2,4-D、Dicamba和KT对小麦成熟胚离体培养的影响

为了建立优良小麦品种遗传转化的高效组织培养体系,以扬麦158和郑麦9023成熟胚为外植体,探讨了Dicamba和2,4-D及KT对小麦成熟胚愈伤组织诱导和再生的影响。结果表明,Dicamba和2,4-D的愈伤组织诱导率最低为88.7%,最高可达95.1%,处理间无显著差异。不同激素诱导的愈伤组织在添加KT的培养基上分化时,再生率存在显著差异。两种基因型小麦用Dicamba诱导的愈伤组织比2,4-D诱导的愈伤组织具有更高的再生率。在分化培养时,培养基中添加5mg·L-1 KT比添加3mg·L-1的分化效果更好,但不同浓度KT对愈伤组织分化的效果因诱导激素的配比和基因型而异。扬麦158的综合指标更优,平均再生率可达20.1%,比郑麦9023高6.6%;采用4mg·L-1 Dicamba进行愈伤组织诱导,配合5mg·L-1KT分化培养更有利于小麦成熟胚离体培养。     

节节麦幼胚再生体系的建立

为建立高效的节节麦幼胚再生体系,以节节麦幼胚为外植体,通过正交设计,探索基本培养基、2,4-D、碳源、KT等因素对幼胚愈伤组织诱导、分化及植株再生效果的影响。结果表明,4种因素中,基本培养基对节节麦幼胚愈伤组织诱导的影响最显著(P0.05),2,4-D浓度对节节麦幼胚愈伤组织诱导也有显著影响(P0.05),添加3.0mg·L~(-1) 2,4-D的培养基诱导出的愈伤组织质量高,淡黄色,表面呈不规则颗粒状,质地致密,再生频率可以达到17.62%。KT浓度对节节麦愈伤分化影响最显著,基本培养基、2,4-D和碳源对节节麦幼胚愈伤分化均无显著影响。不同碳源对节节麦幼胚愈伤组织诱导和分化的影响均不显著,为节约成本可直接选用30g·L~(-1)蔗糖作为碳源。节节麦幼胚组织培养的最佳组合是:愈伤诱导培养基为MS培养基+3mg·L~(-1) 2,4-D+15g·L~(-1)蔗糖+15g·L~(-1)甘露醇,愈伤分化培养基为MS培养基+15g·L~(-1)蔗糖+15g·L~(~(-1))甘露醇+1.0mg·L~(-1) KT。     

切割处理和2,4-D对多棱裸大麦离体成熟胚出愈率的影响

为了筛选适宜成熟胚离体培养的多棱裸大麦材料,并建立其成熟胚愈伤组织的高效诱导培养技术体系,采用3次重复的L25(56)正交设计,探究成熟胚基因型、切割处理、外源生长素(2,4-D)、萘乙酸(NAA)、6-苄基嘌呤(6-BA)和矮壮素(CCC)对多棱裸大麦成熟胚出愈率的影响。结果表明,成熟胚基因型、不同浓度的2,4-D和切割处理均可影响多棱裸大麦成熟胚出愈率,且成熟胚基因型、2,4-D和切割处理间具有一定的组合效应;但不同浓度的NAA、6-BA和CCC对多棱裸大麦成熟胚出愈率没有显著影响。添加0.5~2.0mg·L-1的2,4-D可有效提高多棱裸大麦成熟胚出愈率,但诱导不同基因型的成熟胚愈伤组织所需2,4-D浓度不同。横向切割部分胚芽、横向切割部分胚根-胚芽和纵向切割部分胚均可提高多棱裸大麦成熟胚的出愈率,但横向切割部分胚根对成熟胚的出愈率没有明显影响。在25个处理中,处理Ⅱ、XX和XXV中成熟胚的出愈率分别达到了72.00%±1.91%、70.67%±2.66%、70.00%±1.25%,3个处理的大麦品种ZJ49、D4和ZJ46可用作多棱裸大麦成熟胚培养的候选材料。在25℃、光照16h、光强1 200lx条件下,以添加40g·L-1蔗糖和0.5mg·L-12,4-D的MS培养基培养纵向部分切割的ZJ49成熟胚、添加40g·L-1蔗糖和2.00mg·L-12,4-D的MS培养基培养横切部分胚芽的D4成熟胚或横切部分胚根-胚芽的ZJ46成熟胚,可高效诱导成熟胚愈伤组织。     

玉米幼胚培养及植株再生的研究

以不同玉米自交系幼胚为外植体,研究不同2,4-D浓度对愈伤组织诱导、6-BA浓度对愈伤组织分化和6-BA与NAA配合使用对试管苗生根的影响。结果表明:不同2,4-D浓度对愈伤组织诱导率影响差异不明显,但对胚性率诱导有明显影响,其诱导最佳培养基为MS+2,4-D 2 mg/L+水解酪蛋白500 mg/L+脯氨酸500 mg/L;愈伤组织分化的最佳培养基是MS+6-BA0.5 mg/L+水解酪蛋白500 mg/L+谷氨酰胺200 mg/L+PP₃₃₃ 2 mg/L;试管苗生根的最佳培养基是1/2 MS+6-BA0.5 mg/L+NAA2.0 mg/L+PP₃₃₃ 2.0 mg/L+活性炭0.2%。     

玉米成熟胚离体培养体系的建立

以玉米品种豫玉32和安玉12的成熟胚为外植体,利用正交实验研究蔗糖、2,4-D、AgNO3这3个因素及组合对玉米成熟胚胚性愈伤组织诱导的影响。结果表明,对安玉12诱导胚性愈伤组织的最佳培养基是MS+20g/L蔗糖+2.0 mg/L2,4-D+5.0 mg/LAgNO3,豫玉32诱导胚性愈伤组织的最佳培养基是MS+20 g/L蔗糖+4.0 mg/L2,4-D+10.0 mg/L AgNO3。     

水稻成熟胚盾片诱导愈伤组织再生体系的建立

采用水稻成熟胚盾片诱导愈伤组织作为分化再生的外植体，通过优化激素组合和调节培养基渗透压，建立了适合水稻遗传转化的高效再生体系，将水稻成熟胚诱导愈伤组织分化再生的过程划分为3个不同时期，即成熟胚盾片愈伤组织诱导，胚性细胞诱导保持，胚性愈伤组织分化再生，以CultureI(LS 2,4-D2.0mg/L)诱导成熟胚盾片愈伤组织，愈伤组织剥离后接种于Culture II-3(LS 2,4-D 2.5mg/L 山梨醇3g/L)上诱导胚性愈伤组织，继代后接种于Culture Ⅲ-2(MS NAA 0.5mg/L 6-BA 1.0mg/L Kinetin 2.0mg/L 山梨醇8g／L）上分化成苗，培养结果表明，该再生体系所获得的胚性愈伤组织分化再生率均在60％－80％之间，利用本研究建立的高效再生体系建立水稻外源基因遗传转化系统，使转化过程中所得转化愈伤组织高效再生成苗，从而顺利获得转化植株，可以提高水稻外源基因转化的效率，为水稻品种的定向遗传改良提供优良的遗传转化技术体系。     

外源物质对小麦幼胚胚性愈伤组织草酸盐氧化酶活性的影响

为了提高小麦幼胚体细胞再生频率,以河南省大面积推广的豫麦49、豫麦18和兰考906为材料,研究了不同浓度外源物质(2,4-D、ABA和AgNO3)对不同基因型小麦幼胚胚性愈伤组织草酸盐氧化酶活性的影响.结果表明,基因型问、不同外源物质浓度间小麦幼胚胚性愈伤组织草酸盐氧化酶活性差异均达到0.01显著水平.基因型间草酸盐氧化酶活性以豫麦18最高、兰考906最低;不同外源物质浓度间草酸盐氧化酶活性以MS培养基上附加2.O～3.0 mg/L 2,4-D、2.0 mg/L 2,4-D+0.1 mg/L ABA和2.0 mg/L 2,4-D+0.1 mg/L ABA+2.5～5.0mg/L AgNO3处理较高.不同外源物质条件下小麦幼胚胚性愈伤组织诱导率与草酸盐氧化酶活性存在极显著相关.     

离子注入后双胚苗突变水稻的无性系诱导

以离子注入后同源四倍体双胚苗突变水稻及其衍生后代为研究材料,利用无性系诱导技术对愈伤组织的脱分化和再分化特性进行了初步研究。研究结果表明,同源四倍体水稻与相应的二倍体水稻在无性系诱导中存在着明显的差异;在试验中将2,4-D浓度由2.0 mg/l提高到2.5 mg/l则可以获得比较高的诱导率;半胚乳处理不但能提高愈伤组织的诱导率,也能提高愈伤组织的质量,干燥处理能提高愈伤组织的分化率。     

玉米自交系郑58和丹340幼胚再生体系的建立

研究选取9个优良玉米品种的自交系,以幼胚为外植体,以N6、MS培养基为基本培养基,诱导愈伤组织,探讨基因型、培养基类型、外植体大小、激素浓度等因素对愈伤组织诱导率的影响,分析不同基因型愈伤组织生长状态的差异,对诱导成功的愈伤组织进行分化和再生。研究结果表明,基因型对愈伤组织诱导率起决定作用,且基因型和培养基之间存在相互作用;外植体大小在1.5～2.0 mm时的幼胚较适合诱导胚性愈伤组织;2,4-D对玉米幼胚愈伤组织的诱导形成起关键作用,浓度在2.0～2.5 mg/L时大多能诱导出胚性愈伤组织。     

铁兰体细胞胚的诱导及植株再生

以铁兰无菌苗为外植体,研究不同激素配比对铁兰胚性愈伤组织诱导及体细胞胚形成的影响,并对体细胞胚的发生过程进行形态学观察.结果表明:2,4-D对铁兰胚性愈伤组织的诱导具有重要作用,诱导铁兰胚性愈伤组织的最适2,4-D浓度为2.0 mg/L;胚性愈伤组织在含ABA的培养基上可分化形成体细胞胚.形态及解剖学观察表明,愈伤组织既可以产生于外植体的外层细胞,又可产生于外植体的深层细胞.体细胞胚的形态发生经历了与合子胚形态发生相似的阶段,即经过球形胚、子叶形胚等.胚经过萌发、芽的伸长和生根后形成再生植株.     

Fungitoxicity and synergism of mixtures of fluopicolide and pyraclostrobin against Phytophthora infestans

Fluopicolide and pyraclostrobin were new systemic fungicides with highly inhibitory activity on a broad spectrum of oomycetes, but so far the fungitoxicity of their mixtures on the different developmental stages of Phytophthora infestans and whether synergism exists have not been investigated. The joint-toxicity of the mixtures of fluopicolide with pyraclostrobin was determined against the different developmental stages (mycelial growth, zoospore release, cystospore germination and sporangial germination) of P. infestans and late blight on the leaf discs and the potted plants of potato, and whether the synergistic interaction exists in the mixtures of the two fungicides were evaluated in vitro and in vivo based on the synergistic ratios calculated with the Wadley formulas. The protective activity and curative activity against P. infestans and the efficacy duration in controlling potato late blight of the synergistic mixtures of the two fungicides were examined in this study. The results showed that mixtures of fluopicolide (F) and pyraclostrobin (P) at the ratios of 10:1 and 1:4 (F:P) exhibited synergistic interactions and had excellent inhibitory activity against almost all developmental stages of P. infestans. Synergistic interactions of the mixtures at the ratios of 1:4 and 10:1 (F:P) against the mycelial growth of metalaxyl-resistant isolates were more obvious than against the mycelial growth of metalaxyl-sensitive isolates. Synergistic interactions of the mixtures at the ratio of 1:4 (F:P) against the mycelial growth of the most of the tested isolates were more obvious than those of the mixtures at the ratio of 10:1 (F:P). The highest activity of the mixtures was observed against zoospore release at the ratio of 1:4 (F:P) with EC₅₀ value of 0.0044 μg ml⁻¹. The strongest synergistic interaction of the mixtures was observed against zoospore release at the ratio of 10:1 (F:P) with the synergistic ratio of 5.27. The mixtures of fluopicolide and pyraclostrobin at the ratios of 1:4 and 10:1 (F:P) showed synergistic interactions against P. infestans on the leaf discs and intact plants of potato. The EC₅₀ values for protective activity and curative activity of the mixture at the ratio of 10:1 (F:P) were 0.63 μg ml⁻¹ and 0.87 μg ml⁻¹, and EC₅₀ values of protective activity and curative activity of the mixture at the ratio of 1:4 (F:P) were 0.27 μg ml⁻¹ and 0.44 μg ml⁻¹, respectively. At 14 days after spraying of fungicide solutions, the disease control efficacy of the mixtures at the ratios of 10:1 and 1:4 (F:P) was still over 80% at the dosages of 50 μg ml⁻¹ and 100 μg ml⁻¹, and the disease control efficacy of the two mixtures remained at about 97% at the dosages of 200 μg ml⁻¹, indicating long-lasting effective control efficacy of the two fungicides against potato late blight.     

305份国内外小麦种质条锈病与白粉病抗性鉴定与评价

为获得抗病小麦种质以促进其在育种上的应用,利用与抗条锈病基因和抗白粉病基因紧密连锁或共分离的分子标记对国内外的305份小麦种质进行检测。结果显示,携带 Yr10、 Yr15、 Yr18、 Yr26、 Yr46、 Pm8、 Pm21和 Pm34基因的材料分别为5、10、23、0、4、100、1、95份,占比依次为1.63%、3.28%、7.54%、0、1.31%、32.79%、0.33%、31.15%。携带上述抗性基因且表现出中抗水平以上的材料分别依次有2、3、7、0、3、59、1、62个,还有部分表现抗病的种质未检测到以上8个基因,其抗性可能由其他基因控制。本研究中没有一个种质材料同时携带两个多效抗病基因 Yr18和 Yr46,但 Yr18和 Yr46分别通过与 Yr10、 Pm8和 Pm34等抗病基因的组合,极大提高了品种的综合抗病能力,如CA0548( Yr18+ Yr10)、川麦42( Yr46+ Pm34)、Fr03717( Yr18+ Pm34)、鄂恩5号( Yr46+ Pm8),以上材料对条锈病和白粉病均具备中抗以上的抗性。因此,以后要充分发挥多效抗性基因的优势并培育兼抗性小麦品种。     

云南咖啡主要病虫害及防治调查研究

对云南保山、德宏、普洱等地咖啡病虫害开展调查研究,结果表明：咖啡锈病(Hemileia vastatrix Berk et Br.)、炭疽病(Colletotrichum coffeanum Noack)、褐斑病(Cercospora coffeicola Berk. et Cooke)、幼苗立枯病(Rhizoctonia solani Kuhn.)、旋皮天牛(Acalolepta cervina Hope)、灭字虎天牛(Xylo     

Characterisation of the phospholipid fraction of hulled and naked tetraploid and hexaploid wheats

Phospholipid (PL) profile was determined on lipids extracted from the whole grains of 10 genotypes of tetraploid wheats (Triticum dicoccon Schrank and Triticum durum Desf.) and 10 genotypes of hexaploid wheats (Triticum spelta L. and Triticum aestivum L.) by a liquid chromatography system coupled on-line with an evaporative light scattering detector (HPLC-ELSD). Phosphatidylethanolamine, phosphatidylinositol and phosphatidylcholine were the major PL determined, accounting for more than 70% of total PL. PL represented about 10% of total lipids and were detected in naked wheats at levels of 10.1 and 10.4 g/100 g of lipids (T. durum and T. aestivum, respectively) whereas in the corresponding ancestors T. dicoccon and T. spelta PL amounts were 8.4 and 9.1 g/100 g of lipids, respectively. PL amount in naked wheats was about 17% higher than that determined on average in hulled wheats: 10.2 ± 2.8 vs. 8.7 ± 2.2 g/100 g of lipids, respectively. A hyphenated system HPLC-ELSC was revealed as a useful and more informative tool to identify different PL classes with a minimal experimental workout in comparison to the organic phosphorus assay. The identification of PL molecular species was performed by HPLC, employing as detector a mass spectrometer working in negative ASI-ES mode.     

Occurrence and characterization of fungi and oomycetes transmitted via potting mixtures and organic manures

A study was conducted to investigate the most common fungal and oomycete pathogens introduced into farms in Oman via potting mixtures and organic manures. A total of 37 commercial types of potting mixtures (2 local and 35 imported from overseas), 4 commercial types of organic manures and 11 non-commercial types of organic manures were included in the study. Identification of the isolated species was based on morphological characteristics, except for the most common species which were further identified using sequences of the internal transcribed spacer region of the ribosomal DNA (ITS rDNA). Fusarium spp. (14%), Pythium aphanidermatum (3%), Alternaria spp. (5%), Helminthosporium spp. (5%) and Cladosporium spp. (3%) were recovered at different frequencies from samples of potting mixtures. Fusarium solani (40%) and Fusarium equiseti (47%) were recovered at high frequencies from samples of organic manures. Isolations from organic manures also yielded Pythium periplocum (7%), Rhizoctonia solani (7%), Fusarium lichenicola (7%), Helminthosporium spp. (27%) and Alternaria spp. (27%). Trichoderma spp., Penicillium spp., Aspergillus spp. and Rhizopus spp. were found to be common in samples of potting mixtures and organic manures. Investigating sensitivity to hymexazol among 9 isolates of F. equiseti and 13 isolates of F. solani revealed variations among different isolates. The EC₅₀ values ranged from 1 to over 1200 (avg. 192 μg ml⁻¹) for F. equiseti isolates and from 135 to 789 (avg. 324 μg ml⁻¹) for F. solani isolates, indicating presence of resistance to this important fungicide among some Fusarium isolates. This appears to be the first report of contamination with R. solani, P. periplocum, F. solani, F. equiseti and F. lichenicola of organic manures. This study appears to report for the first time F. lichenicola in Oman and appears to be the first report of occurrence of resistance to hymexazol among F. equiseti and F. solani isolates.     

Investigation of Indolglyoxamide and Indolacetamide Analogues of Polyamines as Antimalarial and Antitrypanosomal Agents

Pure compound screening has previously identified the indolglyoxylamidospermidine ascidian metabolites didemnidine A and B (2 and 3) to be weak growth inhibitors of Trypanosoma brucei rhodesiense (IC₅₀ 59 and 44 μM, respectively) and Plasmodium falciparum (K1 dual drug resistant strain) (IC₅₀ 41 and 15 μM, respectively), but lacking in selectivity (L6 rat myoblast, IC₅₀ 24 μM and 25 μM, respectively). To expand the structure–activity relationship of this compound class towards both parasites, we have prepared and biologically tested a library of analogues that includes indoleglyoxyl and indoleacetic “capping acids”, and polyamines including spermine (PA3-4-3) and extended analogues PA3-8-3 and PA3-12-3. 7-Methoxy substituted indoleglyoxylamides were typically found to exhibit the most potent antimalarial activity (IC₅₀ 10–92 nM) but with varying degrees of selectivity versus the L6 rat myoblast cell line. A 6-methoxyindolglyoxylamide analogue was the most potent growth inhibitor of T. brucei (IC₅₀ 0.18 μM) identified in the study: it, however, also exhibited poor selectivity (L6 IC₅₀ 6.0 μM). There was no apparent correlation between antimalarial and anti-T. brucei activity in the series. In vivo evaluation of one analogue against Plasmodium berghei was undertaken, demonstrating a modest 20.9% reduction in parasitaemia.     

Volume change of bread and bread crumb during cooling,chilling and freezing,and the impact of baking

During baking, bread dough undergoes an expansion followed by a slight contraction at the end of baking. The contraction during baking has been evidenced by some authors. However, there is a limited amount of literature about the contraction of the crumb during the chilling phase and also during the freezing phase in the case of freezing. A study has been carried out to better understand the impact of the baking degree on the contraction of the crumb during chilling after baking and during freezing. The volume of the samples has been evaluated with a laser volumeter. Breads (70 g dough) were baked until reaching 75 °C, 85 °C, 95 °C, 98 °C and then 98 °C for 10 min. Results showed that a longer baking resulted in a lower contraction of the bread. The volume change was between 25% and 2.5% for baking at 75 °C—0 min dwell and 98 °C—10 min dwell, respectively. The contraction was compared to the contraction of degassed bread crumb samples, which was more important. SEM pictures showed that the degree of baking also corresponded to a very different structure of the crumb. For the longer baking, the starch granules were fully gelatinized and no ghosts of starch granules were visible. The magnitude of the contraction was thus associated with the degree of baking and with the degree of starch granule destructuration.     

播期和密氮组合对镇麦10号干物质积累及产量的调控效应

为确定江苏淮南麦区红皮强筋小麦高产栽培的适宜播期、种植密度和氮肥施用量,选用红皮强筋小麦新品种镇麦10号作为试验材料,在基施45%复合肥375 kg·hm^-2和尿素150 kg·hm^-2条件下,分析了播期和密氮组合对小麦群体干物质积累和产量的影响。结果表明,播期和密氮组合对镇麦10号产量及干物质积累量有极显著的影响。随着播期的延迟,镇麦10号产量先升后降,穗数和千粒重下降,穗粒数略有增加。11月5日播种较10月20日和11月20日播种分别增产2.26%和10.59%;种植密度对籽粒产量的影响因播期不同而有所差异;种植密度增加有利于提高有效穗数,但降低穗粒数和千粒重。10月20日播种时,提高种植密度不利于产量的增加,在基本苗225×10⁴ 株·hm^-2下平均产量最高,较基本苗300×10⁴ 和375×10⁴ 株·hm^-2分别增产3.52%和9.21%;11月5日和11月20日播种时,籽粒产量随着密度的提高而增加,以基本苗375×10⁴ 株·hm^-2的产量最高,较基本苗225×10⁴ 和300×104株·hm^-2分别增产6.32%、4.89%和4.58%、3.25%。增加追氮量有利于穗数、穗粒数和千粒重的增加,但过量追氮时,穗数、穗粒数和千粒重降低;追施纯氮120 kg·hm^-2可显著提高籽粒产量,追氮量过多过少均不利于产量的增加。早播、增加种植密度、增施氮肥均能促进镇麦10号干物质积累,但不利于产量的提高。在本试验条件下,镇麦10号高产最适播期为11月5日,最优密度为375×10⁴ 株·hm^-2,适宜追氮量为120 kg·hm^-2。     

FTIR and Solid StateC NMR Spectroscopy of Proteins of Wet Cooked and Popped Sorghum and Maize

Fourier transform infrared (FTIR) and solid state¹³C NMR spectroscopic methods were used to investigate changes in maize and sorghum proteins on wet cooking and popping. FTIR spectra indicated that wet cooking led to proteins in two normal sorghums, namely NK 283 (a red hybrid) and KAT 369 (a white variety), two sorghum mutants (P850029 and P851171) and a maize hybrid (PAN 6043) assuming more antiparallel intermolecular β-sheet character, possibly at the expense of some α-helical conformation. Solid state¹³C NMR, using the technique of Cross Polarisation Magic Angle Spinning showed shifts of the protein carbonyl carbon and α-carbon resonances upfield on wet cooking in all samples, also indicating a change in protein secondary structure from α-helical to β-sheet conformation. The extent of secondary structural change on wet cooking seemed to be greater in sorghum than in maize and may have a bearing on the inferior protein digestibility of wet cooked sorghum compared to maize. Popping produced the same secondary structural change as observed for wet cooking in both sorghum and maize. However, the extent of change on popping was less than on wet cooking in sorghum and maize.     

Characterization and degradation of lignin from steam explosion of pine and corn stalk of lignin: The role of superoxide ion and ozone

Steam explosion of corn stalk in the presence of 3% sulphuric acid at 200 °C for 5 min gave the highest recovery of lignin. Lignin has M_w = 2640 and M_z = 93,994. In the UV spectrum absorptions at λ = 231 and 280 nm were recorded. ¹H NMR spectrum of lignin showed signals attributable to cinnamaldehyde units, guaiacyl units, and syringyl units. Syringyl and guaiacyl units are in 1:1 ratio. ¹³C NMR spectrum showed signals for guaiacyl, syringyl, and p-hydroxyphenyl units. The spectrum showed a prevalence of guaiacyl units. The ¹³C NMR spectrum is in agreement with the presence of cinnamic units. The same characterization was performed on lignin from pine. The irradiation of lignin from pine from steam explosion process in the presence of oxygen, in conditions described for the formation of superoxide ion, for different irradiation time was followed isolating the lignin and determining the average molecular weight. The experiments showed that, until 8 h irradiation, M_n decreases, while M_w and M_z increases. After 8 h irradiation an inverse behaviour was observed, with an increase of M_n and a decrease of M_w and M_z. These results are in agreement with an initial polymerization process followed by a photoinduced degradation. Ozonization was carried out in acetonitrile–methanol solution. The reaction showed a zero-order kinetics. After 50 min the average molecular weight of lignin is the half. The reaction mixture was analyzed by using GC–MS. Oxalic acid was determined.