水稻品种间性状优势强度关联性的初步研究

相关和通径分析表明,每株粒重的超亲优势与6个其它性状的超亲优势有密切正相关。其中,每株穗数和每穗实粒数两个性状的超亲优势对每株粒重超亲优势的直接影响最大;株高居中;每株茎数和每穗小穗数的超亲优势对每株粒重超亲优势的直接影响都比较小,它们主要是分别通过每株穗数和每穗实粒数的超亲优势起间接作用;每株秆重的超亲     

不同年份小麦产量与主要农艺性状通径分析

为了研究小麦产量的影响因素,本文对小麦产量的直接和间接影响因子进行分析。利用2005-2008年陕西省长武县中科院长武农业生态站小麦品种‘长武89134’为试验对象,分析其主要农艺性状之间对小麦产量的影响,对农艺性状和产量的关系进行相关分析和通径分析。各种农艺性状中每穗结实小穗数、千粒重和株高与小麦产量之间存在显著正相关关系,每穗粒数与产量之间达到显著的负相关关系,而地上部分总干重、籽粒干重和每穗小穗数与小麦产量的相关关系不显著。通径分析结果表明自变量每穗结实小穗数和株高对小麦产量的存在正向直接作用（r每穗结实小穗数=0.712**,r株高=0.848**,P<0.05）,而地上部总干重和每穗粒数则对产量存在着负向直接作用（r地上部分总干重=-0.792**,r每穗粒数=-0.784**,P<0.05）。‘长武89134’产量受到每穗结实小穗数、株高的正向作用和地上部总干重、每穗粒数的负向作用,因此需要主要针对这四种农艺性状进行筛选,在此基础上再并且协调好与其他农艺性状之间的关系,才能获得相对较高的产量。     

高粱16个数量性状的相关遗传力分析

运用多元遗传分析法分析了高粱１６个数量性状的相关遗传力参数。结果表明，多数性状间相关遗传力小于性状遗传力。当选择强度相等时，对一级枝梗数表型的选择可以明显提高二级枝梗数和穗粒数。对其他性状的间接选择相对效率都比性状的直接选择效率要低。相关遗传力通径分析表明，穗粒数表型对穗粒重的直接作用最大，其次为千粒重和二级枝梗数。各性状通过穗粒数都有最大的正向间接作用。因此，穗粒数对产量的贡献超过其他性状，是提     

广西早籼早熟杂交水稻产量与主要经济性状的分析

对2006～2010年广西早籼早熟杂交水稻区域试验49个品种(组合)的63组数据进行相关分析、通径分析和主成分分析,结果表明:有效穗,株高,穗长,总粒数,实粒数和千粒重与产量均呈极显著正相关;每穗实粒数对产量的贡献最大,而有效穗数通过每穗实粒数间接负作用较大.认为广西早籼稻品种(组合)高产育种应在保证一定有效穗数的基础上,主攻每穗实粒数,同时兼顾千粒重和结实率,协调好性状之间的关系.     

优质香稻黔香优302农艺性状与产量的相关性分析

对全香型杂交水稻新组合黔香优302的主要农艺性状及其在贵州省5个试验点的产量构成因素进行了分析。结果表明,黔香优302每穗实粒数、有效穗数和结实率变异系数较大,各农艺性状中对产量影响最大的产量因子是每穗实粒数、千粒重、有效穗数,其中有效穗数对产量的直接正向作用最大,有效穗数与每穗粒数之间存在一定的负相关。在栽培技术上,应主攻有效穗数、每穗总粒数与结实率,并协调有效穗数与每穗实粒数之间的关系。     

杂交水稻经济性状的相关分析与通径分析

本文研究了11个广东省主推杂交水稻组合主要经济性状间的相互关系及其对产量的通径作用.结果表明:单株产量与每穗实粒数和生物产量达到显著和极显著正相关;而与千粒重达到极显著负相关.每穗实粒数对单株粒重的直接贡献最大,其次是生物产量、千粒重;株高、每株穗数的直接效应为负.广东省的杂交水稻育种和栽培目标是:株高适中,大穗粒多,粒小,分蘖适中.     

旱地不同玉米品种穗部性状与产量关系的综合分析

对45个玉米杂交种的8个穗部性状指标与产量之间的关系进行综合分析,结果表明:单株粒重和千粒重与产量之间呈显著正相关。各穗部性状对产量的直接贡献依次为:单株粒重、行粒数、穗长、千粒重、秃尖长、出子率、穗行数、穗粗。单株粒重对产量的直接效应最大。行粒数在直接对产量负向效应中表现最高,行粒数、千粒重、穗行数和穗粗都是通过单株粒重间接对产量产生影响。聚类分析结果表明,第3类单株粒重较高,其他穗部性状之间较协调,产量表现最高。综上所述,旱地条件下,选择高产玉米品种应该首先关注品种的单株生产能力,在此基础上兼顾行粒数、千粒重、穗行数和穗粗等性状。     

作物产量构成因素与产量通径分析方法的商榷

作物产量构成因素与产量通径分析方法的商榷张存良，殷毓芬，吴祥云（山东省农科院作物所济南２５０１００）作物产量的高低（以小麦为例）受三因素直接影响，由亩穗数、穗粒数和千粒重三者决定。三因素虽又受其它性状影响，而其它性状也只能通过三因素间接作用于产量，不...     

四川中籼中熟杂交水稻产量与主要经济性状的分析

通过对1996—2005年四川省中籼中熟杂交水稻区试试验86个组合的116组数据进行相关和通径分析,结果表明,每穗总粒数与每穗实粒数,结实率与产量均成极显著正相关,有效穗对产量的贡献最大,但由于有效穗数通过穗粒数的间接副作用较大,所以有效穗数太大对提高产量反而不利。笔者认为,四川中籼中熟杂交水稻高产应在保证一定穗数的基础上,主攻每穗实粒数,同时兼顾提高千粒重,协调好性状之间的关系。其单产9.0t/hm2的产量构成因素是：有效穗数265~270万/hm2,每穗总粒数180~200粒,结实率大于84%,千粒重27~29g。     

不同类型杂交早稻农艺性状的遗传分析

采用6个杂交稻三系不育系和10个杂交早稻父本品种,通过不完全双列杂交配置了60个杂交早稻组合。分析了在相同栽培环境条件下三系杂交早稻亲本及其所配置的杂交早稻组合的12个农艺性状的遗传规律。结果表明：12个农艺性状的遗传以加性效应为主,各性状的狭义遗传力大小顺序依次为千粒重>株高>穗长>穗实粒数>结实率>穗总粒数>生育期>理论产量>实际产量>有效穗>成穗率>最高苗;除穗长外,其余性状受父本的影响较大;理论产量与结实率、穗实粒数、株高、成穗率及有效穗呈正相关,可通过这几个性状对产量进行间接选择;穗实粒数是杂交早稻选择指数中最重要的选择性状。     

玉米理想株型经济性状的遗传相关与通径分析

利用逐步回归、遗传相关、通径分析的统计方法,研究玉米理想株型杂交种,在一定的生态和栽培条件下,雄穗分枝,果穗长、穗行数、千粒重、出籽率对单株粒重的直接和间接效应.结果表明:行粒数、千粒重的直接作用与果穗长通过行粒数的间接作用,对单株粒重的相对决定程度都较高,在影响单株粒重诸因素中占主导地位.初步认为以这三个性状作为选择指标,直接选择,并协调好千粒重与行粒数的关系,可望选出单株籽粒产量较高的杂交种.     

普×爆F3家系穗粒性状及其与膨化倍数的相关分析

在春播和夏播两种环境条件下,对一个普通与爆裂玉米自交系杂交组合的259个F3家系的穗粒性状及其与膨化倍数的相关分析结果表明：F3代分离出优于爆裂亲本穗粒性状的家系较多;穗粒性状是由微效多基因控制的数量性状;百粒重、穗粒重对膨化倍数直接或间接作用为较大负效应,行粒数、轴粗、穗长对膨化倍数的直接作用为正效应,其它性状通过行粒数和穗长对膨化倍数的间接作用多为正效应。因此,可以直接对穗长和行粒数进行正向选择,提高普×爆后代选系的产量。     

玉米杂交组合主要农艺性状与产量的多重分析

为了研究玉米农艺性状对产量的影响大小,筛选出综合表现优良的玉米品种,为高产育种提供理论依据。以本课题组选育的14 份玉米杂交组合为试验材料,对其穗长、穗粗、轴粗等9 个农艺性状进行测定,并采用变异性分析、相关性分析、通径分析和主成分分析进行比较和评价。结果表明,参试材料的9 个农艺性状的变异系数在2.19%~58.72%之间;相关分析表明,行粒数与产量呈极显著正相关(r=0.450),秃尖长与产量间呈显著负相关(r=-0.336);通径分析表明,穗粗、行粒数和出籽率对产量的直接作用为正值,穗长、轴粗、秃尖长、穗行数和千粒重对产量的直接作用为负值;主成分分析表明,对产量贡献大小排序为秃尖长因子>行粒数因子>穗行数因子>穗粗因子。因此,在玉米育种材料筛选时,应重视行粒数多、果穗较粗和秃尖小的育种材料,同时要关注千粒重,并注意性状间的协调发展,以便充分挖掘种质资源潜力,选育出优异的玉米品种。     

Sequential path analysis of grain yield and its components in maize

The efficiency of a breeding programme depends mainly on the direction and magnitude of the association between yield and its components and also the relative importance of each factor involved in contributing to grain yield. The purpose of this research is to describe the application of causal path analysis to grain yield in maize (Zea mays L.) to take into account the sequential development of yield components. Causal-admissible path analysis was performed assuming unidirectional causal relationships among yield components of eight maize populations. Sequential path analysis of the five yield components studied revealed that ears per plant had the highest direct effect on grain yield. However, the indirect effects of component traits via number of grains per ear was maximum. It was concluded that the number of kernels per ear, prolificacy, and grain size serve as potential characters in breeding for superior lines for grain yield in maize.     

Plant character correlations and path analysis of pod yield in okra (Abelmoschus esculentus)

Summary Genotypic, phenotypic and environmental correlation coefficients were calculated for fifteen characters during two growing seasons. Correlation coefficients varie between seasons. Edible pod weight, edible pod length, edible pod width, number of seeds per plant, weight of 100 seeds, length of mature pods and number of branches per plant showed significant genotypic correlation with pod yield per plant; only number of branches per plant, edible pod length and weight of 100 seeds were phenotypically correlated with pod yield. Environmental correlation coefficients were generally low but edible pod length, final plant height and edible pod weight showed significant environmental correlation with pod yield during the two seasons.The genotypic correlation coefficients of selected eight characters with pod yield were partitioned into direct and indirect causes. In the early seasons, edible pod weight had the largest positive direct effect on pod yield with its largest indirect effect through reduction in edible pod width. Edible pod width which was highly correlated with pod yield had a negative direct effect on pod yield. In the late season, edible pod weight had the largest direct effect on pod yield, with large indirect effects through reduction in number of days to flowering and number of pods per plant. Number of days to flowering had a large direct effect on pod yield with its largest indirect effect through reduction in edible pod weight. The residual factors during the two seasons were negative. The study indicated that only number of branches per plant, edible pod length and weight of 100 seeds would be useful for indirect selection for pod yield. The path analysis indicated that edible pod weight was the most reliable and effective character to select for when high yield is the objective.     

播种期和种植密度对小麦新品种豫农202产量构成的影响

合理的播种期和种植密度有助于挖掘小麦品种的产量潜力。利用裂区试验研究了播种期和种植密度对小麦新品种豫农202产量及其构成因素的影响。结果表明：播种期对小麦新品种豫农202的产量及其构成因素影响较小,除对穗数的影响达显著水平外,其它均不显著。种植密度则影响较大,除对千粒重的影响不显著外,其它均达到显著或极显著水平,特别是对穗数和穗粒数影响的显著程度非常高。在不同的播种期下各种植密度间产量差异较大,但产量构成因素差异较小。在不同播种期和种植密度下,穗数对产量的直接影响较大,其次是穗粒数,千粒重的直接影响很小。该品种的适宜播种期应该在10月8日至10月25日,早播情况下选择120万/ hm2基本苗较合适,中晚播情况下选择240万/ hm2。     

冬小麦子粒品质性状多目标间接选择数学模型初探

利用56个冬小麦品种(系),采用双重逐步回归的方法,建立了冬小麦子粒品质性状多目标间接选择数学模型.结果表明.适当增加株高和单株穗数,可同时提高单株子粒蛋白质产量与含量及干面筋含量;而增加单株子粒产量可以提高单株子粒蛋白质产量,但降低子粒蛋白质含量和干面筋含量;千粒重每增加1.0g,沉淀值减少0.07791ml;湿面筋含量随株高增加而增高,随结实小穗数增加而降低.     

Why SR52 is such a great maize hybrid? II. Heritability,correlation and path-coefficient analyses

Although exceptional heterosis for yield in the world’s first commercial single cross maize (Zea mays L.) hybrid SR52 has been confirmed, the role of secondary traits hasn’t been established. Objectives of this study were to establish relationship between grain yield and secondary traits, while assessing heritability and genotypic variation in SR52’s segregating populations. Knowledge on associations between yield and secondary traits would be crucial in extracting productive inbred lines from the population. Traits were subjected to correlation and path-coefficient analyses. Path analysis model accounted for over 70% of variation (R²) in all populations. Consistently high positive correlations with grain yield were observed for ear length and number of kernel rows on ear. Ear girth (0.19), and number of kernels per row (0.48) showed high direct effects on yield in the F₂ population and the trend was consistent in the backcrosses. Positive indirect effects of most traits on grain yield were negligible with the exception of kernel per row via total number of kernels on ear, which was above 0.40 in the F₂ and BCP1. Ear length can be exploited for indirect selection for yield in SR52’s segregating generations. 100-kernel weight and number of kernel rows on ear can, to a lesser extent, be targeted in selecting for grain yield. High to medium phenotypic variability in segregating generations of SR52 for traits such as ear length, number kernel rows on ear and grain yield should give impetus to selection of productive inbred lines from SR52 hybrid because of presence of diversity in the gene pool.     

糯玉米杂交种主要农艺性状间的相关及通径分析

对鲜食糯玉米的10 个主要农艺性状与小区鲜穗产量进行了相关和通径分析。结果表明,性状间株高与穗位高(r=0.6288**)、株高与双穗率(r=0.5779**)、株高与穗长(r=0.5069**)、株高与穗粗(r=0.4878**)、双穗率与行粒数(r=0.4877**)、行粒数与穗粗(r=0.4686**)、秃尖长与穗行数(r=0.4355**)之间均呈极显著正相关;而秃尖长与双穗率(r=-0.4356**)、秃尖长与行粒数(r=-0.5350**)之间呈极显著负相关。对鲜穗产量作用最大的是穗行数(r=0.5314**、P=0.7480),其次分别为双穗率(r=0.4724**、P=0.4177),行粒数(r=0.4127*、P=0.2317),百粒质量(r=0.3637*、P=0.2159)。为获得高产糯玉米品种,应注重增加穗行数、行粒数、提高双穗率和百粒质量,同时协调好各性状间的关系,控制好株高、穗位高及秃尖长度等性状。     

Genetic variation,heritability and path-analysis in landraces of bread wheat from southwestern Iran

Summary Nine pure lines of bread wheat collected from landraces of southwestern Iran and one local Iranian cultivar from the same area were used to estimate genetic variation and heritability for 12 developmental and yield component characters. Path-analysis was used to partition the genetic correlations between some of the characters into direct and indirect effects. Mean values for these lines were also compared with those of five improved cultivars from Iran and California. The goal of the experiment is to breed improved landraces and/or modern cultivars for areas of low input agriculture in southern California, southwestern Iran, and regions with similar environmental and agronomic conditions.Moderate genetic variation was displayed by the number of effective heads per plant, number of grains per head, and grain weight in the landrace genotypes. The heritability estimates ranged from 43 to 97%. Expected genetic advance with selection of the highest 5%, expressed as percent of the mean, was around 20% for number of heads per plant, number of grains per head, and 1000-grain weight.Days to booting, to heading, and to anthesis were positively correlated but none of them were significantly associated with days to maturity. Plant height had a negative genetic correlation with number of grains per head, 1000-grain weight, grain yield, and harvest index. The genetic correlation between number of heads per plant and number of grains per head, 1000-grain weight, and harvest index was also significantly negative. Harvest index had a negative genetic correlation with days to booting, to maturity, plant height, number of heads per plant, and straw yield and a positive correlation with number of grains per head, 1000-grain weight, and grain yield.Days to maturity, plant height, number of heads per plant, number of grains per head, 1000-grain weight, and harvest index each had a positive direct effect on grain yield. The first two characters exhibited the highest and lowest direct effects, respectively. The positive direct effects of days to maturity, plant height, and number of heads per plant, however, were partially or completely counter-balanced by their strong negative indirect effects through number of grains per head, 1000-grain weight, and harvest index. Pathanalysis indicated that late and tall landrace genotypes tend to produce more heads per plant, but with fewer number of grains per head, smaller grains, and lower harvest index.Comparisons between the local lines and the improved cultivars revealed that, in general, the former were much taller and produced a larger number of non-effective tillers. Mean number of grains per head, grain weight, harvest index, and grain yield of local lines were smaller than those of improved cultivars.Our observations indicate that the landraces could be improved by selecting for shorter genotypes with smaller numbers of tillers per plant, but with larger numbers of grains per head and heavier grains.