Relevance of Osmotic and Frost Protecting Compounds for the Winter Hardiness of Autumn Sown Sugar Beet

The cultivation of autumn sown sugar beet (winter beet) is supposed to result in a marked yield increase compared with spring sown sugar beet. Although the importance of the growth stage reached before winter for the survival of autumn sown sugar beet has already been shown, it is not clear to which extent osmotic and potentially frost protecting compounds may contribute to winter hardiness. The study thus aimed to analyse the acclimatization process of sugar beet to low temperatures and to identify compounds which are important for survival of frost. Field trials with autumn sown sugar beet were conducted at eleven environments in Germany from 2009/10 to 2012/13, which were accompanied by greenhouse experiments with controlled temperature regimes. In the field trials, the survival rates after winter varied from 0 % to 99 %, but only in four environments differences between the five genotypes occurred. During acclimatization, betaine, glutamine, proline and raffinose were markedly accumulated and osmolality was enhanced. In particular betaine, amino acids and osmolality showed a positive correlation to the survival rate and were thus identified as potentially frost protecting substances for sugar beet. In contrast, raffinose and proline seem to act rather as stress indicators as they were negatively related to survival. Possible frost protecting substances were identified which can be used in breeding to improve the winter hardiness of sugar beet.     

传统山西老陈醋增香酵母菌的筛选及其特性研究

为选育山西老陈醋用微生物发酵剂,从传统发酵工艺生产的山西老陈醋中分离筛选到5株增香酵母菌。结合形态学和酵母菌26S rDNA Dl/D2区序列分析,初步鉴定Y1为酿酒酵母(Saccharomyces cerevisiae),Y26为毕赤酵母(Pichia scaptomyzae),Y30为假丝酵母(Candida humilis),Y68为红酵母(Rhodotorula sp.),Y70为盔形毕赤酵母(Pichia membranifaciens)。采用固相微萃取和气-质联用技术分析这5株酵母发酵液的主要挥发性成分。结果表明,醇类和酯类挥发性成分种类和组成差异较大;对这5株酵母菌进行耐酸性、乙醇耐受性、高温耐受性发酵试验,结果表明毕赤酵母Y26具有优良的耐酸性、乙醇耐受性。综合其具有高产乙酯类、低产高级醇的特性,毕赤酵母Y26有望开发为山西老陈醋的新型发酵剂。     

Productive and biochemical responses of durum wheat to UV filtration

A UV exclusion experiment was conducted on durum wheat (Triticum durum Desf. var. Claudio) grown in pots. Plants were grown under three different radiative treatments in greenhouses covered with plastic filters: Teflon, transparent to the entire region of natural UV‐visible sunlight (TEF); polyester, transparent above 312 nm (MYL, excluding UVB) and Lee, transparent above 400 nm (LEE, excluding both UVA and UVB). Analyses have been carried out to determine the concentration of photosynthetic pigments in leaves, UV‐absorbing compounds, nitrogen and carbon in leaves, culms and spikes and proteins and gluten in grains. In particular, plants grown under UV exclusion showed a reduction in protein and dry gluten content (consequently without variation in the ratio dry gluten/protein), but at the same time, a significant increase of gluten index, which is a parameter to define the quality of gluten, was observed. The results highlighted the influence played by UV radiation on some biochemical parameters, mainly UV‐absorbing compounds, leaf nitrogen and grain protein characteristics of durum wheat cultivated under Mediterranean conditions. In particular, natural level of UV in the Mediterranean improves the characteristics of durum wheat flour important for pasta production (high dry gluten level), while the UV exclusion could improve characteristics of flour important for bread production (high gluten index).     

鸡粪及其配施尿素对甜瓜香味物质、酶活性及基因表达的影响

为了探讨鸡粪以及鸡粪与尿素配施对薄皮甜瓜果实香气物质合成及关键酶的影响,以薄皮甜瓜"DX108"为试材,以尿素为氮源的处理作为对照(CK),研究等量氮素条件下,鸡粪及其与尿素配施处理对甜瓜果实香气物质以及相关酶活性变化的影响,并分析了乙醇脱氢酶(ADH)和醇酰基转移酶(AAT)基因的表达水平。结果表明:不同处理对薄皮甜瓜香气物质合成、相关酶活性以及关键酶基因表达的影响存在明显差异;尿素处理促进了甜瓜果实中C6和C9醇醛类化合物的合成,而鸡粪以及鸡粪与尿素配施提高了成熟果实中酯类物质含量和种类,尤其是乙酸酯类含量;鸡粪配施尿素处理提高了花后35 d甜瓜果实中非乙酸酯类物质含量,且是尿素处理花后35 d甜瓜果实中非乙酸酯类物质含量的3.1倍,还检测到了尿素处理果实中没有检测到的特征性酯类物质;鸡粪和鸡粪配施尿素处理提高了花后25～30 d果实中LOX酶、氨基转移酶、ADH酶以及AAT酶活性,降低了花后35 d果实中ADH酶活性,抑制了30 d后果实中CmADH1和ADH2的基因表达,而促进了CmAAT1和CmAAT3基因表达。由此可知,鸡粪以及鸡粪与尿素配施有可能是通过调节果实不同发育期香味物质合成途径中关键酶活性的协调变化以及关键酶基因表达,影响了果实香气物质的合成,尤其是酯类物质的合成。     

不同基因型菠萝蜜种质资源挥发性香气成分分析

以马来西亚1号菠萝蜜、XYS17菠萝蜜、XYS18菠萝蜜和榴莲蜜为材料,采用HS-SPEM-GC-MS进行测定分析,以期揭示不同基因型菠萝蜜资源香气成分组成差异,为资源创新利用提供理论依据。结果表明：4种不同基因型菠萝蜜资源共鉴定出66种香气物质,异戊醇、月桂醛、3-甲基丁酸-2-甲基丁酯、乙酸异戊酯、异戊酸丙酯等9种共有香气成分相对含量存在极显著差异。PCA分析表明,马来西亚1号主要香气成分为3-甲基丁酸戊酯、乙酸丁酯、乙酸异戊酯、异戊酸丁酯和3-甲基丁酸-2-甲基丁酯,XYS17主要香气成分为异戊酸丁酯、3-甲基丁酸-2-甲基丁酯、3-甲基丁酸戊酯、醋酸辛酯和癸醛,XYS18主要香气成分为异戊酸乙酯、异戊酸丁酯、丁酸乙酯、异戊酸甲酯和正辛醛,而榴莲蜜主要香气成分为异戊醇、2-甲基-1-丁醇、3-甲基丁酸-2-甲基丁酯、异戊酸乙酯和异戊酸异戊酯。不同基因型菠萝蜜香气成分物质组成及含量存在一定差异,为今后新品种选育和优异资源开发利用提供参考依据。     

4份桃种质挥发性成分的GC-MS分析

为了分析桃果实中共有的挥发性成分及初步探讨果皮毛和果肉颜色性状对挥发性成分的影响情况,以此2对性状均存在差异的4份桃种质为试材,采用顶空固相微萃取方法提取其成熟果肉中的挥发性成分,并用气相-质谱联用仪对其进行了测定。结果表明:4份桃种质中共鉴定出116种挥发性成分,其主要为酯、醛、醇和烷烃等类物质。从挥发性成分的种类数量上看,白肉桃‘大久保’和‘华光’中检出的挥发性成分种类较多,分别有68和52种;而2份黄肉桃种质中检出的挥发性成分种类均较少。从挥发性成分的种类上看,2份普通桃与2份油桃中的差异挥发性成分总共仅有3种,其分别为反式-2,4-庚二烯醛、戊酸-2,2,4-三甲基-3-异丙酸-异丁酯和脱氧精胍菌素,远低于2份白肉桃与2份黄肉桃种质中差异挥发性成分的数量(13种)。此外,从挥发性成分的类群上看,2份白肉桃含有较多的"青香型"的C6类化合物,而2份黄肉桃含有较多的"果香型"的酯和内酯类化合物。文中综合分析认为,果皮毛的有无和果肉的颜色性状均可能影响果实中挥发性成分的数量和种类,但后者的影响较为明显。     

Nutritive value of sorghum silage for sheep

This study compared ensiled sorghum (ES) from two varieties (first and second cuts) with corn silage (CS) for chemical analysis, total-tract nutrient digestibility, ruminal variables and blood biochemistry metabolites in sheep. Five experimental silages representing first cut ES var. Pegah (PS1), second cut ES var. Pegah (PS2), first cut ES var. Speedfeed (SS1), second cut ES var. Speedfeed (SS2) and CS were assessed for chemical analysis, silage fermentation and anti-quality compounds. Diets consisted of lucerne hay, silage and a premix (at the ratio of 53.5:46:0.5 on a dry matter [DM] basis). Feed consumption, total-tract nutrient digestibility, microbial nitrogen supply (MNS), ruminal variables and blood biochemistry metabolites were determined in a Latin square design of five periods with five male sheep. Compared to sorghum, CS had lower (p < 0.01) concentrations of ash, water-soluble carbohydrates and crude protein, but higher starch, lignin (sa), non-structural carbohydrates and apparent nutrient digestibility. The measurements of pH, lactic acid, NH₃-N and volatile fatty acids (VFA) confirmed that all silages were well-preserved. The anti-quality compound levels in the silages were below the safe limits for ruminants. No differences were observed in feed consumption (p > 0.05) and total-tract digestibility of DM and nutrients (p > 0.05). Rumen pH, NH₃-N, VFA concentrations and acetate to propionate ratio showed no difference among treatments (p > 0.05). Sheep fed on sorghum silage showed a decrease (p < 0.01) in total protozoa, and particularly in the Entodiniae population. There were no differences in cellulolytic bacteria counts (p > 0.05) among treatments. Urinary N, MNS and blood biochemistry metabolites showed no difference among treatments (p > 0.05). Silages from both cuts of sorghum had comparable total-tract nutrient digestibility to CS, therefore, these varieties could be used as a more drought resilient silage source in the feeding of sheep.     

SPME-GC/MS联用技术比较分析不同品种蜜柚柚花的香气成分

【目的】了解不同品种蜜柚柚花的香气成分差异,为柚花的加工利用提供参考。【方法】采用固相微萃取结合气相色谱-质谱联用分析法,对各成分质谱通过计算机谱库检索和资料分析,鉴定与比较分析了白肉蜜柚、红肉蜜柚、三红蜜柚、黄金蜜柚4种柚花的香气成分。【结果】从柚花中共检测出36种香气成分,4个品种柚花中分别为17、19、23、17种。柚花中香气成分主要均为芳樟醇,其中白肉蜜柚柚花中芳樟醇相对含量最高,达到68.65%,黄金蜜柚柚花含量次之,为67.43%,而红肉蜜柚和三红蜜柚柚花中芳樟醇含量相当,分别为65.01%和64.50%。三红蜜柚花朵的香气组成物质与其他三种比较,区别较大,萜烯类物质丰富,而酯类和烷烃类物质则较少。总之,本文初步从香气成分种类差异、共有香气成分相对含量差异以及各自特有成分上解释了4种柚花香气的区别,并分析和展望了柚花的应用前景。     

软儿梨冷冻贮藏过程酚类物质与多酚氧化酶的区域化分布

为研究冷冻贮藏中不同部位酚类物质和多酚氧化酶的分布特征,以青海省地方梨优良品种‘软儿梨’果实为研究材料,采用高效液相色谱法和比色法测定软儿梨果实后熟(室温)、冻藏(-18℃)和解冻(室温)3个时期的果皮、果肉中总多酚、绿原酸的含量和多酚氧化酶活性。结果表明:软儿梨果实后熟后,酚类物质果肉?果皮,多酚氧化酶则果皮?果肉;冷冻贮藏过程中,不同部位的酚类物质和多酚氧化酶均呈现不同程度的升高,但绿原酸在果皮急剧下降、果肉中略有增加。解冻后总体呈下降趋势,2个部位总酚、多酚氧化酶下降明显,而果皮中的绿原酸变化不大。研究表明:软儿梨果实后熟后,酚类物质和多酚氧化酶分布呈现区域化,冷冻贮藏加剧了酚类物质和多酚氧化酶活性的积累,导致了软儿梨冷冻贮藏后果皮先于果肉发生了褐变。