玉米子粒主要营养成分在杂交后代的表现

以10个普通玉米自交系及其90个F2正反交组合在两个地点的试验数据,研究了子粒3种营养成分包括蛋白质、淀粉和油分含量的杂种优势、细胞质效应和亲子关系.结果表明:(1)蛋白质含量表现负向杂种优势,淀粉含量表现正向杂种优势,而油分含量则主要表现正向超低亲优势;(2)子粒3个营养成分不存在细胞质效应;(3)杂交种蛋白质、淀粉和油分含量与双亲均值存在最大的表型相关,其相关系数(r)分别为0.602* *～0.531* *、0.520* *～0.620* *和0.566* *～0.370* *.     

玉米籽粒铁含量杂种优势及相关分析

以16个玉米自交系,以及将其按Griffing方法4组配的120个杂交组合为供试材料,进行玉米籽粒铁含量杂种优势、亲子相关以及籽粒铁含量与主要农艺、经济性状和品质性状的遗传相关分析。结果表明,杂交种籽粒铁含量以超低亲杂种优势为主,也出现中亲优势和超高亲优势为正值的一些组合。杂交种籽粒铁含量与母本、父本、高值亲本、中亲和高低值亲本之差的相关均达正向极显著水平,与低值亲本的相关达正向显著水平。铁含量与蛋白质、轴重和单株产量的遗传相关达正向极显著水平,与穗重的遗传相关达正向显著水平,与淀粉和油分的遗传相关表现为微弱的负相关和正相关,与穗位高的遗传相关达负向极显著水平。     

利用近红外透射分析仪快速测定玉米子粒品质的初步研究

对425份玉米自交系和1125份杂交组合的子粒品质进行测定，并对粗脂肪、蛋白质、粗淀粉的杂交优势和亲本的相关性作了探讨。结果表明，3种成分在不同材料存在显著差异，粗脂肪和蛋白质变幅和变异系数都较大，粗淀粉含量变幅和变异系数都较小，自交系中平均含量分别为4．24％，12．17％和71．10％，杂交组合中平均含量分别为4．86％，9．93％，72．56％。458个杂交组合子粒的3种成分含量与亲本的相关性均较低，粗脂肪的中亲优势和超亲优势均表现较大的正向，蛋白质均表现为负向优势，粗淀粉的杂交优势变异幅度较大，平均正向杂交优势较小。     

红叶棉花的产量杂种优势研究初探

利用综合性状表现较好的3个红叶材料作父本,与15个绿叶转基因棉花新品种(系)组配19个红叶杂交组合,研究了具有红叶标记性状棉花的产量杂种优势表现,结果表明:19个红叶杂交组合子棉产量具有明显的杂种优势,皮棉产量的具有正向中亲优势、正向超亲优势和负向竞争优势,衣分和单铃重具有正向的中亲优势,单株铃数表现正向中亲、超亲和竞争优势,筛选出产量竞争优势在5%以上、综合性状较好的优势组合4个。     

光子棉花的产量杂种优势研究

利用综合性状较好的5个光子材料作亲本,与17个优良毛子棉花新品种(系)组配19个光子杂交组合,研究具有光子标记性状杂交组合的产量杂种优势表现.结果表明:光子杂交组合皮棉产量表现正向中亲优势和正向超亲优势,籽棉产量光子作母本的杂交组合杂种优势高于光子作父本的杂交组合;衣分和单铃重表现正向中亲优势,单株铃数光子作母本的杂交组合优势率高于作光子父本的杂交组合;籽指表现负向中亲优势、负向超亲优势和负向竞争优势,筛选出产量竞争优势5%以上、综合性状突出的优势组合8个.     

玉米杂交种与亲本主要光合性状的比较

对５在自交纱及其组配的４个杂交种光合性能的分析表明，杂交种较其亲本在光合面积上表现三种关系类型即居中，偏高亲，超高亲，而在光合时间上表现为负优势；在光合速率上表现为正优势；幅度在３．１％～２３．４％，超高亲２．４％～９．３％，光合速率杂种优势与叶绿素含量有关。杂交种的叶绿素ａ／ｂ和胡萝卜素／叶绿素较亲本有降低的趋势。结合产量及有关性状分析表明，杂交种较自交系不仅在源上而且在库系统均有明显改善。     

杂种小麦光合特性杂种优势的日变化研究

为阐明杂种小麦光合特性杂种优势的日变化规律以及和环境因子的相互关系,本研究以普通小麦杂交种‘陕垦6号’及其亲本为材料,采用Li-6400光合作用测定仪分别测定了开花期、灌浆前期、灌浆中期、灌浆后期的光合参数,然后对各参数的杂种优势进行了计算与分析。研究表明净光合速率和气孔导度的杂种优势在开花期最弱,灌浆中期最强。在灌浆前期,净光合速率在上午为正向杂种优势,下午为负向杂种优势。气孔导度则上午为负向杂种优势,下午为正向杂种优势;蒸腾速率的杂种优势在灌浆前期最弱,灌浆中期最强。水分利用效率的杂种优势在开花期最弱,在灌浆前期表现最强,到了灌浆后期又开始下降。灰色关联度分析表明小麦光合杂种优势的主要环境影响因素是大气CO2浓度。所以宜在灌浆中期进行高光效品种的选育,可以有效的发挥小麦的光合杂种优势,同时在不同时期合理利用水分利用效率进行田间管理。     

玉米雄穗分枝数性状遗传、杂种优势与亲子相关分析

以15个玉米F1代杂交种及8个亲本自交系为材料,在两种氮环境下研究了玉米雄穗分枝数的遗传力、杂种优势及亲子关系等。结果表明,玉米雄穗分枝数性状存在显著的基因型和基因型×氮水平互作差异,广义遗传力达0.52～0.86。该性状F1杂交种呈近中亲遗传和超显性遗传共存的特点,大多数组合表现出正向杂种优势。亲子相关分析表明,F1雄穗分枝数与父本、高亲值及中亲值之间相关性较高。研究结果为玉米育种关于雄穗分枝性状选择提供了一定的参考。     

维权台

济宁市百丰农艺研究所郑重声明,玉米品种农大108,神玉糯1号（宁粘2号）,四川西南科联种业律师声明,杂交水稻品种Ⅱ优1577,Ⅱ优98（神州2号）,兴垦3号（垦339）玉米杂交种，中国农业大学、承德裕丰种业有限公司郑重声明，杂交玉米中原单32，玉米新品种潞玉13号（长玉13），K优818（神州3号），     

维权台

玉米新品种“潞玉13（长玉）13”的维权公告，中国农业大学、承德裕丰种业有限公司郑重声明，四川西南科联种业律师声明，杂交水稻品种Ⅱ优1577，Ⅱ优98（神州2号），济宁市百丰农艺研究所郑重声明，玉米品种农大108，神玉糯1号（宁粘2号），兴垦3号（垦339）玉米杂交种，杂交玉米中原单32，K优818（神州3号），     

利用SSR标记快速鉴定玉米杂交种农大108和豫玉27的种子纯度

本文利用SSR标记技术分别筛选出玉米杂交种农大108和豫玉27的特异性引物,结合单籽粒DNA快速提取方法,建立了两个品种的种子纯度鉴定试剂盒.实验表明,应用此试剂盒可快速、有效地鉴定两个杂交种的种子纯度.     

Leaf Anatomy of Maize Inbred Lines and Crosses at Extreme Temperatures for Active Growth

Inbred lines and crosses from cool temperate regions (C) and from warm regions (W) were grown at 14, 22, 30 and 38°C up to the same physiological age, the full expansion of the third leaf. The laminae of the second leaf were studied for anatomical traits. For all traits the genotypic variability was high over the whole temperature range, but the rank order was influenced by temperature. Leaf thickness and cross sectional area of epidermal cells were smallest at 22°C. Stomatal frequency increased in inbred lines from 14 to 38°C and in crosses from 30 to 38°C. In crosses stomatal length was low at 22°C and high at 38°C while inbred lines either did not react to temperature at all (C) or had low to very low values over the whole temperature range (W). Cross sectional area of chlorenchyma cells (mesophyll, bundle sheath) was high at 14°C. For mesophyll cells of inbred lines and generally for bundle sheath cells a second maximum occurred at 30°C. Cross sectional area of both chloroplast types was high at 14°C and low at 22 or 30°C. Positive heterosis was seldom observed but negative heterosis occurred for chlorenchyma cell size at 14°C. This might indicate an improved fitness for photosynthesis at suboptimal temperature because of small cells, especially as W-genotypes generally had large cells at this temperature. A negative heterosis for the stomatal frequency over the whole temperature range might stand for a good fitness of hybrids for photosynthesis, too.
The investigations have shown that the expression of some important anatomical traits is dependent on temperature as well as on origin and genetic structure of maize genotypes.     

西南骨干玉米自交系主要农艺性状和产量正反交杂优效应分析

为了比较玉米自交系主要农艺性状和产量的正反交杂优效应,以9份西南地区骨干玉米自交系组配的72份单交种为材料,采用随机区组试验,对自交系及其正反交杂种F1代主要农艺性状和产量进行比较研究。结果表明,正反交效应对不同玉米自交系杂种F1代主要农艺性状和产量的影响不同;T检测表明,大多数玉米自交系正反交杂种F1代主要农艺性状和产量差异不显著。玉米自交系海9-21、5003、478正反交杂种F1代在穗粗、百粒重、单穗粒重、穗下茎节强度及穗位高等性状上差异显著或极显著。由此得出,不同自交系正反交杂种F1代在主要农艺性状和产量上具有不同的杂种优势,其中穗位高/株高具有负向杂种优势。由于玉米穗位高/株高具有负向杂种优势,即杂种F1代穗位高/株高值较自交系有所降低,因此在自交系选育时,不宜对亲本材料过分追求低的穗位高/株高。     

玉米杂交种及其亲本苗期性状对低氮胁迫的动态响应

以玉米杂交种先玉335及其亲本（PH6WC、PH4CV）和豫玉22及其亲本（综3、87-1）为试验材料,通过水培方法,设置低氮（0.04mmol/L,LN）和正常氮素（2mmol/L,CK）水平2个处理,分别在培养3、7和14d后,对其幼苗生物量积累、叶片和根系表型、叶绿素及氮素含量等进行分析,探究低氮胁迫下玉米杂交种及其亲本幼苗性状的动态变化。结果表明,玉米苗期根系对低氮的响应要早于地上部,且杂交种对低氮的响应比亲本更为迅速。在CK和LN处理下,杂交种幼苗的多个性状均存在中亲和超亲优势,豫玉22的根尖数、根系氮积累量占比和先玉335的总根长、根表面积及根尖数的杂种优势在3个时间点与CK处理相比均有较大幅度提高。通过耐低氮指数分析发现,杂交种的耐低氮能力介于2个亲本之间或与其中1个亲本接近。     

干旱区不同品种中华钙果光合特性比较研究

不同中华钙果品种在西北干旱区叶片形态及光合特性的研究可为该区域高产优质节水品种筛选提供理论依据。通过测定叶片光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和胞间CO₂浓度(Ci)等光合性能指标及形态,分析不同中华钙果品种的叶片形态特征与光合特征及其相关关系。结果表明：（1）不同中华钙果品种叶长和叶宽均存着较大差异,叶面积大小表现为‘农大5号’>‘农大7号’>‘农大6号’>‘生态晚熟种’>‘生态早熟种’;（2）‘农大7号’的净光合速率及蒸腾速率均最大,其净光合速率显著高于‘农大6号’和‘生态早熟种’,蒸腾速率均显著高于其他品种,5种中华钙果的气孔导度及胞间CO₂浓度均无显著性差异;（3）5种中华钙果净光合速率、蒸腾速率、气孔导度与叶面积之间存在正相关线性关系,胞间CO₂浓度与叶面积之间存在负相关线性关系;（4）5种中华钙果的光合速率与气孔导度、蒸腾速率、叶片蒸汽压亏缺、叶片温度呈极显著正相关,与胞间CO₂浓度呈极显著负相关。     

Heterosis,molecular diversity,combining ability and their interrelationships in short duration maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) across the environments

Five inbred lines, 10 single cross maize (Zea mays L.) hybrids and two standard cultivars as check were used to study the combining abilities and heterosis under three environmental conditions. Random amplified polymorphic DNAs (RAPDs) markers were used to study the genetic diversity (GD) and further to analyze relationship of RAPDs based GD with combining ability and heterosis in short duration maize. Spearman’s rank correlation coefficients and linear regressions were analyzed to identify the most important factor determining heterosis and per se performance of the hybrids. Variances due to general combining ability (GCA), specific combining ability (SCA) and their interactions with environment were found to be significant. Twenty random primers generated 179 RAPD fragments. Of these, 102 RAPD fragments were polymorphic. GD was determined using Jaccard’s similarity coefficient, and a dendogram was constructed by UPGMA cluster analysis. The RAPDs based GD exhibited non-significant negative or positive association, non-significant linear regression along with very low coefficient of determination (R ²) with SCA, high and mid parent heterosis (HP and MP) and per se performance of the hybrids. Significant positive correlations and regressions along with high coefficients of determination were recorded for SCA with HP, MP and per se performance of the hybrids. The HP and MP also established significant positive association and linear regression along with high coefficient of determination with per se performance of hybrids whereas the parental mean did not establish any significant correlations with the GD, HPH, MPH and grain yield of F₁s. The present investigation, therefore, did not find any role of RAPDs based GD in determining hybrid heterosis and hybrid performance in short duration sub-tropical maize. The SCA, however, has emerged as the most important factor in determination of heterosis as well as per se performance of the hybrids in short duration maize.     

Relationship between heterosis and genetic distance based on morphological traits and AFLP markers in pepper

Genetic diversity is considered as one of the criteria for the selection of parents for hybrid breeding. The present study was undertaken to evaluate genetic divergence among seven pepper cultivars and to assess the relationship between heterosis and parental genetic distance. Twenty‐one F₁ hybrids and seven parents were evaluated for 15 morphological characters in a greenhouse and in the field. The parents were examined for DNA polymorphisms using six amplified fragment length polymorphism (AFLP) primer combinations. Cluster analysis using two genetic distance measures grouped the seven parents differently. Mid‐parent and high‐parent heterosis was observed for most characters. Most hybrids outperformed the parental lines for fruit yield, earliness and plant height. Morphological and AFLP‐based distance measurements were efficient enough to allocate pepper genotypes into heterotic groups. The correlations of morphological distances with mid‐parent heterosis were significant for days to flowering and maturity, suggesting earliness can be predicted from morphological distances of parental lines. However, the correlations of AFLP‐measured genetic distances with mid‐ and high‐parent heterosis were non‐significant for all characters, except for fruit diameter, and proved to be of no predictive value.     

三个转Bt基因抗虫杂交棉杂种优势的解剖学分析

选取湘杂棉3号、南抗3号和鲁棉研15等3个大面积推广的强优势转Bt基因抗虫杂交棉及其亲本为材料,剖析盛花期主茎功能叶（倒4叶）的叶片结构、叶表皮气孔特征以及主茎功能叶的叶脉、叶柄、铃柄和对应的果枝叶叶柄等器官的维管束组织结构。结果表明,3个F1及亲本共9个材料的主茎功能叶（倒4叶）主叶脉中的维管束形态有三分支型、两分支型和无分支型3种,杂种及亲本之一的维管束都为三分支型,说明三分支型的维管束是显性遗传。F1功能叶主叶脉、功能叶叶柄、果枝叶叶柄、铃柄的维管束性状（导管总数、单个导管面积、维管束总面积、维管束组织比）和叶片厚度、叶片栅栏细胞大小的优势表现因组合而异。主叶脉、功能叶叶柄、果枝叶叶柄、铃柄的维管束以及叶片厚度、叶片栅栏细胞大小的优势与杂种的产量优势可能没有关系或相关性较小。3个F1的下表皮单位叶面积气孔总面积均表现超亲优势。果枝叶可能比主茎功能叶对铃的发育影响更大。     

Heterosis and Genetic Variances and their Implications for Breeding Improved Varieties of Spring Beans (Vicia faba L.)*

Handcrosses were made in a factorial manner with 24 Vicia faba inbred lines m three sets, each between four male and four female parents. The resulting 48 hybrids, their parental inbreds and three commercial varieties were grown in performance trials during the years 1985—87 with three replications at one location. Yield and yield components were recorded on single plant basis. The average superiority of the hybrids above the control varieties was 26 % in plant yield. The best crosses outyielded the controls by more than 50 %. However, a few inbred lines also reached, the yield level of the controls. The average heterosis was significant for all characters except for maturity date. In plant yield the average heterosis was 75%, ranging between 34% and 148% in the various cross combinations. The highest average heterosis of 110 % was observed in yield at the lateral stems. In all characters the best inbreds were superior to the lower hybrids and in some characters even equal to the average of the hybrids. A strong positive relationship was found for all characters between hybrid performance and mid-parent value and between the per se performance of the inbreds and their general combining ability. Genotypic differences between the hybrids as well as between the inbreds were highly significant. Most of the variability between the hybrids in all characters were attributed to general combining, ability with only little evidence for specific combining ability. In the discussion the results are evaluated according to the choice of the breeding category of the partial allogamous faba bean species.