不同大豆品种出苗后子叶面积及生理指标的变化

运用嫁接体系,以黄淮海地区不同年代生产上大面积种植的品种做砧木,大豆新品种中黄39为接穗。嫁接时砧木处于出苗期（Vc）,保留子叶;接穗处于单叶展开期（V1）,去除子叶和第1对真叶（单叶）。接穗插接于砧木子叶之间。嫁接体成活后至第一三出复叶展开（V2）期间,分期测定子叶面积的变化。同时以百粒重不同的3个大豆品种为材料,设置子叶遮光与正常光照处理,研究了大豆出土后子叶的生长动态及子叶对植株幼苗生长发育的影响。结果表明,不同大豆品种出苗后子叶面积均有增加,但增加幅度不同,最高的可达209．29％,最低的仅有65．61％;Vc-V2期子叶面积的增加幅度与VC期子叶面积负相关;不同年代大豆品种子叶面积在出苗后的增幅随育成年代推后呈现下降趋势。出苗9d后子叶面积、子叶中叶绿素a含量、叶绿素总量、子叶干重随着出苗后天数的增加不断下降;叶绿素b含量则呈现先上升后下降的趋势,而可溶性糖含量先下降后上升,继而随着子叶衰老逐渐下降。对子叶进行遮光处理后,子叶面积、干重、叶绿素a含量、叶绿素b含量、可溶性糖含量的变化幅度变大,表明子叶的“源”功能受限时,其叶绿素的合成与降解、可溶性糖的合成、降解与转运、子叶面积及干重均受到影响。去除子叶使得株高变矮、发育进程变慢、幼苗干重下降,其对幼苗生长发育的影响随子叶摘除时间的推后逐渐减小。说明大豆出苗后子叶是植株的重要营养器官,在栽培管理中应加以保护和利用。     

用于大豆根冠关系研究的嫁接方法

用三个品种（中黄30、中黄39和翼豆12）研究幼苗期不同插接方式对大豆成活率和缓苗天数的影响,以期建立可用于大豆根冠关系研究的嫁接技术.试验采用插接法.对砧木保留两片子叶时接穗去留子叶对成活率的影响,以及接穗保留子叶时,砧木去留子叶对成活率的影响进行研究.结果表明：插接法的成活率可达90％以上;砧木留子叶＋接穗去子叶的嫁接方法缓苗天数需要3～4d;砧木留子叶时,接穗去留子叶对嫁接成活率不会产生显著影响;接穗留子叶时,嫁接部位的不同（即砧木去留子叶）对嫁接成活率没有显著影响;砧木留子叶＋接穗不留子叶的嫁接方式具有一定优势.     

离子注入对烟草种子萌发及苗期生长发育的影响

用不同剂量的氮离子注入ＮＣ８９烟草种子,研究其对种子萌发和苗期生长发育的影响。结果表明,离子注入不同剂量对烟草种子萌发和苗期生长有不同的作用。在２０～１２０次范围内可提高种子前期萌发,促进子叶平展和胚根生长,提高幼苗生理活性,增加干物质积累,其中以８０次最佳;对烟苗叶片长、宽、茎粗的增长及干物质积累都有促进作用,与对照比较都达到显著水平,有些达到极显著水平;对烟苗出叶速率、根长、根幅、侧根数的影响,多数处理有促进作用,其中表现较好的处理有１６０次,４０次,８０次。     

降低食用香椿中亚硝酸盐含量的研究

香椿叶可直接食用或烹调菜肴。味道鲜美,深受国内大部分城乡居民喜爱。对其亚硝酸盐的含量李晓明等人已进行过检测。但是,如何降低香椿中亚硝酸盐含量未见报道。本次研究发现,清水洗后的香椿,亚硝酸盐平均含量为34.1mg/kg;沸水烫后平均含量4．4mg/kg。用未经处理的香椿炒蛋。亚硝酸盐平均含量83．3mg/kg,经沸水烫后,平均含量为1.5 mg/kg。采用15%和30%浓度的盐水腌制,不能降低亚硝酸盐含量。沸水烫后的食用香椿可降低亚硝酸盐含量,减少亚硝胺的形成和诱发肿瘤的机会。     

温度和盐胁迫对油葵种子萌发及幼苗生长的影响

通过测定不同温度和盐胁迫浓度对油葵种子发芽势、发芽率和幼苗生理生化特性指标的影响,发现相同温度条件下,随着盐浓度的升高,油葵种子的发芽势、发芽率呈降低趋势,发芽时间延迟,胚根的生长受到抑制,胚根长、子叶鲜重均呈现下降的趋势;油葵幼苗的叶片和根系的电解质相对外渗率,SOD、POD活性均呈现先升后降的趋势。相同浓度盐胁迫下,油葵种子的发芽势和发芽率随温度的升高而升高,表现出喜温的特性,说明油葵种子在萌发阶段,适宜的高温条件有利于其种子发芽,幼苗对盐胁迫也有较强的适应能力。     

不同种源香椿芽硝酸盐、亚硝酸盐及VC含量变化的研究

对南京、四川、湖南、湖北、河南、陕西六个种源香椿芽硝酸盐、亚硝酸盐、VC的含量进行了比较研究。结果表明:同一时期不同种源香椿芽硝酸盐、亚硝酸盐及VC含量差异极显著,通过对不同时期不同种源香椿芽菜各成分的综合分析认为,湖南种源香椿的硝酸盐、亚硝酸盐含量较低,VC含量相对较高,为品质上乘的理想食用香椿种源。其它种源的香椿芽在4月9日之前,其硝酸盐、亚硝酸盐含量均未超出食用标准,且VC含量适中,可以放心食用。     

红油香椿嫩芽不同生长期和空间部位挥发性成分分析

以红油香椿幼嫩组织为研究对象,利用顶空固相微萃取及气相色谱-质谱联用技术分别对不同生长期、空间部位各香气成分种类和相对含量进行测定。结果表明：香椿生长期Ⅰ共检测到挥发性化合物成分35 种、生长期Ⅱ17 种、生长期Ⅲ 22 种、生长期Ⅳ15 种、生长期Ⅴ12 种、生长期Ⅵ16 种;随着香椿嫩芽的不断生长,羰基类、含硫类、醇类整体均呈先上升后下降的趋势,烯类整体呈先下降后上升趋势,烃类、其他类均逐渐下降。红油香椿嫩芽上部共检测出挥发性香气成分26 种、中部19 种、下部12 种,其中含硫类化合物相对含量分别达72.15%、88.33%和88.59%,构成香椿的主要香气成分。根据不同空间部位香椿特征香气成分2-巯基-3,4-二甲基-2,3-二氢噻吩相对含量推测,中部为香椿香气释放的关键部位。     

降低腌制香椿中亚硝酸盐含量的研究

研究了食盐,维生素C,葡萄糖,茶叶对香椿腌制过程中亚硝酸盐形成的影响.结果表明:加入香椿质量10%~20%食盐的香椿腌制品在第3 d和第25 d时出现亚硝酸盐高峰;添加质量分数0.03%的维生素C和0.2%的葡萄糖,对腌制香椿半成品中亚硝酸盐形成有明显的抑制作用;添加茶叶对香椿腌制后期的亚硝酸盐含量降低有一定作用.     

泡制香椿亚硝酸盐变化规律及其降低措施研究

香椿是人们喜欢食用的木本蔬菜,但香椿中含有较多的亚硝酸盐,亚硝酸盐对人体健康危害较大。试验以香椿为研究材料,比较了传统香椿的泡制方法与分别接种植物乳杆菌、反硝化细菌,添加抗坏血酸、葡萄糖等方法对泡制香椿中亚硝酸盐变化规律的影响,最终得出降低泡制香椿中亚硝酸盐含量的最优方案:食盐浓度为6%,接种植物乳杆菌,同时添加0.03%抗坏血酸、0.2%葡萄糖对降低泡制香椿中亚硝酸盐含量的效果最佳。     

不同采摘期及不同解冻方式对香椿香气含量的影响

为探究不同采摘期及不同解冻方式对香椿香气含量的影响,本试验对不同采摘期的香椿,经顶空固相微萃取提取香椿的挥发性组分后,用气相色谱的FPD检测器分析测定;同时对速冻香椿经3种解冻方式解冻后香椿香气的相对含量进行测定。结果表明,对不同采摘期而言,香椿特征香气随采摘期呈现先增后减的趋势,并且采摘于5月下旬的香椿香气最浓郁;对不同解冻方式而言,特征香气物质在常温解冻方式下达到最大值,且冻藏处理及解冻对物质A的影响较大。     

接种发酵和自然发酵酸菜的亚硝酸盐含量对比分析

目的:对比乳酸菌接种发酵法和自然发酵法生产酸菜中的亚硝酸盐变化情况,考察不同发酵方式对酸菜中亚硝酸盐含量的影响.方法:采用离子色谱法测定酸菜中的亚硝酸盐含量,对发酵过程中不同时间采集的样品进行分析,动态监测2种发酵方式中亚硝酸盐的产生和变化情况.结果:酸菜发酵过程中亚硝酸盐呈现先升后降的趋势,乳酸菌接种发酵法生产的酸菜在发酵过程中亚硝酸盐一直处于较低水平,在5d出现峰值,发酵至15d亚硝酸盐几乎消失.而自然发酵法生产的酸菜发酵初期亚硝酸盐含量较高,峰值出现在7d,含量为20.84mg/kg,超过国家标准限度值,为达到绿色、安全和健康饮食的目的,最好将发酵周期控制在30d以上.结论:同样的发酵条件下,乳酸菌接种发酵法生产酸菜的生产周期更短,安全性优于自然发酵法的.     

不同利用方式对几种根茎类蔬菜亚硝酸盐含量的影响

以山药、胡萝卜、莲藕为实验材料,研究不同贮藏条件、烹饪方法和熟菜保存方式下3种根茎类蔬菜中亚硝酸盐含量的变化。结果表明：无论常温还是低温贮藏,贮藏7d内,3种根茎类蔬菜的亚硝酸盐含量均呈现先增加后降低的趋势,虽然常温贮藏的亚硝酸盐含量高于低温贮藏,但两者均小于4mg/kg。不同烹饪加工可显著降低3种蔬菜的亚硝酸盐含量,煮制、炒制、烤制加工方式的亚硝酸盐含量降幅分别为70%～83%、66%～80%和33%～55%,其中胡萝卜的亚硝酸含量降幅最大,莲藕的最小。低温和常温保存的熟菜,菜体中亚硝酸盐含量随时间延长而增加,保存到48h时,3种菜体的亚硝酸盐含量均小于4mg/kg,且低温远低于常温(前者最大为1.03mg/kg,后者最大为1.98mg/kg),参照食用的亚硝酸盐标准,低温(4℃)和常温(20℃)保存的熟制根茎类蔬菜食用安全期均达48h,且煮制和炒制加工的熟菜优于烤制。     

不同贮藏蔬菜中亚硝酸盐变化的研究

本研究以大白菜、甘蓝、白萝卜为试验材料,研究了室温、低温、腌制三种贮藏蔬菜中亚硝酸盐含量的变化及其形成的机理。结果表明:室温、腌制两种贮藏方法的初期都出现“亚硝峰”。形成“亚硝峰”的原因依贮藏方法而异,室温贮藏蔬菜中“亚硝峰”的形成是由于采摘后菜体内硝酸还原酶的活性增强导致蔬菜内硝酸盐还原成亚硝酸盐;腌制贮藏蔬菜中“亚硝峰”的形成是由于发酵过程中杂菌所致。腌制菜中“亚硝峰”的峰值大大高于室温贮藏,并超过FAO/WUO规定的ADI值,腌制后期亚硝酸盐含量在安全食用范围。室温、低温贮藏蔬菜中亚硝酸盐含量的最高值小于ADI值,可以放心食用。     

大麦苗富锗的研究

目的:探讨大麦苗不同富集锗的方法以及不同浓度的锗对大麦苗的生长及富锗量的影响,为开发富锗大麦苗保健品以及探索一条通过大麦苗的生物转化作用将环境中的有毒的无机锗转化为无毒的有机锗为人类服务同时又净化保护了环境的新途径。方法:水培法栽培大麦苗;浸麦富锗法,出苗后富锗法以及全程富锗法;原子分光光谱法测定富锗麦苗中锗的含量。结果:浸麦富锗法中锗浓度低于80mg/L组和出苗后富锗法中锗浓度为40mg/L组的麦苗生长曲线均高于空白对照组,且无麦苗尖发枯发黄现象。全程富锗法,各富锗组麦苗的出芽率、麦苗出率、生长曲线大部分低于空白对照组,且麦苗尖发枯发黄。结论:出苗后富锗法,当锗浓度为40mg/L时,大麦出芽率、麦苗出率、生长曲线均高于空白对照组,麦苗尖无发枯发黄,锗含量高是空白对照组的9.7倍,此为本实验中最佳富锗方法与最佳富锗浓度。     

Protease inhibitors in germinating echinocloa (Echinocloa fruneutacea) seeds: Changes in protease inhibitory activities during germination

Antitryptic activity in echinocloa seedlings disappeared completely by the seventh day during germination, whereas antichymotryptic activity remained at a level comparable with that of the dormant seeds. Purified trypsin/chymotrypsin inhibitor from dormant echinocloa seeds was used as a substrate to study the nature of proteases arising during germination. A carboxyl protease localized in the root portion of the seedlings was responsible for the inactivation of the seed inhibitor with reference to the loss of antitryptic activity, and a thiol protease diminished its antichymotryptic activity in vitro. The shoot portion of the seedlings contained both antichymotryptic activity and antitryptic activity. The root extract preferentially destroyed the antitryptic activity of the shoot extract. The data suggest that the trypsin/chymotrypsin inhibitor of echinocloa seed is inactivated and mobilized during plant growth and that a new inhibitor appears in the shoot portion of the plant during growth.     

THE STIMULATION OF PHENOLICS AND ANTIOXIDANT ACTIVITY IN PEA (PISUM SATIVUM) ELICITED BY GENETICALLY TRANSFORMED ANISE ROOT EXTRACT

A series of dark germination experiments demonstrate the potential of an Agrobacterium rhizogenes‐transformed, high cytokinin root extract of anise (Pimpinella anisum), to stimulate phytophenolic and enhance antioxidant activity in pea (Pisum sativum) seedlings. Average shoot weight increased 40–60% after imbibing seeds for 24 h in a 1.5 to 2.0% extract of the anise root clone AR‐10. Phenolic concentration was positively correlated with shoot weight, suggesting that the total phenolic content was related to seedling vigor. Antioxidant protection factor in pea shoots was also stimulated by AR‐10 extracts. Free proline concentrations were 2–3 times higher in shoots collected from AR‐10 treated peas versus controls. However, proline content also increased as shoot weight declined after being subjected to an overdose of AR‐10 extract in 25% ethanol. G6PDH specific activity, the first committed step of the pentose phosphate pathway, was negatively associated with shoot growth and proline concentrations.     

烤烟不同育苗方式的对比试验

为寻求适合贵州烟区烤烟生产实际的育苗新技术,对漂浮育苗、托盘水床育苗和常规育苗3种育苗方式进行了对比试验。结果表明:托盘水床育苗和常规育苗全天苗床温度变化相对较慢,而漂浮育苗系统升、降温迅速。托盘水床育苗的幼苗生长迅速,烟苗株高、叶数合理,茎干粗壮,叶面积较大,烟株根系发达,干物质积累量大;漂浮育苗的烟苗前期生长缓慢而后期生长迅速,成苗素质明显低于托盘水床育苗。托盘水床培育的烟苗光合速率、根系吸收面积明显占优势,根系活力与常规育苗基本一致,但明显高于漂浮育苗。因此,托盘水床育苗技术适宜于贵州烟区应用。     

Preference and juiciness of Iberian dry-cured loin as affected by intramuscular fat content, crossbreeding and rearing system

Preference ranking tests for juiciness and overall liking of dry cured loins from Iberian pigs with different genetic backgrounds (pure Iberian or crossbred Iberian×Duroc pigs), reared under different productive systems (outdoors on acorns and grass or indoors with mixed diets) and with different intramuscular fat (IMF) content, were conducted. IMF showed a positive influence on preference for juiciness and liking in subjects over 25 years of age, while younger consumers showed a similar trend for juiciness but not for preference. Loins from pure Iberian pigs showed significantly better ranking for juiciness and overall liking than those from crossbred pigs, even when the IMF content was similar. Dry cured loins from pigs reared outdoors and fed on acorns and pasture were ranked significantly better than those from animals fed indoors on concentrates, even though the mixed diets used were enriched in monounsaturated fatty acids and vitamin E in order to obtain meat with similar features to that of pigs reared outdoors, and despite very similar IMF contents. In conclusion, dry cured loins with high IMF content, from pure Iberian pigs and reared outdoors on acorns and grass attain the highest consumer preference.     

Effects of waterlogging at different stages of development on the growth and yield of peas (Pisum sativum L.)

The effects of waterlogging, for up to 8 days at different stages of development, on the growth and yield of peas have been examined. The peas were grown outdoors subject to field conditions in lysimeters containing monolith sandy loam or clay soils, in facilities where drainage and rainfall could be controlled. The experiments, made during 2 years, involved waterlogging treatments likely to be the most extreme occurring in the pea-growing areas of the UK. During each waterlogging treatment the oxygen concentration at 20 cm depth in the soil declined to less than 2% within 2 days. On average, when the soil was waterlogged to the surface for 5 days at the 1–2, 3–4 and 6–7 leaf stages (the latter being just before flowering), the losses of yield of seeds (peas) at the freezing stage were 6, 15 and 42%, respectively. The severity of the effect depended on the duration of the treatment and the height of the water-table; at the 6–7 leaf stage either 2 days waterlogging to the surface or 5 days with the water-table at 50 cm below the soil surface had little effect on seed yield. Waterlogging restricted leaf expansion and internode extension. After waterlogging at the pre-flowering stage, leaves usually senesced prematurely and the shoot apex became prematurely quiescent. In all experiments the yield of haulm was more affected by waterlogging than were the yields of pods and seeds. The losses in yield were mainly a consequence of fewer pods per plant. Waterlogging before flowering for 5 days depressed the concentrations of nitrogen, phosphorus and potassium in the haulm grown on both soils and of nitrogen in the seeds (peas) of plants in 1 year on the clay. Other treatments had little effect on nutrient concentration. After waterlogging to the surface for 5 days before flowering the uptake of water by roots was restricted, but other treatments had only a small effect, being least in the early treatments.     

Comparison of post‐germination mobilization of cell wall polysaccharides and non‐cell wall carbohydrates in soybean (Glycine max L.) cotyledons

BACKGROUND: In previous research, we demonstrated that cell wall polysaccharide (CWP) levels of soybean (Glycine max L.) cotyledons are negatively correlated with the sum of seed oil and protein content. Although the results suggest that reducing cotyledon CWP levels would be desirable, it is not known whether CWP are mobilized during early seedling growth and, if so, to what extent mobilization contributes to seed reserves. RESULTS: Ungerminated (dry) seeds contained equivalent amounts [approximately 20 mg (cotyledon pair)^?1] of non‐cell wall carbohydrates (NCWC) and CWP. Galactose and arabinose accounted for 47% of total CWP in cotyledons of dry seeds. Measured 14 days after planting (DAP), the levels of NCWC and CWP were reduced 98% and 34%, respectively, in cotyledons of seedlings grown under a 16‐h photoperiod. Measured 14 DAP, greater than 85% of cotyledon cell wall galactose plus arabinose was mobilized. The transformation of the cotyledon to a photosynthetic organ was associated with restructuring of the cell wall involving increases in uronic acids, glucose and rhamnose. CONCLUSION: CWP of soybean cotyledons are modified during early seedling growth due to mobilization and cell wall restructuring triggered by light. The amount of carbon mobilized makes only a small contribution to total cotyledon reserves. Published 2009 by John Wiley & Sons, Ltd.