不同种质玉米自交系穗粒性状特征分析

玉米穗粒性状是决定产量的重要因素。为了明确不同种质玉米自交系的穗粒性状特征及对种质创新和高产育种提供参考,本研究以211个不同种质玉米自交系为材料,对穗长、穗粗、穗行数、行粒数、粒长、粒宽、粒厚、百粒重和籽粒密度9个穗粒性状进行统计和系统聚类分析。结果表明,供试玉米自交系间各穗粒性状均存在显著差异,除籽粒密度外均存在较大变异系数;采用欧氏距离法进行聚类分析将供试玉米自交系分为7个类群,穗长、穗粗、行粒数和粒长均以类群G6最高,粒宽和百粒重均以类群G5最高;郑单958和先玉335两大杂交种的4个亲本自交系各自所属类群相比,4个类群分别有单个或多个自交系多个性状较优,可以为育种工作中穗粒性状的改良提供依据。     

拔节期干旱对春玉米产量性状及抗旱性的影响

在干旱区大田条件下,选用当前生产上主推密植型玉米品种,在拔节期不同干旱胁迫度下,对其产量性状及抗旱性进行研究,结果表明,不同旱胁迫度下百粒重与产量均呈极显著正相关;随干旱胁迫程度增加,穗粒数对产量所起的直接效应明显增加,而穗粒数则与行粒数呈极显著正相关,所以百粒重是决定产量的首要因子,其次是穗粒数,而行粒数则决定了穗粒数。品种抗旱性分析结果表明,大丰30丰产性较好,而抗旱性一般;富友968抗旱性最好,而丰产性较差;潞玉36则抗旱性和丰产性均较差。     

土壤含水量对玉米产量因素的影响研究

在旱作条件下研究了不同玉米品种的穗长、穗粗,行粒数,百粒重等产量因素和亩保苗株数、灌浆期土壤含水量等环境因素对产量的影响。结果表明：穗粗对产量有极显著的正相关和正向的直接效应,百粒重和穗长对产量呈微弱的正相关,行粒数对产量有微弱的负相关。土壤含水量与产量有较高的负相关和负向的直接效应,株高、功能叶数、亩保苗与产量有较低的正相关。灌浆期比较抗旱品种是丰禾7号、绥玉7号和丰禾332品系;先玉335表现中度抗旱,龙单13、四单19表现出抗旱性较差。     

常用玉米自交系抗旱性及抗旱性鉴定指标研究

采用人工水分胁迫处理,通过植物生理学方法,对10个常用玉米自交系进行了抗旱性研究。结果表明,不同玉米自交系存在明显差异,沈136、齐319、丹598和沈137耐旱性较好,可以作为玉米耐旱育种的基础材料。干旱胁迫下,玉米植株叶片相对含水量、丙二醛含量、电导率和ASI与玉米子粒产量极显著相关,能够比较准确地评价玉米自交系抗旱性的强弱,和抗旱系数、抗旱指数一样可以作为玉米育种耐旱自交系筛选的鉴定指标。     

PEG模拟干旱胁迫下玉米胚芽鞘长与其抗旱性的关系分析

以6份抗旱性不同的玉米自交系为试材,用不同浓度的PEG-6000(polyethylene glycol,PEG)渗透溶液进行模拟干旱胁迫处理,分析玉米萌芽期中胚轴长、胚芽鞘长及苗长的变化,并将其与田间干旱胁迫处理下相应玉米自交系产量及产量相关性状的抗旱指数进行相关分析,以期揭示萌芽期玉米幼苗相关性状与其抗旱性的关系。结果表明:(1)萌芽期随着PEG浓度增加,玉米自交系胚芽鞘长、中胚轴长及苗长都呈下降趋势,其中苗长降低幅度最大,平均降幅为14%,中胚轴长次之,平均降幅为11%;(2)方差分析表明,不同玉米自交系幼苗的中胚轴长、胚芽鞘长在自交系间及PEG浓度间差异极显著,苗长在PEG浓度间差异极显著;(3)花期田间干旱胁迫下,各玉米自交系的千粒重、穗粒数及产量较正常灌溉明显下降,且其平均降幅分别为8%、14%、13%;(4)通过玉米田间产量及产量相关性状抗旱指数与萌芽期各性状相关性分析表明,中胚轴长与千粒重、穗粒数及产量的抗旱指数呈显著或极显著正相关。胚芽鞘长与千粒重、穗粒数及产量的抗旱指数呈极显著正相关,而在5%的PEG-6000渗透溶液模拟干旱胁迫下,胚芽鞘长与千粒重抗旱指数相关系数最高为0.832。因此,胚芽鞘较长的自交系其抗旱性较强,胚芽鞘长度可作为玉米早期抗旱性筛选的重要指标。     

玉米自交系表型性状与产量的灰色关联分析

以257份玉米自交系为材料,采用灰色关联分析方法,对影响玉米自交系产量(单株粒重)的主要表型性状进行研究。结果表明:关联序排在前三位的是全生育期、散粉期与吐丝期,生育期是影响玉米自交系单株粒重最重要的因素,其他性状与单株粒重的密切程度依次减小;与产量相关的主要性状中,关联序排在前三位的是穗位、穗长、百粒重;总体排序为全生育期>散粉期>吐丝期>穗位>穗长>百粒重>全株叶数>株高>穗位叶面积>穗粗>出苗期>行粒数>行数;高产玉米自交系选育目标:尽量延长生育期,提高穗长及百粒重,其他性状适中,协调相关因素,提高产量。本试验利用大量有代表性的玉米自交系,明确了主要农艺性状对产量的贡献,为选育高产玉米自交系提供了理论参考依据。     

灰色系统理论在玉米育种上的综合应用

利用灰色系统理论,分析了８个影响玉米单交种产量相关因素,结果表明,产量因素与产量的关系依次为行粒数＞百粒重＞穗长＞株高＞穗行数＞穗位高＞穗粗＞播种至抽丝天数。研究了１８个玉米杂交组合的优劣,将１８个玉米杂交组合分为３类。同时对自交系进行了分析,表明综３１和Ｐ１６７是较好的自交系。初步探讨了灰色系统理论在玉米育种上的综合应用。     

攀西地区玉米地方品种萌芽期抗旱性研究

为进一步利用攀西地区玉米地方品种进行抗旱育种提供理论依据,采用聚乙二醇-6000模拟水分胁迫,通过种子发芽试验,以萌芽抗旱指数、活力抗旱指数、相对发芽率、贮藏物质相对转运率和百粒重为鉴定指标,对66份攀西地区玉米地方品种萌芽期抗旱性进行鉴定。结果表明,玉米种子萌芽期抗旱指标应以萌芽抗旱指数为主,但还要以其他指标为辅,才能全面评价品种的抗旱性。66份地方品种对水分胁迫的反应有显著差异,其中18份材料表现较强的抗旱性,5份资源在多个指标上都表现极强的抗旱性。     

灰以系统理论在玉米育种上的综合应用

利用灰色系统理论，分析了８个影响玉米单交种产量相关因素，结果表明，产量因素与产量的关系依次为粒数〉百粒重〉穗长〉株高〉穗行数〉穗位高〉穗粗〉播种至抽丝天数。研究了１８个玉米杂交组合的优劣，将１８个玉米杂交组合为分为３类。同时对自交系进行了分析，表明综３１和Ｐ１６７是较好的自交系。初步探讨了灰色系统理论在玉米育种上的综合应用。     

玉米品种辽单506丰产稳产性及产量构成因素分析

为了全面地了解玉米品种辽单506的生产特性,以2015—2017年玉米品种辽单506区域示范测产结果为资料,通过产量、变异系数和产量构成因素分别对辽单506的高产稳产性及其产量构成因素进行分析,结果表明:辽单506的丰产性、稳定性、适应性优于对照品种,是一个较为理想的高产玉米新品种。辽单506产量构成因素与产量相关程度依次为:穗数(0.419 3)、百粒重(0.106 1)、穗粒数(-0.138 9);对产量的直接影响依次为:穗数(0.451 9)、百粒重(0.120 2)、穗粒数(-0.156 2)。辽单506的高产高效栽培技术措施为:做好苗期管理,保证有效种植密度;酌情追施花粒肥,增加百粒重,以促进品种产量潜力的发挥。     

非生物胁迫对玉米杂交种及其亲本自交系产量性状的影响

以抗逆性较强玉米杂交种郑单958及其亲本(郑58、昌7-2)和抗逆性较差的杂交种陕单902及其亲本(K22、K12)为材料, 在不同种植密度(45 000株 hm^-2和75 000株 hm^-2)、施氮量(112.5 kg hm^-2和337.5 kg hm^-2)和灌水量(正常灌水和前期干旱控水)条件下, 分析了2个杂交种及其亲本产量及相关生理特性的变化规律。结果表明, 在非生物胁迫条件下(高密度、低氮和前期干旱控水), 与陕单902相比, 品种郑单958叶面积指数、SPAD值、花后干物质积累量和产量的中亲优势值分别增加18%、9%、28%和22%; 与陕单902亲本(K22、K12)比, 郑单958亲本(郑58、昌7-2)叶面积指数、SPAD值、花后干物质积累量和产量的中亲值分别增加45%、36%、51%和45%; 郑单958产量的中亲值和中亲优势显著高于陕单902, 且中亲值增幅高于杂种优势值。玉米杂交种郑单958较陕单902增产的同时, 增强了对非生物逆境适应的能力。玉米杂交种的抗逆性来自亲本自交系。玉米杂交种抗逆性强在于增强了花后叶片光合能力(较高的LAI和SPAD值), 促进了花后干物质积累。     

玉米自交系叶片水分利用效率差异性及其生理变化

为选育抗旱性强、耗水少、水分利用效率高的品种.以22个玉米自交系为材料,采取正常灌溉和适度水分胁迫处理,对自交系叶片水分利用效率(WUE)、光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)、相对叶绿素值( SPAD)和荧光动力学参数进行研究.结果表明,不同自交系WUE差异显著,而且对水分的敏...     

玉米自交系生理指标与抗旱性及复水恢复能力的关系研究

【研究目的】为了评价不同玉米自交系的抗旱性，探究生理指标与抗旱性、恢复能力和综合抗旱能力之间的关系。【方法】本研究以19份自交系为材料，采用盆栽称重控水法对苗期玉米进行中度旱胁迫及复水，测定生物量、叶绿素含量、类胡萝卜素含量、Fv/Fm、脯氨酸含量和抗氧化酶活性对干旱和复水的响应。【结果】分析发现自交系‘郑8713’、‘郑63’和‘昌7-2’的抗旱性、恢复能力和综合抗旱能力均较强，自交系‘郑C112’、‘郑718’和‘郑6722’虽然抗旱性较弱，但是恢复能力和综合抗旱能力较强，自交系‘郑3733’、‘郑E846’和‘郑36’恢复能力较弱，但是抗旱能力和综合抗旱能力很强；同时发现类胡萝卜素与抗旱性之间呈现显著的相关性(P=0.503*)，POD抗氧化酶与复水后的恢复能力之间关系显著(P=0.421*)，Fv/Fm与综合抗旱性之间呈显著的相关性(P=-0.456*)，叶绿素含量与抗旱性(P=0.468*)和复水后的恢复能力(P=0.407*)之间均呈现显著的相关性。【结论】以上结果为培育抗旱型品种提供优良的种质资源，同时为玉米抗旱性、恢复能力及综合抗旱能力的筛选与鉴定提供一定的指导意义。     

玉米优良自交系埃1278C、埃1278C—2与海7—1的选育及其抗病性鉴定

本研究自1969年开始,应用一环系和二环系选育方法选育玉米自交系.到1973年先后育成了两个白粒马齿型和一个黄色硬粒型优良自交系.这三个自交系产量高,配合力好,综合性状优良.根据在室内和田间抗病性鉴定的结果,它们的抗大小斑病性类似或优于抗病系330,525,C103,MO17;埃1278C—2的抗小斑病性表现尤为突出.本文还就选育抗病系的方法和早代测定配合力的效果进行了讨论.     

Development of drought‐tolerant breeding lines derived from Helianthus annuus × H. argophyllus interspecific crosses

Helianthus argophyllus is a wild species known as “silver sunflower”, which possesses several traits, including morphological traits that increase drought tolerance. Therefore, introgressions between chosen cultivated lines and two H. argophyllus accessions were made, and segregating generations were established. Important agronomic traits including single heading, high pollen fertility, silver canopy (indicating more cuticular wax), and content of cuticular waxes and oil were selected over six segregating generations. The resulting F₆ lines showed introgression of water saving traits, as they had lower excise leaf water loss, with comparable yield to standard checks. However, these F₆ lines were late maturing and showed poor flowering synchronization between the cultivated and introgressed lines. Introgressed line “D‐22” was particularly promising as a breeding line, with superior agronomic and drought resistance traits. This line had the potential to be used as an inbred parental line for introgression of drought resistance traits into elite sunflower germplasm. Combining ability analysis of the introgressed lines further showed their potential for heterosis breeding or to be used as parental lines in breeding programme.     

Traits related to drought resistance in common bean

Common bean (Phaseolus vulgaris L.) is grown in regions where water deficits during reproductive development significantly reduce yield. The purpose of this study was to evaluate the association of specific phenological and physiological traits with drought resistance in common bean. Five genotypes were grown under and near a rain shelter in 1988, and an additional 16 progeny lines were included in 1990. Drought stress determined by the drought intensity index was severe (0.78) in 1988 and more moderate (0.63) in 1990. Water stress reduced the expression of most traits with the exception of days to flower and leaf moisture retention capacity. Seed yield among genotypes was reduced from 22 to 71% due to drought. Yield under stress was correlated with yield under nonstress in 1990 and negatively correlated with the drought susceptibility index in 1988. Yield components which exhibited the largest differential genotypic responses to stress were pod and seed number, whereas seed size was more stable. Genotypic variation was detected in all the partitioning indexes, chiefly harvest index and relative sink strength, and the heritability estimates for these traits were high. The limited genetic variability observed among water relations traits and their role in water conservation would restrict their potential use in the selection for drought resistance in common bean. The differential correlations between phenological, biomass and partitioning traits and the indexes for yield and drought susceptibility would suggest that the most effective approach in breeding for drought resistance in common bean would be based first on selection for high geometric yield followed by selection among the high-yielding individuals for low to moderate levels of the drought susceptibility index. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic variation in drought tolerance at seedling stage and grain yield in low rainfall environments in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Genetic architecture of seedling drought tolerance is complex and needs to be better understood. To address this challenge, we developed a protocol to identify the most promising drought-tolerant genotypes at the seedling stage in winter wheat. A population of 146 recombinant inbred lines (F₉) derived from a cross between wheat cultivars, ‘Harry’ (seedling drought tolerant) and ‘Wesley’ (seedling drought susceptible) were used in this study. All genotypes were sown in three replications in a randomized complete block design under controlled conditions in a greenhouse. Seven traits were scored and grouped into tolerance traits; days to wilting, leaf wilting, and stay green and survival traits; days to regrowth, regrowth, drought survival rate, and recovery after irrigation. Three selection indices were calculated (1) tolerance index, (2) survival index, and (3) drought tolerance index (DTI). The same set of genotypes were also tested for grain yield in two low rainfall environments for two seasons. High genetic variation was found among all genotypes for all seedling traits scored in this study. Correlations between tolerance and survival traits were weak or did not exist. Heritability estimates ranged from 0.53 to 0.88. DTI had significant phenotypic and genotypic correlations with all seedling traits. Genotypes were identified with a high drought tolerance at the seedling stage combined with high grain yield in low rainfall. Breeding for tolerance and survival traits should be taken into account for improving winter wheat drought tolerance at seedling stage. The selected genotypes can be used for to further improve drought tolerance in high yielding wheat for Nebraska.     

北方粳稻分子育种研究进展

本文介绍了北方粳稻分子育种课题的研究情况和所取得的研究成果。目前主要进行两方面的研究，一方面为特异基因型的鉴定：主要有筛选鉴定出抗旱性材料86份，苗期抗寒性材料40份，后期抗寒性材料629份，抗稻瘟病材料28份，对筛选出的抗旱性材料进行了第二轮聚合杂交，共配组合171个。另一方面是关于遗传与生理基础研究，对穗部性状、粒形、产量和品质以及它们之间的关系进行了深入的研究。另外本文对北方粳稻分子育种材料构建过程中存在的问题进行了综合讨论，并讨论北方粳稻分子育种今后的发展方向。     

转AtHDG11基因玉米的获得及抗旱性鉴定

培育抗除草剂和抗旱的转基因玉米种质,通过超声波辅助农杆菌介导花粉非组培法将拟南芥抗旱基因At HDG11导入玉米自交系昌7-2中,获得转基因植株。通过逐代除草剂筛选、分子检测对获得的转基因植株进行检测,获得5株转基因株系。在此基础上,以非转基因自交系昌7-2为对照,对5个转基因株系进行抗旱性鉴测;对苗期和十叶期玉米植株进行干旱胁迫处理,测定转基因植株生理活性物质和光合参数。结果表明,在干旱胁迫条件下,转基因玉米叶片的Pro含量高于非转基因玉米,MDA含量低于非转基因玉米;不论在正常生长条件下还是干旱条件下,转基因株系的光合速率和水分利用率都明显高于对照植株;而转基因株系的蒸腾速率和气孔导度则明显低于对照植株。综合室内与田间的抗旱检测结果表明,超声波辅助农杆菌介导花粉的非组培转基因方法在玉米上是可行的。将拟南芥HDG11基因导入玉米,同样可以有效地提高玉米的抗旱性,为玉米的抗旱育种提供新的种质资源和新的转基因方法。