玉米杂交种穗部产量性状灰色关联度分析

应用灰色关联度分析方法．对玉米杂交种穗部产量性状间的相关性进行了分析。结果表明：与玉米杂交种单穗粒重最为相关的性状是穗粒数．与单穗粒重关联度高的还有穗长、行粒数、粒深等,而其他几个穗部性状如轴粗、穗行数、穗粗、百粒重、秃尖、粒厚等与其关联度也较高。玉米杂交种穗部产量性状间具有复杂的相互关系。     

中国农家玉米品种性状变异研究

研究了我国主要农家玉米品种的生育期、主茎叶数、株高、茎粗、穗位、穗长、穗粗、穗行数、行粒数、穗粒重、千粒重及出籽率12个数量性状的变异情况,并对其株型、穗型、穗轴颜色、子粒类型及子粒颜色5个质量性状变异进行了简要分析.我国农家玉米品种数量性状的变幅较大,特别是株高、穗粒重和穗位等性状.同时,农家品种也具有它们独特的优异性状,对于育种材料改良有着重要意义。     

玉米穗部产量性状杂种优势分析

研究了玉米穗部性状的杂种优势,双亲生育期间隔长短与F1穗粒重的关系以及穗部性状亲子相关.结果表明:穗粒重、穗重的杂种优势最大,其次为穗粒数、千粒重、穗长、穗粗,穗行数为最小.F1穗粒重杂种优势与双亲生育期间隔长短无关.杂交种穗粗、穗行数与母本穗粗、穗行数以及中亲值呈正相关,杂交种千粒重与中亲值呈正相关。     

含非洲血缘玉米杂交种主要穗部性状与单株产量的相关及通径分析

主要对8个含非洲血缘的玉米杂交种主要穗部性状与其单株产量之间了进行相关和通径分析。相关分析表明,各穗部性状与单株产量之间均呈显著正相关,相关关系由大到小依次为百粒重、行粒数、穗长、穗行数、穗粗。通径分析结果表明:各穗部性状对单株产量的相对重要性依次为百粒重、穗长、穗行数、穗粗、行粒数。因此,为了获得含非洲血缘的高产玉米杂交种,应着重选择百粒重较大、穗长较长和穗行数较多的基因型,而对于穗粗和行粒数的选择标准可以放宽。     

玉米穗部性状的遗传性研究

采用增广NCⅡ设计,对玉米穗部性状进行了杂种优势、配合力分析及遗传模型测验。结果表明:穗粒重的杂种优势最大,穗行数的优势最小。所研究的5个性状均以加性基因效应为主,对穗行数、行粒数和穗粒重可在早代进行选择,对穗长和穗粗不宜进行早代选择。5个穗部性状均不符合加性-显性遗传模型,穗长存在着明显的加性效应;穗粒重、行粒数除显性效应外,还存在明显上位性效应;穗粗和穗行数存在着显著的显性效应,上位性效应不明显。     

夏玉米穗部性状的遗传相关与通径分析

通过对44个夏玉米杂交种穗部6个主要性状与单株粒重遗传相关与通径分析表明：穗长与穗粗在影响单株子粒产量诸因素中占据主导地位,在对穗长、穗粗重点选择的基础上,考虑对穗行数、行粒数、出子率的选择,容重可独立进行选择。穗部性状的选择必须考虑性状间的相互制约关系,综合利用某一穗部性状对单株粒重的直接效应和通过其他性状的间接效应。     

灰色关联度分析在玉米组合鉴定试验中的应用

应用灰色关联度分析方法,对玉米组合鉴定试验中主要参试品种的产量、株高、穗位高、茎粗、穗长、穗粗、轴粗、秃尖长、穗行数、行粒数、千粒重、出籽率和单株粒重等性状相关性进行了分析。结果表明:玉米产量与各性状的关联度由大到小依次为:单株粒重>穗粗>出籽率>轴粗>茎粗>千粒重>穗行数>行粒数>穗长>株高>穗位高>秃尖长。因此,在玉米组合鉴定试验中,要注重选择单株粒重高、穗比较粗、出籽率比较高和茎比较粗的品种,而对于株高、穗位高和秃尖长可适当放宽要求。     

玉米4个穗部性状的遗传及相关分析

选用10个优良玉米自交系配成不完全双列杂交组合,研究玉米穗长、穗粗、穗行数、百粒重4个穗部性状的遗传效应及其相关性。结果表明,穗长、穗粗、百粒重主要受遗传主效应控制,穗行数受基因型×环境互作效应的影响。穗长和穗粗主要受胚加性效应的影响,其胚加性方差(VAo)分别占遗传主效应方差(VG)的92.56%、95.80%;穗行数的遗传受母体加性互作、胚加性互作的共同影响,两种效应依次占环境互作效应的50.31%、49.60%;百粒重受胚乳加性和母体加性效应的共同控制,两种效应分别占遗传主效应的50.73%、47.12%。穗长和穗粗以胚普通遗传率为主,穗行数以胚乳和母体互作遗传率为主,百粒重以胚乳普通遗传率和母体普通遗传率为主。穗长与穗粗、穗行数,穗粗与穗行数的胚加性(rAo)、细胞质(rC)均呈极显著高度正相关,穗长与百粒重的细胞质(rC)呈极显著正相关,穗粗与百粒重的细胞质(rC)、母体显性(rDm)、胚加性互作(rAoE)、细胞质互作(rCE)均呈极显著正相关,穗长与穗粗、穗长与穗行数、穗长与百粒重、穗粗与穗行数、穗粗与百粒重5对性状可以同步改良。     

华北地区不同年代玉米杂交种主要农艺性状演变规律研究

通过对我国华北地区1970-2005年审（认）定的26个玉米单交种的主要农艺性状的分析,认为我国华北地区玉米杂交种主要农艺性状的演变规律为：株型由平展型逐渐向紧凑型和半紧凑型过渡;产量稳步提高;穗长、穗粒数和行粒数增多;穗位高有下降趋势;秃尖长和秃尖度有上升趋势;千粒重、株高、穗行数、穗粗、出子率、ASI和成熟期等性状趋于稳定;产量的绝对杂种优势和相对杂种优势分别呈上升和下降趋势。试验结果认为,千粒重、行粒数、穗粒数和穗行数对提高玉米产量的作用最大,是我国华北地区20世纪70年代以来玉米杂交种提高产量的重要因素。     

我国不同时期玉米主要农艺性状与产量变化分析

利用我国不同时期具有代表性的20个玉米单交种及其32份亲本为材料,采用裂区试验设计,进行产量与主要农艺性状变化的相关分析、通径分析和产量构成主因子分析。结果表明:品种产量和中亲产量随着年代推进逐渐提高,亲本产量与品种产量极显著正相关;产量与穗粗、单株穗干重、单株粒干重、穗轴粗、子粒长、株高、叶片宽、生育期、百粒重、行数和出籽率呈极显著或显著正相关;与穗上叶夹角、雄穗分枝数呈极显著或显著负相关;出籽率、百粒重、穗位高、生育期、穗长、穗行数等对产量增加直接作用最大;穗粗、密度、穗干重、百粒重是产量增加的主要因子。种植密度的提高、株型的改善及果穗性状的优化是玉米产量提高的主要原因。     

玉米矮花叶病研究进展

玉米矮花叶病(Maize Dwarf Mosaic Virus,MDMV)是一种世界性病毒病害,近年来在我国危害越来越重,已经成为玉米产区的主要病害之一。在我国危害玉米生产的主要是MDMV-B株系,至今尚未发现MDMV-A株系。感染MDMV的症状因寄主抗病能力、生育时期及环境条件而不同。根据显症叶片数及叶绿素被破坏的程度,参考病株高度、单株产量等指标,提出了5级分级标准用以记载植株的发病级别。MDMV可以种子传毒,农田杂草为病毒的积累和越冬提供了有利条件,这些初侵染源为病害发生、流行创造了条件。MDMV是一种借蚜虫传播的非持久性病毒,实践证明采取以种植抗病品种为主,辅助以栽培管理的综合防治措施,是防治MDMV的有效途径。目前在我国主要的玉米种质资源中,只有塘四平头和获白系统抗或高抗MDMV,而具有国外或旅大红骨血缘的材料基本感MDMV。国外学者对MDMV-A株系的抗性遗传研究较深入,我国则需加强对MDMV-B株系的抗源筛选及抗性遗传研究工作。     

湖南省玉米生产发展几个问题的商榷

通过湖南省玉米生产发展的历史与现状分析，以及当前粮、经、饲三元结构的分离和粮食生产稳定的需要，指出湖南省玉米在扩大面积、提高单产和增加总量上均有要求，并具有可行性。发展中应着重新品种的选育、引进，特别是抗(耐)旱、耐低氮的品种；简化节水避旱栽培技术研究和建立杂交种子产业，突破制种瓶颈。提出了增加科技投入、加强科研、推广部门协作和推进青贮玉米研究等建议。     

矿质营养对玉米籽粒营养品质的影响

本文介绍了氮、磷、钾、锌、锰、铜、硒及稀土对普通玉米、高赖玉米和甜玉米籽粒营养品质的影响，适量施肥可明显提高籽粒蛋白质、脂肪、氨基酸等成分的含量。单独施氮肥虽然能显著提高蛋白质含量，却降低了蛋白质的营养价值．氮、磷、钾配合使籽粒品质明县改善、普通玉米和高赖玉米籽粒品质对矿质养分的反应有差别．     

Effects of Lactobacillus buchneri isolated from tropical maize silage on fermentation and aerobic stability of maize and sugarcane silages

This study was aimed to perform a screening of Lactobacillus buchneri strains from maize silage and use them as inoculant in maize and sugarcane silages. In all, 151 lactic acid bacteria (LAB) strains were isolated from whole‐plant maize silage, and their identification was based on the sequence analysis of 16S rDNA. In total, 15 strains were categorized to the L. buchneri group and eight of these were selected based on growth rate and fermentation pattern. The selected strains were evaluated on fermentation and aerobic stability of maize and sugarcane silages. For maize, the inoculated silages had lower pH and higher LAB population, but lower acetic acid concentration in comparison with the untreated control silage. For sugarcane silage, the strains 56.1, 56.4 and 40788 resulted in highest dry‐matter (DM) content and lowest DM losses. However, only the strain 40788 showed lowest counts of yeasts and moulds. Sugarcane silages inoculated with the strains 56.9, 56.26 and the untreated control silage showed highest concentrations of lactic acid and ethanol, besides the great DM losses. Even so, for both crops, the aerobic stability was not affected by inoculation. After air exposure, all silages increased temperature and had high population of yeast and moulds. Nevertheless, the strains 56.1 and 56.4 are promising for use as a silage inoculant.     

黄曲霉对花生和玉米的侵染研究

黄曲霉(Aspergillus flavus)极易侵染花生、玉米等多种农作物,并且在侵染后产生具有致癌、致畸、致突变作用的有毒代谢产物——黄曲霉毒素.黄曲霉的侵染和黄曲霉毒素污染不仅发生在作物生长环节,而且在收获、干燥、储运等过程也会发生,严重威胁农产品消费安全和人畜生命健康.因此,解析黄曲霉对粮油作物的侵染过程及侵染...     

Leaf photosynthesis is enhanced in normal oil maize pollinated by high oil maize hybrids

The grain yield of normal oil maize (Zea mays L.) might increase when pollinated by high oil maize (HOM) hybrids because of heterosis. To testify that the grain yield increase might be a result of improved photosynthetic rate and related traits, the normal oil maize (NOM) hybrid, Nongda108, was cross-pollinated by three HOM hybrids, HOM202, HOM115 and HOM4515 (for short as ND108pHOM202, ND108pHOM115 and ND108pHOM4515). We found that the ND108pHOM202 and ND108pHOM115 exhibited higher net photosynthetic rate (P_n), accompanied by larger stomatal conductance (g_s) and transpiration rate (E). Moreover, delayed leaf senescence was observed in their leaves, including larger leaf area index (LAI) and higher Chl content and Chl a/b ratio. Apart from higher phosphoenolpyruvate carboxylase (PEPCase) activity, the soluble proteins were also higher in the two cross-pollinations. The higher leaf photosynthesis could explain the grain increase in ND108pHOM202 and ND108pHOM115. However, ND108pHOM4515 exhibited a decreased photosynthetic characteristic and yield performance. Significantly positive relation between grain yield and biomass (r² = 0.96, P < 0.05), P_n and biomass (r² = 0.74, P < 0.05) also suggested that the yield increase in the two cross-pollination treatments was generally owing to the higher photosynthetic rate and related photosynthetic traits.     

Effect of N supply on stalk quality in maize hybrids

The identification of maize nitrogen (N) response for stalk quality is valuable in stalk breeding improvement, stalk lodging resistance and for use in bioenergy. This study analyzed the effect of two N levels and estimated quantitative genetic parameters for stalk quality in summer maize in the north China plain (NCP). Thirty hybrids were sampled and tested from three to four geographic locations under high nitrogen (HN) (225 kg N ha⁻¹) and low nitrogen (LN) (0 kg N ha⁻¹) during 2006–2008. Compared to HN level, stalk crude protein (CP) was significantly reduced (22.06%) under LN level. Ether extract (EE), ash content (AC), in vitro dry matter digestion (IVDMD) and lignin content (LC) were lower under LN level. Cellulose content (CC), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were increased with a reduction in N, however N did not significantly affect EE, ADF and LC. An increase in NDF and ADF content under low vs. high N level was mainly attributed to a reduction in CC. ADF and NDF exhibited positive correlation and both showed a positive correlation with CC but a negative correlation with LC, IVDMD and CP. Negative correlations between IVDMD and CC, IVDMD and LC, and CP and CC were also detected. The interaction variance of genotype × year × location (σ²_GYL) for each N level, with the exception of σ²_GYL for CC under HN, was significant and most stalk quality traits were evaluated in different locations and years. The estimates of genetic variance (σ²_G) and heritability (h²) were greater under HN, with the exception of LC and EE. The interaction of genotype × nitrogen (σ²_GN) for CP was more important than σ²_G. The genotypic correlation coefficients (r_G) for performance in different stalk quality traits between HN and LN were significant. However, it was necessary to evaluate both HN and LN for IVDMD. For other stalk quality traits, breeding maize under HN levels may serve to develop hybrids well adapted to high and/or low N level. The response to N trend was similar between high oil and normal maize hybrids.     

耐旱丰产玉米育种的探讨

本文依据自己的育种实践,对耐旱丰产玉米育种的几个问题进行了讨论。认为玉米的耐旱性和丰产性在适当的选择环境下,运用相应的选择方法是可以有机结合在一起的;在育种实践中,田间相对萎蔫度、ASI、RI(修)是评价材料耐旱性的有效方法。发现目前广泛应用的骨干系中不乏玉米耐旱基因。认为水旱平行交替环境是选育耐旱、高配自交系的必要条件。并对耐旱丰产玉米杂交种的性状特点进行了研究。     

玉米缺素症状的研究

试验以东农248为材料,在苗期进行11种元素缺素处理,结果如下：1.形态变化：缺N、P、Ca、Mg、Fe、Zn、B元素,其地上部症状明显。缺N、P、K、Ca、Mg、Fe、Zn元素时,根量有显著差异;2.解剖结构：因缺素造成叶片脉间失绿和发黄部位是叶肉细胞内的叶绿体数目及内含物减少,液泡化明显的结果。干枯叶片的结构,表现细胞萎缩、排列不规整;3.生理指标：叶绿素a、b含量与光合速率在全部缺素处理中均低于对照。各缺素处理在形态、解剖和生理三者变化基本吻合。     

大豆DNA直接导入玉米自交系的研究

本文报导了大豆DNA直接导入自交授粉后的玉米自交系中的实验结果,通过1994～1998年的5代观察：玉米自交授粉后22 h导入外源DNA所产生的变异率最高,其变异性状较丰富,既具有供体性状的类型,也有新产生的类型,且多数性状在D₄代即能稳定,个别性状稳定较慢;实验表明：通过高蛋白材料DNA的导入可以改良受体的品质。