指标,采用单因素试验法,确定异抗坏血酸钠、EDTA-2Na、藠头及柠檬酸对亚硝酸盐含量的调控作用。[结果]在乳酸菌接种量5%、食盐添加量5%~7%(取6%)、温度30℃、发酵9 d的工艺条件下,腌制芥菜中亚硝酸盐含量为0.74 mg/kg,远低于国家标准规定的20 mg/kg的标准,所得的腌制芥菜风味可口。异抗坏血酸钠和藠头能有效抑制亚硝峰的峰值及降低成品中亚硝酸盐含量,而柠檬酸和EDTA-2Na仅能有效抑制亚硝峰的峰值,不能有效降低成品中亚硝酸盐含量。[结论]研究可为腌制芥菜的开发利用提供技术支撑。     

A study of biodiversity of flavonoid content in the rice caryopsis evidencing simultaneous accumulation of anthocyanins and proanthocyanidins in a black-grained genotype

Rice genotypes with pigmented caryopses have received increased attention because of their antioxidant properties. Previous works evidenced that the kernel of red rice is characterized by the presence of proanthocyanidins, whereas black rice is characterized by the presence of anthocyanins. In the present study, the total antioxidant capacity (TAC) and the polyphenol content of the caryopsis were evaluated on a set of Italian rice varieties (three white, two black and five red ones). The pigmented rices, on average, had a TAC four times higher than the white ones. As expected, red-grained genotypes contained no detectable anthocyanins and one black rice contained no detectable proanthocyanidins. However, the black-grained cv. Artemide had large amounts of both proanthocyanidins and anthocyanins. This genotype was also characterized by the highest TAC and polyphenol content: its TAC was about twice the TAC of the other pigmented rices, and it had a polyphenol content 2–3 times the content found in the other pigmented rices. Pigmented genotypes are confirmed to be very interesting to breed rice for high polyphenol content and TAC. Furthermore, the possibility to select for genotypes accumulating both anthocyanins and proanthocyanidins provides a way to substantially increase the polyphenol content and TAC of the rice caryopsis.     

Pseudocereals as alternative sources for high folate content in staple foods

Total folate content was determined in the pseudocereals amaranth (four varieties), quinoa and buckwheat in comparison to four cereal species (eight wheat varieties, four barley varieties, one oat variety, one rye variety). Amaranth and quinoa were found to possess very high total folate contents: in amaranth, total folate ranged from 52.8 to 73.0 and in quinoa it was 132.7 μg/100 g dm, about ten times as much as in wheat. The bran fractions contained on average 124% of total folate, while only 57% on average was present in the flour fractions.     

铅对芫荽种子萌发及幼苗生长的影响

主要研究铅胁迫对芜荽种子萌发、幼苗生长、叶绿素含量、还原糖、总糖、可溶性蛋白和超氧化物歧化酶(SOD)、过氧化物酶(POD)活性等的影响,初步探讨铅胁迫对芜荽的毒害机理。可为预防重金属对农作物的毒害、提高污染土壤上植物生长的安全性和环境监测中对重金属污染的评价提供一定的依据。     

有机水稻施用有机肥控制杂草技术的研究

本研究利用有机水稻栽培普遍施用的发酵鸡粪,采用不同使用时期和不同施用量的方法进行水田杂草控制试验。结果表明:发酵鸡粪能够有效控制杂草的发生;并且控制杂草效果,分施两次比一次性施用效果好;水稻产量也是施用两次比施用一次高。