玉米杂交种郑单958及其双亲自交系耐盐碱性分析

以玉米杂交种郑单958及其双亲自交系为材料,在4个浓度水平的Na2CO3溶液(12.5、25、37.5、50 mmol/L)和4个浓度水平的NaCl溶液(50、100、150、200 mmol/L)胁迫下,利用沙培法进行种子萌发和幼苗胁迫试验,分别测定发芽率、相对电导率等生理指标及脯氨酸(Pro)含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量等生化指标,比较杂交种与双亲自交系之间的耐盐碱差异。结果表明：郑单958及双亲自交系耐盐碱筛选最宜浓度为25 mmol/L Na₂CO₃和100 mmol/L NaCl溶液,且Na₂CO₃对于质膜透性的伤害程度大于NaCl;玉米耐盐碱筛选适宜生化指标为SOD活性、MDA含量以及Pro含量,其中Pro含量是玉米耐盐碱筛选的重要指标,其含量随Na₂CO₃浓度的升高显著提高;郑单958杂交种的耐盐碱性优于自交系。     

玉米杂交种苗期耐盐碱筛选与大田鉴定的比较分析

基于所确定的玉米苗期耐盐碱筛选最宜浓度和适宜的生理生化指标,对14个吉林省主推玉米杂交种进行苗期盐碱耐性分析和大田鉴定。结果表明:大田鉴定结果与苗期耐盐碱能力综合评价分级基本吻合;苗期盐碱耐性弱的杂交种其大田减产明显,其减产率最高为44.12%,最低为17.39%,证明鉴定方法与评价指标科学有效,并可以初步筛选剔除一些苗期胁迫表现弱的材料;对于苗期胁迫耐盐碱能力综合评价表现较强的杂交种,其大田减产率变化幅度不大,变化范围在9.33%～11.76%,具体品种是否适宜盐碱地种植需经进一步的大田鉴定。     

不同玉米杂交种耐盐碱性鉴定

在不同盐碱含量的试验地,通过整个生育期对供试材料耐盐碱指标进行测定,评价不同玉米杂交种的耐盐碱性,并对供试材料的耐盐碱性划分等级。研究结果表明,成株率耐盐碱指数与出苗率、最终产量耐盐碱指数均呈正相关关系,且均达显著水平。开花散粉期较短的ASI和较高的成株率、生殖生长期较多的绿色叶片数和穗粒数是耐盐碱性较高的品种获得高产的基础。与其他杂交种相比,辽1127和铁研39不仅表现出较高的耐盐碱性,且具有良好的生产潜力。     

高淀粉玉米杂交种“四单19”丰产性、稳定性及适应性分析

根据1989～1990两年吉、黑两省玉米区试汇总材料进行稳定性分析，采用适应性参数和回归系数作为判断标准，对于品种的丰产性、适应性采用联合方差分析方法，结果四单19、本育9号、白单16、九单12等表现丰产，四单16、龙140较丰产，四单19、四单73、吉单141、龙131、龙141等稳定性好，四单19适应性广，可代替四单8号种植．     

玉米杂交种异地种植稳产性差异类型分析

为加快杂交玉米品种更新步伐、提高粮食产量、实现农业增效、农民增收的目的,针对建平地区的气候特点及土壤条件,进行优质、高产、抗逆性强、稳产杂交玉米新品种的筛选研究。     

La3+对玉米渗透胁迫缓解效应的研究

La³⁺能缓解渗透胁迫下玉米幼苗叶片渗透势的降低，增加脯氨酸的含量，使膜脂过氧化产物丙二醛（MDA）在叶片中的积累减少，并且抗旱品种和不抗旱品种之间表现出明显的差异．     

我国玉米杂交种耐旱性评价与分析

以我国目前生产应用的玉米杂交种为材料,在干旱处理和浇水(对照)条件下,根据成熟期产量和产量构成因素的耐旱指数分析其耐旱性。以耐旱指数为依据将供试材料分为高、中、低3种抗旱类型,表现高抗旱的材料有成单30、川单21、川单25、川单27、丹玉39、登海9、高农901、冀玉9、晋单42、农大108、强盛31、先玉335、新丹2100和豫玉26;表现中抗旱的材料有东德9号、吉单209、浚单20、蠡玉16、临奥1号、鲁单9002、鲁玉13、农大3138、强盛5、铁单10、秀青73-1和中单2号。不同材料的耐旱性表现不同,不同性状的耐旱性也表现不同,说明玉米耐旱性改良具有较大潜力。     

18份大豆品种耐盐碱性筛选与综合鉴定

采用水培方法,用60 mmol·L^-1混合盐(NaHCO_3∶Na_2CO_3的摩尔比为9∶1)溶液,对18份大豆品种的幼苗进行盐碱胁迫。处理7 d后,测定株高、茎粗、叶面积、主根长、地上干重、净光合速率(Pn)、胞间CO_2浓度(Ci)、蒸腾速率(Tr)和气孔导度(Gs)等指标,通过主成分分析法和模糊数学隶属函数法对18份大豆品种进行耐盐碱性综合评价,并进行聚类分析,筛选出相对耐盐碱的大豆品种,从而为盐碱地大豆品种的应用提供理论依据。结果表明:经主成分分析,株高、主根长和净光合速率(Pn)的负荷量最大,可作为衡量大豆耐盐碱性与品种筛选的主要指标。不同品种大豆材料经过模糊数学隶属函数法进行耐盐碱性排序,品种间耐盐碱性表现出明显差异,最后通过聚类分析,18份大豆品种可以被分为三大类,其中杂交豆5号等4个品种为耐盐碱品种,吉育611和吉育299等11个品种为中等耐盐碱品种,吉育256和东农63为盐碱敏感品种。     

镉胁迫下水稻SOD活性和MDA含量的变化及其基因型差异

以4个水稻品种为材料,采用土培试验,研究了不同土壤镉浓度对水稻超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量的影响,水稻叶片SOD活性和MDA含量在生育进程中的变化,以及SOD活性和植株镉含量的关系。结果表明： 1）轻度镉胁迫有利于提高水稻的SOD活性,而高浓度镉胁迫对水稻的SOD活性有抑制作用;MDA含量与SOD活性存在负相关关系,随着土壤镉浓度的增加,MDA含量先下降后上升。2）在水稻生育过程中,SOD活性分蘖期>乳熟期>齐穗期;MDA含量随生育期一直增加。3）镉胁迫对水稻叶片SOD活性的影响存在基因型差异,分蘖期不同水稻基因型间SOD活性的差异最大。4）水稻的SOD活性与植株和稻米的镉含量呈负相关,齐穗期的SOD活性与镉含量的相关性达显著水平。     

玉米杂交种子粒干物质积累速率差异分析

以黑龙江省玉米生产上常用的12个杂交种为供试材料,分析灌浆后期品种间子粒干物质积累速率的差异。结果表明:玉米杂交种吐丝后40～65 d百粒重增长符合Logistic曲线;子粒平均干物质积累速率差异显著,其中四密25最高,为0.558 g/(d.100粒);四单19最低,仅为0.433 g/(d.100粒);从大到小依次为四密25>东农250>白单9号>本育9>中单2号>吉单180>庆单2号>丰禾10>龙单21>久龙1号>四单16>四单19。各杂交种最大干物质积累速率集中在吐丝后40～45d和50～55d两个阶段。     

外源多胺与玉米的耐旱性

本文研究了外源多胺(精胺、亚精胺、腐胺)与玉米耐旱性的关系。结果表明，外源多胺处理降低了水分胁迫下玉米叶片细胞膜透性增加的程度和膜脂过氧化程应，并延缓了玉米叶片叶绿素和可溶性蛋白质含量的下降．这些结果说明外源多胺在减轻或抵御自由基伤害，在增强玉米耐旱性上具有相当明显的效果．研究还表明，在增强玉米的耐旱性上，三种多胺的效果依次为精胺(四胺)、亚精胺(三胺)、腐胺(二胺)．     

The maize late embryogenesis abundant protein Zm DHN13 positively regulates copper tolerance in transgenic yeast and tobacco

Late embryogenesis abundant (LEA) proteins accumulate in the late stage of plant seed development, and are upregulated in most plants during drought, cold, heat, or salinity stress. LEA proteins can be classified by amino-acid sequence into seven groups. Dehydrins belong to LEA protein group Ⅱ. In previous studies, the maize KS type dehydrin ZmDHN13 increased the tolerance of transgenic tobacco to oxidative stress. In the present study, ZmDHN13 was identified under copper stress conditions, and the protein was then characterized using transgenic yeast and tobacco plants to investigate its functions. ZmDHN13 bound Cu2+. Its overexpression in transgenic tobacco conferred tolerance to copper stress by binding metals and reducing the accumulation of reactive oxygen species (ROS). Three conserved domains displayed a cooperative effect under copper stress conditions.     

Diallel analysis of aflatoxin accumulation in maize

Since its discovery in numerous feedstuffs, aflatoxin, a carcinogenic compound produced by the fungus Aspergillus flavus Link ex Fries, has caused much concern among consumers and producers alike. This toxin poses a serious economic threat to maize (Zea mays L.) producers of the southeastern and midwestern regions of the United States. Efforts to identify maize germplasm that is resistant to aflatoxin accumulation and to investigate the genetic basis of this resistance have been undertaken at numerous research institutions. The objectives of this study were to (1) evaluate aflatoxin accumulation in grain harvested from maize inbred lines and a diallel cross among these lines, (2) determine the importance of general and specific combining abilities in inheritance of resistance to aflatoxin accumulation, and (3) estimate general and specific combining ability effects associated with resistance to aflatoxin accumulation in the inbred lines and crosses among them. Eight inbred lines and a diallel cross of the maize lines were inoculated with an A. flavus spore suspension 12–14 d after silk emergence. Following harvest, aflatoxin content was determined from samples of grain. Statistical analyses performed using SAS general linear models (GLM) and DIALLEL-SAS indicated that general and specific combining ability were significant sources of variation in the inheritance of resistance to aflatoxin accumulation. The inbred line Mp313E, which was developed and released as a source of resistance to aflatoxin contamination, had significantly lower aflatoxin accumulation than other lines. Mo18W exhibited excellent general combining ability for reduced aflatoxin accumulation when crossed with the other lines. Both Mp313E and Mo18W could be useful in breeding programs to develop aflatoxin-resistant maize hybrids. Mp339, SC212M, and Ab24E demonstrated aflatoxin susceptibility as both inbreds and in single crosses.     

干旱胁迫对玉米产量和品质的影响研究

干旱胁迫不仅影响玉米生长发育和产量,而且影响了玉米的子粒品质。研究结果表明,干旱胁迫对玉米产量的危害顺序为开花期干旱＞孕穗期干旱＞灌浆期干旱。干旱胁迫虽降低了玉米子粒产量,但使子粒有效养分含量提高。灌浆期干旱胁迫使子粒蛋白质中的各种氨基酸含量提高,孕穗期干旱胁迫使子粒蛋白质中的必需氨基酸含量下降。干旱胁迫使子粒脂肪中不饱和脂肪酸含量下降,饱和脂肪酸含量提高。     

Diallel analysis of fumonisin accumulation in maize

Contamination of maize (Zea mays L.) grain with aflatoxin, produced by the fungus Aspergillus flavus Link: Fries, or fumonisin, produced by the fungus Fusarium verticillioides (Saccardo) Nirenberg (Syn F. moniliforme Sheldon), greatly reduces its value and marketability. Host resistance to fungal infection and mycotoxin accumulation is considered a highly desirable way to reduce losses of both aflatoxin and fumonisin. Maize germplasm lines with resistance to aflatoxin accumulation have been developed in Mississippi. Three of the aflatoxin-resistant lines and five additional lines were used as parents to produce a diallel cross. The diallel cross was evaluated for fumonisin accumulation in field tests conducted in Mississippi in 2007 and 2008. General combining ability (GCA) was a highly significant source of variation in both 2007 and 2008, but specific combining ability (SCA) was not significant. GCA effects for reduced fumonisin levels were highly significant for Mp715, Mp717, and GA209. Mp715 and Mp717 were developed and released as sources of resistance to aflatoxin contamination and exhibit resistance as inbred lines and in hybrid combinations. These lines should be useful in developing maize lines and hybrids with resistance to both fumonisin and aflatoxin accumulation in grain.     

油菜杂交种宁杂21号及其双亲苗期在盐胁迫条件下差异表达基因分析

为了解甘蓝型油菜杂种优势在盐胁迫中的表现,遏制减产,以油菜强优势杂交种宁杂21号及其亲本为材 料,通过转录组测序,筛选鉴定得到1078个芽苗期差异表达基因（DEG）与耐盐杂种优势密切相关,并能被已有盐胁 迫相关QTL注释,部分基因的表达能被荧光定量PCR验证,说明所得DEG具有可靠性,有潜在的油菜耐盐育种价 值。杂交组合中耐盐杂种优势相关DEG表达模式与母本更为类似,大部分表现为正调控,功能倾向于生物合成的 同化作用,而表达模式类似父本的DEG其功能倾向于氧化还原等调节作用。本研究还对耐盐性杂种优势特异的 SNP位点进行了预测和注释,以期为杂交油菜耐盐分子标记的开发以及耐盐育种提供理论依据。     

玉米C型胞质雄性不育系C联848败育的生理机制初探

以玉米C型雄性不育系C联848及其保持系H19为研究对象,对两者叶片中超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性,丙二醛含量进行研究比较。结果表明,C联848的花药都不外露,形状瘦小萎缩,饱满度较差,剥开花药未发现花粉粒存在,通过碘染镜检未发现可育花粉粒,不育系C联848经多年多季种植,在不同世代,未发现有可育植株存在。在生长发育的各个时期不育系叶片中超氧化物酶(SOD)活性都低于保持系。从苗期至拔节期,不育系与保持系叶片中过氧化物酶(POD)活性都略有上升,差异并不显著;当玉米由营养生长转入生殖生长,不育系叶片中的POD活性迅速上升,且与保持系差异显著,并且不育系叶片中的POD活性始终都高于保持系;在玉米转入生殖生长后,不育系叶片中的过氧化氢酶(CAT)活性增长缓慢,远低于保持系中CAT的活性,且在吐丝期两者差异最为显著。玉米生长发育的各个时期,不育系叶片中的丙二醛(MDA)含量均高于保持系,在抽雄期差异最为显著。     

干旱胁迫对春大豆开花期根系生理特性的影响

为明确大豆根系生理特性的变化与抗旱性的关系,在盆栽条件下,以3个抗旱性不同的大豆品种为材料,测定开花期根系相对含水率、根系活力、丙二醛含量、超氧化物歧化酶和过氧化物酶活性.结果表明:大豆根系相对含水率及根系活力随干旱胁迫程度增强而降低,抗旱品种降低程度小于不抗旱品种;根系丙二醛含量随干旱程度的增加而升高,各品种间无明显差异;抗旱品种超氧化物歧化酶活性随干旱程度的增加而升高,而不抗旱品种则表现为先升高后降低趋势;过氧化物酶活性各品种间随着干旱胁迫程度的加强均呈先升高后降低趋势,抗旱品种变化更为明显.干旱胁迫下大豆通过改变根系内部的生理变化以提高其抗旱性.     

SSR-based and grain yield-based diversity of hybrid maize in Thailand

Commercial hybrid maize varieties are often used to extract new inbred lines in hybrid breeding programs. Seven commercial hybrid maize varieties were crossed in a diallel design, and the resulting hybrids and selfed progeny were evaluated for yield and adaptability grown in six locations in Thailand. The parental varieties were analyzed with a set of 64 Simple Sequence Repeat (SSR) loci, spanning all 10 chromosomes. The average number of alleles per SSR locus was 4.98 with a range of 2–11. The polymorphic information content (PIC) varied from 0.24 to 0.89, with an average of 0.69. Using SSR-based genetic distance (GD), an UPGMA dendrogram showed seven field corn varieties classified into three distinct groups. Troyer's genetic distance (TGD) calculated from yield data, which is a function of inbreeding depression, varied from 0.493 to 1.015 between different parental combinations. A significant positive correlation was found between the GD and TGD across the six locations (0.66^**). The GD correlated positively with specific combining ability (SCA) as well across all locations (r = 0.76^**) heterosis was significant for grain yield and SCA, accounting for 47% of the sum of the square among entries. Therefore, we suggest that broad base populations derived from each of the distinct groups can be formed using combined criteria of SSR-based GD, TGD, grain yield, GCA and SCA.     

高产杂交种组配中马齿型亲本的选择与利用

近十年来,我国玉米育种有两个重要的变化,一是含有热带、亚热带种质的国外杂交种引入,二是群体改良工作取得进展。各地育种家从这两类材料中选获了不同类型的自交系,为组配高产强优势组合创造了条件。本文就是以具有国外血缘的硬粒型自交系与改良群体中选出的马齿型自交系为材料,进行双列杂交试验的结果,评价了马齿系在组配高产杂交种中的作用。试验结果表明,马齿系金黄96B是一个配合力较高、综合性状较好的亲本,可在今后育种中进一步加以选择利用。