树仔菜植株多糖的提取与测定

采用超声萃取法、浸泡提取法和加热回流提取法进行树仔菜多糖的提取研究,并用苯酚-硫酸法进行多糖含量测定。结果表明,超声萃取法提取效率最高,树仔菜植株中多糖含量为0.36%。该分析方法简便、快速、准确、灵敏度好。     

Effect of vegetable fibre on post prandial glycemia

Effects of feeding different levels of vegetable fibre to normal and non-insulin dependent diabetics were studied. Influences of a control diet (diet with no vegetable fibre) and a purified fibre diet (Isapgol) were compared to results achieved with different levels of several vegetables. A negative correlation between the level of fibre and blood glucose levels in terms of mean percent peak rise, AUC, and per cent glycemic response was shown. Bitter gourd was more effective than the leafy vegetables. Even though the trend in post prandial glucose levels was same for both normal and diabetic subjects, the metabolic response varied significantly between the two groups.     

Antioxidant activity and phenolic content of chestnut (Castanea sativa) shell and eucalyptus (Eucalyptus globulus) bark extracts

Chestnut (Castanea sativa) shell and eucalyptus (Eucalyptus globulus) bark, waste products of the food and wood industries, respectively, were analysed as potential sources of antioxidant compounds. The extraction yield, the antioxidant activity and total phenols content of the extracts were greater in chestnut shell than in eucalyptus bark for most of the extraction conditions essayed. Extraction of chestnut shell with a 2.5% Na₂SO₃ aqueous solution led to the highest extraction yield, 25.6%, total phenols, 13.4 g gallic acid equivalent/100 g oven-dried shell, and FRAP antioxidant activity, 80.7 mmol ascorbic acid equivalent/100 g oven-dried shell. Extraction with methanol:water (50:50, v/v) provided the best results for eucalyptus bark. The antioxidant activity and the total phenols content of the extracts had a positive linear correlation. FTIR spectroscopy confirmed the higher content of phenolic compounds in chestnut shell extracts compared to eucalyptus bark extracts. Chestnut shell extracts were characterized by the presence of high molecular weight species whereas lower molecular weight species were predominant in eucalyptus bark extracts.     

基因枪介导的转 TaGAPDH8基因小麦的获得与鉴定

甘油醛-3-磷酸脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,GAPDH)是参与糖酵解和糖异生途径的关键酶之一,在维持细胞能量供应和植物抗逆性方面具有重要作用。本研究以耐旱型小麦品种长武134及干旱敏感型小麦品种郑引1号为材料,利用基因枪法将 TaGAPDH8基因分别转化这两种小麦的幼胚愈伤组织,经潮霉素筛选和PCR鉴定,最终得到4个下调表达的长武134株系(CW134-3、CW134-6、CW134-12、CW134-13)和8个上调表达的郑引1号株系(ZY1-1、ZY1-3、ZY1-4、ZY1-9、ZY1-10、ZY1-14、ZY1-15、ZY1-17)。对生长于大田的T_2代转基因植株在乳熟期的生长状况进行了测定,获得了与对照相比有明显表型差异的植株。用实时荧光定量PCR(qRT-PCR)技术测定了T_3代小麦株系中 TaGAPDH8的表达量,结果表明,4个长武134株系中 TaGAPDH8基因的表达量分别为对照的0.53、0.75、0.21和0.78倍,而8个郑引1号株系中目的基因的表达量分别为对照的3.02、1.22、2.15、1.36、4.02、1.87、1.48和1.97倍。本研究获得了与对照存在明显表型差异的T_2代及稳定遗传目的基因的T_3代小麦株系,为后续的试验提供了研究材料和基础。     

小麦EPF/EPFL基因家族的全基因组鉴定及 TaEPF1-2B与气孔性状的关系分析

表皮模式因子EPF/EPFL基因家族编码一类植物中特有的分泌类蛋白,在植物生长发育特别是形态建成过程中发挥着重要作用。为挖掘和利用小麦EPF/EPFL家族基因,对小麦该家族基因进行了系统鉴定,并利用生物信息学技术对其基因结构、蛋白质结构域、系统进化及表达特性进行分析。结果表明,在小麦全基因组水平共鉴定到35个TaEPF/EPFL基因家族成员,含有1~4个外显子,分布在除1A、5B外的19条染色体上,全基因组复制事件是导致该基因家族扩张的主要原因。蛋白结构分析显示,其编码蛋白的C端包含6个相对保守的半胱氨酸残基,N端存在信号肽剪切位点,且亚细胞定位在胞外基质中,属于一类胞外分泌蛋白。系统进化分析发现,TaEPF/EPFL基因在单子叶和双子叶植物分化之前就已形成。表达模式分析发现,大多数TaEPF/EPFL基因在小麦幼嫩组织和穗部表达量较高,部分TaEPF/EPFL基因响应干旱、高温等非生物胁迫。进一步分析 TaEPF1-2B不同单倍型与气孔性状的相关性,发现TaEPF1-2B不同单倍型的气孔密度、气孔长度、气孔宽度和气孔面积均存在极显著差异,净光合速率存在显著差异,其中单倍型Hap A具有较低的气孔密度和较高的光合速率,是优势单倍型。本研究结果为进一步改良小麦的抗旱性和光合效率提供了候选基因。     

农杆菌介导的小麦成熟胚遗传转化影响因素分析

为解决农杆菌介导的小麦成熟胚遗传转化效率较低的难题,以春小麦Bobwhite成熟胚为外植体,分析植物激素、愈伤组织预培养时间、侵染时间和共培养阶段干燥处理对小麦成熟胚愈伤组织遗传转化的影响,并在遗传转化处理中辅以3个组织再生相关基因(TaSERK1、TaSERK2、TaNiR)的qRT-PCR分析。结果表明,愈伤组织预培养阶段添加适量的2,4-D和Picloram均可诱导成熟胚愈伤组织的形成,但是2mg·L~(-1)Picloram培养基中愈伤组织的胚萌发率为20.78%,远高于2,4-D诱导的胚萌发率(11.38%);共培养阶段对农杆菌侵染的愈伤组织进行干燥处理能适当提高愈伤组织的转化效率;qRT-PCR分析发现再生相关基因TaNiR相对表达量的增加能适当提高愈伤组织的转化率。     

白燕2号EMS突变体的形态鉴定与遗传变异分析

为促进燕麦的遗传改良,采用化学诱变剂甲基磺酸乙酯(Ethyl methane sulfonate,EMS)处理裸燕麦品种“白燕2号”种子,构建燕麦EMS突变体库,对获得的M²代突变体的形态特征进行调查鉴定,估计突变效果并采用内含子切结点引物和长随机引物的PCR技术分析M²代突变体间的遗传多态性。结果显示,所创制的燕麦突变体库的M²代个体间表现出了丰富的遗传变异,变异的总频率为 7.17%。采用15个内含子切接点引物和长随机引物对其中39个突变体株系进行PCR检测,共扩增出99条谱带,其中多态性条带65条,多态性条带比率为65.7％。突变体株系间的遗传相似系数为0.667～0.973,表现出丰富的遗传变异。表明构建的燕麦EMS突变体库具有丰富的突变类型,可用于燕麦重要性状突变体的筛选和候选基因的功能分析。     

玉米对小斑病T小种抗性的遗传模型分析

用广义遗传模型方法,研究了玉米对小斑病T小种的抗性遗传特性.结果表明:玉米对小斑病T小种的核抗性主要受加性和显性效应控制,以显性效应为主.3个病害指标之间有极显著的正相关,相关性主要归因于加性效应,病斑数和病级之间还有显著的显性遗传相关.另外,根据遗传效应预测值对供试亲本作了评价。     

小麦种子萌发基因TaJAZ1的克隆和功能研究

小麦品种铭贤169是我国黄淮麦区育种研究广泛应用的条锈病诱发材料,但其种子休眠时间过长,不仅影响播种后均匀发芽和生长发育,其收获掉落籽粒也容易导致秋季育种田的生物学混杂。本研究通过筛选其休眠种子与萌发种子的转录组学数据,克隆获得差异表达基因TaJAZ1,并对其生物信息学特性、亚细胞定位、表达模式进行分析,结合解析拟南芥jaz3（与TaJAZ1同源性最高）突变体、TaJAZ1过表达拟南芥和水稻的表型反应。结果表明,TaJAZ1基因编码区全长1 230 bp,可编码409个氨基酸,在不同物种间保守性较强,与野生二粒小麦JAZ1基因的亲缘关系最近;启动子区含有脱落酸响应元件ABRE 和茉莉酸甲酯响应元件CGTCA-motif和TGACG-motif;该基因定位于细胞核和细胞膜,TaJAZ1基因在种子发育中穗发芽时期表达量达到最高,进入成熟时期表达量显著降低;ABA能诱导TaJAZ1基因的表达,ABA处理下过表达拟南芥的萌发率比野生型和jaz3突变体高,ABA信号通路基因AtABI5的诱导量变低;TaJAZ1过表达水稻的萌发率高于受体水稻, ABA处理后,OsABI5的诱导量也降低。以上结果证明,TaJAZ1基因能促进种子萌发,进一步验证其在ABA信号通路中起负调控作用,为改良铭贤169等强休眠性小麦品种提供参考。     

Nutritive characterization of purslane accessions as influenced by planting date

The uniqueness of purslane (Portulaca spp.) asthe richest vegetable source of omega-3 (-3)fatty acids is well documented. However, purslane hasnot been domesticated or fully evaluated for itsnutritive value. The objective of this study was todetermine the influence of planting date on chemicalcomposition of purslane accessions. Eight accessionsfrom different geographical locations were planted 12days apart, and whole plants harvested at full bloom. Chemical analysis (DM basis) of leaves showedsignificant differences among varieties for all thecharacteristics measured. Accession by planting dateinteraction influenced (p < 0.05) levels of crudeprotein, total lipids, and carbohydrate contents. Wild Greek accession had the highest, while aBeltsville (Maryland) wild type had the lowest crudeprotein content (27.1 vs 20.5%) at the secondplanting date. Crude protein, lipid and ash levelswere most influenced (p < 0.05) by planting date. Total lipids varied from 4.0–5.8% and 3.7–5.1% forthe first and second planting dates, respectively. Selected fatty acid content indicated significantly(p < 0.05) higher levels of 18: 26, and18: 33 in the Dutch Garden accession comparedwith other varieties. The Egyptian wild accession hadthe lowest level of 18: 33. The ratio of 3 to 6 acids, which ranged from 5.5 to22.3 indicated a highnutritive value of purslane compared to other oilcrops such as soybeans and perrilla. The high levelsof protein in purslane compete with those of othercommercially important vegetable crops. The studyshows that, in spite of its genetic diversity, purslaneremains one of the most abundant terrestrial vegetablesources of Omega-3 fatty acids and other essentialnutrients potentially beneficial for humans as well asanimals.     

Protein Inhibitors ofAlpha-amylase in Mature and Germinating Grain of Rye (Secale cereale)

The activities of endogenous (R-type) and exogenous acting (D-type) protein inhibitors ofalpha-amylase and the activities ofalpha- and total amylase were determined in milling fractions of rye. High D-type amylase inhibitor activities were detected in the embryo (255 IU/g) and in the endosperm fraction (64·9 IU/g), low inhibitor activities were found in the aleurone layer fraction (25·9 IU/g). The highest R-typealpha-amylase inhibitor activity was found in the aleurone layer fraction (32·6 IU/g), and the lowest value in the epidermis containing fraction (5·0 IU/g). The D- and R-typealpha-amylase inhibitor activities varied with growing conditions. D-type amylase inhibitor activities were found to be high in those samples which grew under drought conditions and low in samples cultivated under wet and cool weather. Higher R-typealpha-amylase inhibitor activities were found in rye genotypes cultivated under wet conditions and lower values under dry weather. There were small variations inalpha-amylase inhibitor activities between sprout-stable and sprout-sensitive rye genotypes. The D- and R-typealpha-amylase inhibitor activities of all varieties were stable during 72 h of germination. Similar soil conditions will therefore lead to differentialalpha-amylase inhibitor activities depending on weather conditions during growth.     

利用SNP标记和宁7840×Clark重组自交系(RIL)群体检测小麦染色体偏分离区域

为给小麦偏分离规律研究及小麦农艺性状的QTL定位研究提供相关信息,以普通小麦(Triticum aestivum L.)宁7840和Clark杂交得到的F12重组自交系(RIL)为试验材料,利用筛选出的2 404个单核苷酸多态性SNP标记和291个SSR标记对该群体进行遗传分析。结果表明,共有494个标记位点表现偏分离,占总标记数的18.3%,其中有429个标记偏向父本Clark,占偏分离标记数的86.8%,65个标记偏向母本宁7840,占偏分离标记数的13.2%。大多数偏分离标记在连锁图谱上成簇分布,形成偏分离区域(Segregation distortion region,SDR),共检测到33个SDR,分别位于1A、1B、2A、2B、3A、4B、5A、6A、6B、7A、7B和7D染色体上,其中有6个SDR偏向母本宁7840,27个SDR偏向父本Clark。杂合致死基因Ne2、导致偏分离的QSd.ksu-7D、核质互作增强子基因scs所在染色体区间分别与SDR-2B.1、SDR-7D.1、SDR-1A.2存在部分重合,这3个SDR中可能存在上述基因或其同源基因,在合子体选择和配子体选择共同作用下造成偏分离,形成SDR。     

杂交小麦强优势组合抗白粉病基因的定向导入与改良研究初报

为创制杂交小麦白粉病抗性定向改良育种新体系,以白粉病抗源材料N95175、N9134为抗病种质,以强优势杂交小麦新品种"西杂一号"和"西杂五号"的亲本为受体,以陕西不同地区小麦白粉病流行混合菌种为菌源,对供试材料亲本、杂种F1代和回交后代材料进行了苗期和成株期抗性鉴定,并利用与抗白粉病基因Pm21共分离的SCAR标记、抗白粉病基因PmAS846紧密连锁的SSR标记作为抗病性定向选择分子标记进行了抗病性鉴定。结果表明,以N95175、N9134为亲本的杂种F1含有Pm21基因或PmAS846基因,苗期和成株期均表现为高抗,与抗病亲本的抗病性表现基本一致,符合杂种优势表现显性假说,其抗病性主要由显性单基因控制。研究同时表明,仅凭借表型鉴定结果盲目性较大,表型鉴定和分子标记鉴定相结合准确率较高。     

Effect of Untreated, Roasted and Germinated Black Gram (Phaseolus mungo) Flours on the Physico-chemical and Biscuit (Cookie) Making Characteristics of Soft Wheat Flour

Determination of the physico-chemical characteristics of composite soft wheat flours in which 5–25% (w/w) of the wheat flour was replaced with untreated, roasted and germinated black gram (Phaseolus mungo) flours (BGF) showed that when roasted BGF comprised 20% (w/w) of the blend, the increases in the ash and protein contents were 123% and 35%, respectively. The values for the gluten contents and the Zeleny and sodium dodecyl sulphate sedimentation test volumes for the composite flours indicated a weakening effect of BGF on the quality of soft wheat flour proteins, which could be beneficial for the preparation of biscuits (cookies). The alkaline water retention capacity values increased with the increasing addition of differently processed BGFs. Biscuit baking studies indicated that the diameter and spread ratio of biscuits were reduced, while the thickness increased, with increasing addition of all three BGFs, but the maximum reduction in diameter was observed with the addition of germinated BGF. The hardness value for biscuits increased with the addition of BGFs, but the effect was minimal with roasted BGF and maximal with germinated BGF. The surface grain score was reduced with increasing addition of BGF, but, in general, the roasted BGF showed the minimum adverse effect. From the overall biscuit making quality, addition of untreated BGF at the 15% level and of roasted and germinated BGFs at the 20% level were considered optimal for supplementing wheat flour.     

S组山羊草属Psy1基因片段的克隆与序列分析

类胡萝卜素含量是影响小麦面制品色泽的主要因素,而Psy1基因则是类胡萝卜素生物合成中的关键基因。为了了解小麦近缘种S组山羊草的Psy1基因多样性分布规律,以高大山羊草、双角山羊草及西尔斯山羊草为材料,应用同源基因克隆技术对其进行Psy1基因克隆。结果表明,利用分子标记YP7B-5检测获得的8个新Psy1-S1等位变异的部分序列覆盖了Psy1基因的第二外显子和第二内含子的全部以及第三外显子93.1%的区域。在与包括来自普通小麦的Psy1-B1d、栽培二粒小麦的Psy1-B1k以及拟斯卑尔脱山羊草的Psy1-S1a、Psy1-S1b、Psy1-S1c对应部分的序列综合分析发现一致性高达93.4%~98.5%,而且编码区序列差异均为同义突变,没有造成编码氨基酸的变化。而第二内含子序列则存在数个SNP及InDel,尤其是Psy1-S1h的161bp大片段插入和Psy1-S1i的177bp大片段缺失,导致与其他Psy1-B1/Psy1-S1等位变异产生较大的长度差异。分析表明,内含子的差异是造成Psy1基因多样性的主要原因。     

小麦重组自交系群体大粒品系籽粒灌浆特性研究

为了明确大粒小麦的灌浆特性,以豫农9901/周麦16重组自交系群体中籽粒大小基本一致而饱满度和粒重具有较大差异的11个半冬性品系为试验材料,以周麦18为对照,分析了籽粒灌浆特性及阶段性灌浆参数与粒重的关系.结果表明,籽粒灌浆呈“慢-快-慢”的变化规律,可以用logistic曲线方程拟合其增长趋势;粒重较高的品系W02、W03与对照周麦18具有相似的灌浆特性,其他品系的籽粒灌浆特性与对照周麦18有明显差异,表现在前期灌浆速率高于周麦18且增速较快,后期则明显低于周麦18且下降的幅度较大;在三个灌浆阶段参数中,缓增期灌浆速率、渐增期和快增期持续时间明显低于周麦18,而缓增期持续时间明显长于周麦18.通径分析表明,阶段灌装参数中对粒重直接作用最大的是快增期持续时间,其次是缓增期持续时间,但是缓增期持续时间对粒重的直接正向效应被其较大的负向间接效应所掩盖;快增期和缓增期灌浆速率对粒重的间接效应明显大于直接效应.     

Nutrient composition of the leaves and flowers ofColocasia esculenta and the fruits ofSolanum melongena

The nutrient composition, ofColocasia esculenta flowers (CF) and leaves (CL), and the green fruits ofSolanum melongena (SM) were carried out as a means to determine their nutritional potential. Results showed that these food materials had high moisture and fiber levels which ranged between 888 and 906 g·kg^–1; and 204 and 303 g·kg^–1 dry weight (dw) for moisture and fiber respectively. The calorific values were between 3889 and 4001 kcals·kg^–1 dw, while the total lipids ranged from 53 in CF to 71 g·kg^–1 dw in SM. The leaves ofColocasia esculenta had the highest crude protein value of 307 g·kg^–1 dw. The flowers had 149 g·kg^–1 dw while SM had 138 g·kg^–1 dw. The amino acid profile in the flowers and leaves ofColocasia esculenta in contrast to SM were balanced comparable to the reference FAO pattern. Ash values were high (ranging from 76 in SM to 98 g·kg^–1 in CL) with potassium being the principal element. Iron and Zinc levels were also high especially in CF (with 303 and 82 mg·kg^–1 dw respectively). These foods also contained moderate quantities of calcium, phosphorus and magnesium but were poor in manganese and copper.     

新疆伊犁地区小麦条锈菌群体遗传结构分析

新疆伊犁地区是小麦条锈病的常发区和重发区，其年平均发生面积超过100×10⁴ hm²以上。为明确新疆伊犁地区小麦条锈菌群体的遗传结构，2021年，从新疆伊犁地区的新源县、巩留县、察布查尔县和伊宁县共采集到320份小麦条锈菌标样，利用16对小麦条锈菌SSR引物进行了群体遗传研究。结果表明，新疆伊犁地区条锈菌群体遗传多样性水平较高，群体间存在一定的遗传分化。群体间遗传变异仅占总变异的12%，群体内遗传变异占88%，不同群体间存在频繁的菌源交流，其中察布查尔县与新源县群体菌源交流最为频繁（N_m=4.717）。     

Accumulation and distribution of free folic acid content in red beet (Beta vulgaris L.)

Among vegetable plants, red beet contains a relatively high level of the B vitamin folic acid. Although many leafy green vegetables contain high levels of folic acid, red beet is consumed primarily as a root vegetable. Folic acid levels have been quantified in various vegetable plants, but little information exists regarding the accumulation and distribution of this vitamin in plant tissues. The objective of this study was to characterize free folic acid content (FFAC) in shoot and root tissue during growth of two red beet inbreds. Experiments were conducted in a greenhouse during 1993, 1994 and 1995. Two inbreds, W384 and W357, were planted in randomized complete blocks and shoot and root tissues were separately harvested at 60, 80, and 100 days after planting (DAP). Significant differences between years, tissue portions, and among harvest dates were detected, however, similar patterns in FFAC accumulation and distribution were observed between inbreds and years. FFAC in shoot tissue was significantly greater than root tissue for both inbreds. Accumulation of FFAC was linear for both inbreds across harvest dates for root tissue but not for shoot tissue. FFAC accumulation in shoot tissue increased sharply from 60 to 80 DAP but decreased sharply from 80 to 100 DAP. These results demonstrate that FFAC accumulates differentially in root and shoot tissue in a red beet plant. Maximum folic acid levels in shoot tissue are achieved prior to those in root tissue.     

Protein extraction from Atriplex lampa leaves: Potential use as forage for animals used for human diets

The purpose of this study was to evaluate the effectof pH on the extraction of protein nitrogen from Atriplex lampa leaves (Moquin) Dietrich. Thechemical characterization of the dry matter indicated thefollowing (g/100 g): protein, 26.93; ash, 21.80; etherextract, 4.65; dry matter, 37.30; sodium, 6.05; and calcium, 0.41.Non-critical values were obtained for saponins andnitrates. The high concentration of oxalic acid (8.52 g/100 g),together with elevated salt content accountfor the low palatability of the studied species.In order to determine the parameters needed to improvethe extraction in protein nitrogen from leaves, freshmaterial was macerated with 2% sodium metasulfite,followed by pulping with a hand-driven grinder.Extractions were performed at different pH values(2–12) adjusting the value with 5N HCL or NaOH, withagitation followed by centrifugation and pressing.Supernatants were collected and kept. The lastextraction was performed with Tween 20 in order toobtain maximum nitrogen recovery from the residuecake. Highest extraction (41.23%) was obtained at pH10 with a 1:5 ratio (leaf : deionized water, w/v). Itis proposed that this regional natural resource may beused to elaborate a protein concentrate, which can bemade more palatable by decreasing potassium and sodiumsalt content with the use of membrane technology.