Genotypic differences in flag leaf area and their contribution to grain yield in wheat

Summary Flag leaf areas of the wheat variety Chinese Spring, six chromosome substitution lines of the variety Hope into Chinese Spring and their hybrids were measured by the planimeter method. Data on tiller number at ear emergence and ear number and grain yield at harvest were also obtained. Considerable variation existed in each of the characters investigated. The inheritance of flag leaf area showed some evidence of over dominance and non-allelic interaction while ear number was mainly under additive genetic control with partial dominance. Highly significant associations were found between flag leaf area, ear number and grain yield per plant. The importance of flag leaf area in yield determination was discussed in the light of the results obtained. It was concluded that despite the correlation between flag leaf area and grain yield, the major components of yield and grain yield itself, still offer the best guide for selection.     

江淮地区燕麦籽粒产量与农艺性状的相关性及通径分析

为了研究江淮地区燕麦籽粒生产的影响因素,选取了13个皮燕麦种质和7个裸燕麦种质,对其12个主要农艺性状和籽粒产量进行了相关性分析和通径分析。结果表明,12个农艺性状与皮燕麦籽粒产量的相关性大小依次为分蘖数>茎叶比>株高>茎粗>千粒重>穗长>旗叶宽>轮层数>小花数>穗鲜重>旗叶长>小穗数;对逐步回归分析筛选出的6个农艺性状和皮燕麦籽粒产量做通径分析,其直接效应依次为茎粗>分蘖数>茎叶比>穗长>株高>千粒重,株高和千粒重为负效应。农艺性状与裸燕麦籽粒产量相关性依次为小花数>旗叶长>小穗数>茎粗>穗长>分蘖数>穗鲜重>株高>轮层数>旗叶宽>茎叶比>千粒重;进行通径分析后,直接效应大小为穗鲜重>穗长>茎粗>小穗数>小花数>旗叶长>分蘖数,旗叶长和分蘖数为负效应。综合考虑,皮燕麦籽粒丰产的关键在于增加单株分蘖数;裸燕麦的生产过程中则要选择小穗性状优良、小花数适中的品种。     

Genetic analysis of some chlorophyll fluorescence and productivity parameters in barley (Hordeum vulgare)

Reciprocal crosses were made between five barley genotypes of diverse origin. Parents and 20 F₁S were grown in a greenhouse in a randomized block design with three replications. Each replication consisted of one pot containing three plants. Chlorophyll fluorescence activity of the penultimate leaf (below the flag leaf) of the main stem in each plant was measured at two stages of development (six-leaf stage and anthesis). At anthesis, and after measuring fluorescence parameters, a drought stress was applied. Yield components were measured at complete maturity. Statistical analysis for chlorophyll fluorescence parameters showed high genetic variability for the traits studied at both the six-leaf stage and anthesis, but most fluorescence parameters had decreased by anthesis. General and specific combining abilities of a diallel analysis were significant for most of the characters studied. General combining ability (GCA) values were usually more important than those of specific combining ability (SCA), showing the importance of additive genetic control for the fluorescence traits. Reciprocal effects were not significant for the fluorescence traits studied. A high genetic variability was also observed for yield components. Additive gene effects for plant weight, spike number, spike weight, number of grains per plant and 1000-grain weight were demonstrated. Potential photosynthetic activity (Rfd) at anthesis was positively correlated with plant weight, spike number per plant and 1000-grain weight.     

AL型小麦雄性不育细胞质效应的研究

对ＡＬ型小麦雄性不育系与同型保持系的性状差异的研究结果表明，不育系比保持系单株分蘖增加１．３５８个，抽穗提早０．５６４天，穗长增加０．６３３ｃｍ，分别达到５％或１％水平；但是，在叶片电导率、株高、单株穗数、总小穗数和旗叶长宽诸方面的差异均未达显著水平。ＡＬ型胞质败育花粉中有高度和轻度皱缩型及极少数的饱满圆型；而Ｔ型胞质的败育花粉几乎全属高度皱缩型。ＡＬ型与Ｔ型胞质的杂种间除穗长差异０．７１７ｃｍ，     

小麦冠层结构与产量及其构成因素的典范相关分析

选用２０个小麦品种（系）,采用典范相关分析方法,分析了小麦冠层结构与产量及其构成因素的相关性。结果表明,产量与其构成因素和植株特性呈显著相关,穗粒数和穗数对产量和单株产量的贡献均较大,干物重和株高对产量的贡献最大;叶长与产量呈显著相关,倒三叶长对产量的影响最大,对单株产量的影响３片叶相近;茎壁厚、节间长与单株产量呈显著相关。产量构成因素与各冠层结构特性均存在显著的典范相关。茎壁厚和节间长与茎粗均相关显著;在叶片特性中,除叶宽与披垂度相关不显著外,其余各组性状间均相关显著。     

冬小麦水旱品种间杂交主要性状的遗传分析

利用水地和旱地两种生态型的品种 ,采用 4× 4不完全双列杂交试验 ,对水旱品种间杂交主要性状的配合力和遗传表现进行了研究。结果表明 ,水地亲本的一般配合力效应对杂种后代主要性状的影响 ,除千粒重外 ,均达到显著或极显著水平 ;旱地亲本的一般配合力效应主要对株高、穗下节长、单株穗数、收获指数等与抗旱性有关的性状影响明显 ,且除株高和收获指数外 ,其余性状P1的方差均大于P2 的方差。说明水地亲本对杂种后代产量性状影响大 ,旱地亲本主要影响抗旱性状 ,水旱两种生态型杂交 ,实现了抗旱与丰产的有机结合。株高、穗下节长、穗粒数、单株产量、单株生物产量和收获指数以加性效应为主 ,而显性基因对单株穗数、千粒重、单穗重的影响较大。旱地小麦产量性状遗传力均较低 ,而株高、穗下节长、收获指数等与抗旱性有关的性状遗传力较高     

小麦旗叶性状与产量因素的相关与回归分析

以59个小麦品种(系)为试材,对旗叶性状与产量及产量因素作了相关与多元回归分析.结果表明,小麦旗叶的长、宽、叶面积、与茎杆的夹角、叶绿素含量与穗粒数、千粒重、穗粒重、产量等性状间的相关系数分别达显著或极显著水平,r=0.4851～0.7481.建立了旗叶性状与产量及产量因素的最优多元回归方程.     

11份玉米自交系单株产量等性状的配合力与遗传参数研究

旨在研究玉米自交系单株产量等性状的配合力、遗传力及反交效应,为玉米自交系的选育和杂交种的组配提供依据。以11份玉米自交系为试材,按Griffing Ⅲ完全双列杂交法组配110个组合,观测杂交种的单株产量、株高、穗位高、雄穗分支数、雄穗主轴长、抽丝期和开花期等7个性状的表型数据,并对上述性状的一般配合力、特殊配合力、广义遗传力、狭义遗传力和反交效应进行估算。供试材料除雄穗主轴长的特殊配合力差异不显著外,其余性状的一般配合力和特殊配合力差异均达到极显著水平。JZ3和JZ6两个自交系单株产量的一般配合力为极显著正值,两对组合JZ9×JZ2和JZ2×JZ9、JZ6×JZ3和JZ3×JZ6的单株产量具有最大的正向SCA效应值,分别为40.68 g和35.24 g。单株产量的反交效应差异极显著,部分自交系的反交效应方差较大。7个性状的广义遗传力从大到小依次为,雄穗分支数、株高、开花期、穗位高、抽丝期、单株产量和雄穗主轴长;狭义遗传力从大到小依次为,雄穗分支数、株高、穗位高、开花期、雄穗主轴长、抽丝期和单株产量。试验结果表明单株产量性状的显性遗传方差占比最大,狭义遗传力最小,易受环境条件的影响,对该性状的选择适宜在晚代进行;单株产量性状具有显著的反交效应,故部分自交系需严格控制正反交方式。     

小麦旗叶和芒的遗传及其与产量性状的相关性研究

通过对20个小麦品种（系）的研究表明,旗叶、芒对产量形成影响较大。旗叶、芒具有一定的遗传变异度,旗叶性状遗传力中等,芒遗传力较高。旗叶长、旗叶宽、旗叶面积、穗平均芒长均与穗粒重呈显著正相关;旗叶开张角、披垂度与穗粒重呈显著负相关。旗叶长与开张角、披垂度正相关,旗叶宽与开张角、披垂度负相关。育种中可将旗叶宽作为良好的株型性状加以选择。     

玉米自交系植株性状状与单株产量相关性研究

为研究玉米自交系主要植株性状与单株产量的相关性,选择代表性的父本、母本自交系采取随机区组设计,测定其主要植株性状和单株产量。结果表明,穗行数、行粒数、穗位高、雄穗分支数、节间长与单株产量均显著正相关,其中,穗行数与单株产量的相关性最强,相关系数达0.8824。株高与节间长、穗位高（r=0.7372）、穗行数和雄穗分支数显著正相关。穗长与百粒重极显著正相关(r=0.6631)。出籽率与穗行数、行粒数极显著正相关。在自交系选育过程中,穗行数、行粒数等穗部性状直接影响自交系的单株产量,但株高等同样是自交系选育的关键性状,自交系选育要兼顾穗部性状和植株性状,以获得株型适中兼大穗型的高产品种。     

三峡库区玉米地方品种配合力分析

为了明确三峡库区玉米地方品种育种潜势,以三峡库区常用的7个玉米自交系为测验种,采用NCⅡ设计,对三峡库区14个玉米地方品种的配合力以及主要性状遗传参数进行了分析。结果表明,‘文峰白玉米’、‘大寨玉米’、‘太阳河白玉米’在单株产量、穗长、穗粗、穗行数、行粒数、百粒重上具有较高的一般配合力。‘文峰白玉米’、‘大寨玉米’在改善株型、提高产量有更为突出的表现。不同性状SCA效应值变幅差异较大,其中单株产量变幅最大,为-25.48%~30.47%。所有性状中,亲本的基因加性效应均对F1性状形成起主导作用;穗长、穗粗、行数等7个性状广义遗传力和狭义遗传力均较高,可在早代进行选择;秃尖长、单株产量的广义遗传力较高,但狭义遗传力较低,不宜过早进行选择。     

密度与播期对晋西旱作玉米农艺性状及产量的影响

为了研究不同玉米品种在晋西旱作条件下的最佳栽培模式,采用3因素随机区组设计,对3个耐密型品种在4个种植密度和3个播期下的农艺性状及产量的数值差异进行比较研究。结果表明,密度对3个品种的最大叶面积指数、穗粒数、千粒重、产量的影响达显著或极显著水平,对株高、穗位高的影响不显著;播期对株高、穗位高、最大叶面积指数、穗粒数、千粒重、产量的影响达显著或极显著水平,主要农艺性状之间的交互作用共同影响并且决定了玉米产量。综合分析可知‘：先玉335’和‘大丰30’在67500株/hm²和5月中旬处理组合下产量最高,分别为13914.17kg/hm²、13487.67kg/hm²‘;福盛园55’在75000株/hm²和4月下旬处理组合下,产量最高为16114.37kg/hm²,本研究为3个玉米品种在本地区获得高产提供了一定的技术支撑。     

Correlation and Path Coefficient Analysis for Ear Characters in Triticale Under Mediterranean Climatic Conditions

In this study, the correlation and path coefficients between ear characters and grain yield per plant were determined in triticale under Mediterranean climatic conditions.
Weight of grains per ear and number of ears per plant were the most important direct components of yield. Characters like ear length and the number of spikelets per ear were not found to be the important component characters of grain yield. It could be concluded that among ear characters in triticale, the number of ears per plant and the weight of grains per ear are the most important yield contributing characters and these characters should get due consideration in future triticale breeding programmes.     

44个玉米杂交种产量与主要农艺性状的灰色关联度分析

为探明玉米品种的主要农艺性状对产量的影响程度,用灰色关联度的分析方法,对2013年44个玉米品种的主要农艺性状与产量进行关联分析。结果表明：在参试品种中穗粗(0.9874)、叶片数(0.9645)、穗长(0.9488)、株高(0.9465)、穗行数(0.9429)、百粒重(0.9244)、穗位(0.9088)、出籽率(0.8882)、秃尖(0.7381)等性状影响着玉米产量,其中,影响最大的主要性状是玉米的穗粗、叶片数和穗长,其次是株高和穗行数,千粒重对产量的影响相对居中,相比较之下,穗位、出籽率和秃尖对产量的影响最小。     

Genetic analysis of the response to day length in rice

Summary Inheritance of time-to-flowering, plant height, tiller number, spikelet number and flag leaf area was studied under day lengths of 10 and 14 hours in a diallel cross of six rice varieties. Early flowering was dominant to late in both environments but the varieties flowering early in one environment were late flowering in the other. Analysis of F₁ and F₂ data from the cross of Heenati-310 x IR-8 suggested a digenic control of early flowering in short days with complementary interaction. It is considered that while relatively few genes control time-to-flowering in rice a previous proposal that separate genes for time-to-flowering and photoperiod sensitivity exist is unnecessary on present evidence. Whereas culm length, tiller number and flag leaf area were increased by longer days, the number of spikelets per panicle was reduced. The length of the panicle was little affected by changing environment, and throughout certain characters and varieties, such as tiller number in I-geo-tze, were more stable than others. Varietal crosses of Heenati-310 x IR-8 and Tainan x MI-273(m) appeared to give high yield potential.     

小麦主要抗旱性状及杂交类型的遗传研究

对６个典型水、旱地小麦品种、三种杂交类型６个组合、５个性状Ｆ２世代的遗传研究表明：旱地条件下，单株产量，穗节长分别表现完全显性和超亲优势，且遗传传递力强，变异系数大，是Ｆ２重点选择性状；穗粒数也具有超亲优势，但遗传力弱，变异系数小，株高表现完全显性，遗传力较强，但变异系数甚小。此二性状应在Ｆ２后进行较大量地连续选择；旗叶长的３个遗传值均最小，应在高代再行选择。旱／旱、旱／水、水／水３种杂交类型中，     

Effects of an Early Application of Sulphur or Etephon as Foliar Spray on the Growth and Yield of Spring Barley in a Mediterranean Environment

Leaf area development, biomass production and yield of four spring barley varieties grown in a Mediterranean environment (southern Spain) in response to an early application of foliar sulphur or etephon have been studied. Both sulphur and etephon produced similar results compared to the control. Thus, whereas the maximum leaf area index on untreated plots was reached at the beginning of shooting, the growth of foliar area in the treated ones was extended until anthesis and its decline during maturity was similarly retarded. This led to a significant improvement in the biomass at anthesis (which was closely correlated with grain yield) as well as in the leaf area duration during grain filling. These effects were principally due to variations in the number of leaves per plant, caused by a higher tiller production in the treated plants and not by an increase in the number of leaves per tiller or by leaf size.
An application of sulphur or etephon at tillering increases grain yield by raising both the number of ears per plant and per plot, without modifying the number of grains per ear or 1000-grain weight. The similarity between the effects of sulphur and etephon may be due to the fact that sulphur absorbed by the leaves results in an increase in methyonine, the biological precursor or ethylene. The positive correlation between biomass at anthesis and number of ears over grain yield suggests that sink capacity and source activity are closely related and both simultaneously limited by the environment.     

Phenotypic and genotypic variation in seed production traits within a full-sib family of meadow fescue

Phenotypic and genotypic variation for seed yield and associated traits (heading date, plant height, number of fertile tillers, 1000‐seed weight, panicle length, seed weight per panicle, fertility, flag‐leaf length and flag‐leaf width) were studied in a full‐sib family of meadow fescue using replicated clonal trials at two locations in Norway. Genotypic variances were highly significant for all traits and genotype × location interactions were significant for heading date, number of fertile tillers and seed yield. Seed yield and other seed component traits exhibited the largest genotypic variations. Heading date showed large genotype × location interaction, probably because of the very diverse origin of the two parents of the full‐sib family. Path coefficient analysis showed that panicle fertility, measured as seed weight per unit length of panicles, was by far the most important component trait contributing to seed yield, followed by the number of fertile tillers, plant height and flag‐leaf width. Flag‐leaf width and plant height had sizeable indirect effects on seed yield via panicle fertility. This is the first time that the importance of the size of the flag leaf for seed yield in herbage grasses has been demonstrated.     

小麦不同绿色器官光合速率与碳同化酶活性及其基因型差异研究

比较了小麦不同基因型籽粒生长期旗叶与穗、茎、鞘等非叶绿色器官光合速率及光合碳同化酶活性的变化,结果表明, 存在显著的基因型差异。籽粒生长早期非叶器官净光合速率最大值低于旗叶，但后期的净光合速率下降幅度小于旗叶。各器官RuBPC活性和PEPC活性的变化均呈单峰曲线，RuBPC活性表现为旗叶>芒>叶鞘>穗下节间>颖片(护颖、外颖),其中芒的酶活性与叶片差异很小； PEPC活性表现为穗颖、叶鞘、穗下节间均明显高于旗叶。各基因型各非叶器官不同时期PEPC/RuBPC活性平均比值均明显高于旗叶, 后期非叶器官中PEPC活性甚至超过RuBPC活性。暗示在小麦生长后期的碳同化、特别是非叶器官的碳同化过程中，PEPC可能发挥着重要作用，后期非叶器官光合速率的相对稳定性可能与其较高的PEPC活性及活性下降缓慢有密切关系。在小麦品种改良过程中，不仅要重视叶片而且要重视非叶绿色器官光合性能、特别是PEPC活性的选择。     

水分胁迫对甜玉米主要农艺性状及产量的影响

在大棚内采用人工供水的方法,研究不同水分胁迫下甜玉米品种主要农艺性状与产量的关系。结果表明,轻度干旱胁迫下可用株高、茎粗、散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、千粒重等6个性状耐旱系数作为品种耐旱性鉴定的指标,而中度干旱胁迫下可用穗位叶面积、散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、出籽率、千粒重这6个性状耐旱系数预测品种产量的耐旱系数。在不同程度水分胁迫下,散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、千粒重等4个性状耐旱系数是不同品种耐旱性鉴定的重要指标,除此之外,株高、茎粗、穗位叶面积等决定植株形态的性状指标也对甜玉米耐旱性起一定作用。