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1.
M. Hühn 《Journal of Agronomy and Crop Science》1990,164(4):271-281
The harvest index Z is defined, for example for cereals, as the ratio between grain yield X and biological yield Y: Z = X/Y. For many purposes the variance of Z is of major interest. In this paper several approximations for this variance are derived and their accuracy was investigated. These explicit formulae depend on some characteristics (means, variances or coefficients of variation, covariances or correlations) of the component variables grain yield X and biological yield Y. It is shown that for most practical applications the approximation v2 z = v2 x + v2 y - 2rvx vy provides a sufficient accuracy for numerical calculations (vx vy and vz are the coefficients of variation for grain yield X, biological yield Y and harvest index Z and r denotes the correlation coefficient between X and Y). Some conclusions on the relations between vx , vy and vz are derived.
Finally, all the theoretical investigations and results are demonstrated and applied to a numerical example of winter-rapeseed data. 相似文献
Finally, all the theoretical investigations and results are demonstrated and applied to a numerical example of winter-rapeseed data. 相似文献
2.
M. Hühn 《Journal of Agronomy and Crop Science》1990,165(2-3):86-93
The harvest index Z is defined, for example for cereals, as the ratio between grain yield X and total yield Y: Z = X/Y. For individual measurements xi of X and yi of Y the individual harvest index is calculated by zi = xi /yi . These individual measurements i are based on N different experimental units (single plants, random samples from plots or total plots).
Mean harvest indices are commonly calculated either by or by where the means of X, Y and Z are denoted by , and respectively.
Both approaches are, in general, different. But, in this paper it is shown that for most situations which may occur in the field of practical applications in agronomy and plant breeding both procedures will lead to nearly identical results. Only in some special situations the two results differ significantly. These conditions are investigated and explicitly given.
Some explicit formulae (approximations) for the calculation of mean harvest indices are derived and discussed.
Finally, all the theoretical investigations and results are demonstrated and applied to a numerical example of winter-rapeseed data. 相似文献
Mean harvest indices are commonly calculated either by or by where the means of X, Y and Z are denoted by , and respectively.
Both approaches are, in general, different. But, in this paper it is shown that for most situations which may occur in the field of practical applications in agronomy and plant breeding both procedures will lead to nearly identical results. Only in some special situations the two results differ significantly. These conditions are investigated and explicitly given.
Some explicit formulae (approximations) for the calculation of mean harvest indices are derived and discussed.
Finally, all the theoretical investigations and results are demonstrated and applied to a numerical example of winter-rapeseed data. 相似文献
3.
4.
小麦产量与农艺性状的相关分析和通径分析 总被引：8，自引：0，他引：8
以23个小麦品系为研究对象,采用随机区组试验,设3个重复,对不同农艺性状与产量进行相关性和通径分析,分析参试品系的农艺指标与产量的关系。结果表明,产量三要素与产量的相关系数和通径系数都为穗数>穗粒数>千粒重,穗数与产量之间呈显著正相关,穗粒数、千粒重与产量之间关系呈负相关,但相关性不显著。收获指数、生物产量与子粒产量分别呈极显著和显著正相关,所有品系都有较高的生物产量和收获指数;供试品系的产量与株高和株高构成指数呈正相关,穗长、单穗重与产量之间呈负相关,但相关性不显著。 相似文献
5.
M. Hühn 《Plant Breeding》1992,109(1):28-34
In many fields of application in plant breeding and crop science, ratios of two component traits X and Y are of interest (harvest index in cereals, leaf-to-stem ratio in forage legumes, height-to-diameter ratio in forest trees etc.). When selection is practised on the ratio X/Y of two traits X and Y, the experimenter may be interested in the resulting changes of both trait means. Based on improved approximations for the covariances between X and X/Y and between Y and X/Y and for the variance of X/Y the changes in the means of X and Y can be predicted by applying the regression approach from conventional selection theory. Explicit expressions for these correlated responses in X and Y when selection is practised on their ratio X/Y are derived and discussed. The different outcomes (decrease, zero change or increase) for the selection pressures on X and Y are characterized by phenotypic coefficients of variation of X and Y, phenotypic and genotypic correlations between X and Y and heritabilities of X and Y. 相似文献
6.
M. Özgen 《Journal of Agronomy and Crop Science》1993,170(2):128-135
This study was conducted to determine the stability of grain yield, harvest index, plant height, and panicle length and to determine the association of grain yield with these traits in winter white oat ( Avena sativa L.) genotypes. The genotypes were grown in replicated tests in Ankara in 1985–1991. Each experiment year was regarded as an environment, and entry mean of each year was used as the environmental index. Stability parameters were estimated from the regression analysis as linear regression coefficient (b), deviations from regression (S2 d) and coefficient of determination (r2 ).
Genotypes differed significantly for all traits and significant genotypes X environment interactions occurred for these traits. On the basis of estimates of stability parameters, A-24 genotype was stable for grain yield. Correlation coefficients between traits were inconsistent in good and poor environments except between grain yield and panicle length. The study suggested that these traits are differently affected by environmental changes and selection for panicle length might be effective as selection for grain yield in improving oats with high grain yield for diverse environments. 相似文献
Genotypes differed significantly for all traits and significant genotypes X environment interactions occurred for these traits. On the basis of estimates of stability parameters, A-24 genotype was stable for grain yield. Correlation coefficients between traits were inconsistent in good and poor environments except between grain yield and panicle length. The study suggested that these traits are differently affected by environmental changes and selection for panicle length might be effective as selection for grain yield in improving oats with high grain yield for diverse environments. 相似文献
7.
木薯单株产量与主要农艺性状的相关性研究 总被引：3，自引：0，他引：3
探讨木薯单株产量与主要农艺性状的相关性,以提高木薯育种效率,为木薯品种选育奠定基础。采用13 份木薯种质资源为试验材料,通过相关与通径分析等方法,探讨了11 个主要农艺性状与单株产量之间的相关性以及不同种质资源单株产量之间的差异性。结果表明：NK-2、NK-6、NK-7、NK-10、NK-11、‘新选048’与‘华南205’之间的单株产量呈显著差异;单株产量与块根数呈极显著正相关,与收获指数、生物产量、最长薯长、主茎高度呈显著正相关,与干物质含量呈显著负相关;通径分析结果表明,各农艺性状对单株产量的直接通径系数和决定系数的大小顺序一致,依次为：块根数、最长薯长、生物产量、主茎高度、叶保留高度、干物质含量、收获指数、地上部鲜重、淀粉含量、主茎粗、株高。由此表明,选育高产木薯需要关注的主要农艺性状有：块根数、最长薯长、生物产量、主茎高度、叶保留高度、干物质含量、收获指数等。 相似文献
8.
Summary Improvements in bread wheat productivity have been related to changes in plant morphology and function associated with a large increase in the harvest index for a more or less constant biological yield. The appearance of short genotypes possessing dwarfism genes may modify markedly the objectives of breeding as the upper limits of the harvest index are approached. The aim of the investigations presented here was to identify some contrasts between short and tall genotypes in terms of the physiological characteristics associated with grain yield, so as to orientate more efficiently the selection of genotypes, with or without dwarfism genes, for productivity. Various parameters of flag leaf functioning (photosynthesis rate, chlorophyll fluorescence index, leaf area duration) were related to the biological and economic yields and the harvest index for two groups of genotypes that were differentiated by their height. For all genotypes, the relationships between the various traits and the grain yield were difficult to ascertain. For the tall genotypes without dwarfism genes, the classical relationships between grain yield, harvest index, flag leaf area duration and net photosynthesis rate were confirmed. Moreover, the rate of chlorophyll fluorescence decrease (Rfd) during the slow Kautsky kinetics phase, which is representative of the leaf photosynthesis at low light, was found to be an excellent marker of economic yield. Chlorophyll fluorescence decrease was closely related to grain yield and also with other factors that are known to be important in its expression (harvest index, flag leaf area duration). In very short genotypes, the biological yield and directly related factors (leaf area, plant height) were the main parameters associated with economic yield, since the harvest index had approached its upper limit. The selection of short genotypes must therefore maintain the biological yield through an increase in the size of the aerial organs to counterbalance the decrease in height. 相似文献
9.
The aim of this study was to determine the direction and magnitude of change in morphological and agronomical characters of spring barley ( Hordeum vulgare L.) in Germany over a period of 80 years and to assess the value of various strategies for further crop improvement. Old and new two-rowed cultivars, eight in each case, were tested together with their F2 intra-group diallel crosses in a field trial at Braunschweig-Völkenrode in 1994. New parents and their crosses showed a higher dry matter grain and total biomass yield, a lower plant height, and a higher harvest index as compared to the respective old germplasm. The annual genetic gain in grain yield was estimated at 0.15%. The superior grain yield of the new germplasm was attributable to the higher number of ears per plant and the larger kernel weight. The F2 mid-parent heterosis in grain yield was 7.6 and 7.2 % for the old and new crosses, respectively. The differences between the two types of crosses were nonsignificant except for the higher heterosis for plant height in the new crosses. General combining ability effects were significant for all characters in both types of crosses, whereas specific combining ability effects were significant in a few cases only. In the new crosses, a significant positive correlation was found between grain yield and straw yield (r = 0.52), whereas no such association was observed between grain yield and harvest index. For further gain in grain yield, improvement of the straw yield is more promising than increasing harvest index. 相似文献
10.
Sina Ghanbari Ahmad Nooshkam Barat Ali Fakheri Nafiseh Mahdinezhad 《Journal of Crop Science and Biotechnology》2018,21(5):435-441
18 soybean genotypes were examined to investigate the relationships between some principal attributions of morphology with seed yield per soybean, by Random Complete Block Design (RCBD) study. This study was also carried out three replicates to gain reliable results. The results of variance analysis indicated that, there were significance differences among all soybean genotypes. Moreover, the results of correlated analysis revealed that biological yield (0.96), harvest index (0.92), and number of branches (0.92) had the uttermost correlation with seed yield. To data factor analysis, four independent variables justified 99 percent of all data. The first variable, seed yield, justified 96 percent of entire variance. Multiple-Regression Model with method Analytical Regression Model (step-by-step) was utilized to examine soybean seed yield. This model proved that biological yield, thousand seed weight, and harvest index entered into model respectively and justified 98.85 percent of variation of seed yield. Correlated coefficients of considered attributions were equal to 0.96, 0.78, and 0.92, respectively. All of these indexes had significant at 1% in statistical process. Therefore, these traits can be notability used in soybean breeding programs. Also, accordance to cluster analysis, the sample was divided into three groups. 相似文献
11.
Summary Alternative strategies of multi-site testing of advanced lines in the northern wheat belt of New South Wales have been evaluated, using genetic parameters for large plot grain yield and hill plot harvest index estimated from dryland and irrigated trials at regional sites during 1975–1981. The average pairwise genetic correlation of large plot grain yields recorded at different sites within years was 0.45±.03, with a mean repeatability within trials of 0.56±.05. Harvest index measured in 20-grain hill plots in 1978 showe genetic correlations of 0.98±.08 with plot yield at the same site, and 0.39±0.06 with plot yield assessed at other sites in the same year.The genetic correlation between harvest index in hill plots and total biological yield in large plots at the same site was 0.84±.13, the relationship showing no evidence of curvilinearity. Selection for harvest index in hill plots is therefore expected to lead to an increase in biological yield as well as grain yield in the breeding populations studied. Quantitative genetic theory suggests that the response to selection for grain yield can be increased by approximately 40% with an initial screening using hill plot harvest index at three sites instead of one, and reallocation of resources in the first stage of large plot yield assessment to include 6–8 sites, rather than dryland and irrigated trials at a single location. 相似文献
12.
Ten quite different European winter rapeseed cultivars were grown in a 3-year field trial at one location. The traits grain yield and biomass were measured based on single plant measurements (first year) or on plot basis (second and third year). Individual harvest indices were calculated.
Besides a general discussion of the experimental results for this collection of winter rapeseed cultivars the main aim of the present investigations was an examination whether these experimental results are in agreement with the theoretical conclusions on harvest indices which have been published in this journal in three preceding publications.
Hence the investigations of this paper are divided into the three chapters: 1) Calculation of mean harvest indices, 2) Variability of harvest indices and 3) Correlations among harvest index, grain yield and biomass. In all three chapters the agreement between the empirically obtained and the theoretically expected values is quite good. 相似文献
Besides a general discussion of the experimental results for this collection of winter rapeseed cultivars the main aim of the present investigations was an examination whether these experimental results are in agreement with the theoretical conclusions on harvest indices which have been published in this journal in three preceding publications.
Hence the investigations of this paper are divided into the three chapters: 1) Calculation of mean harvest indices, 2) Variability of harvest indices and 3) Correlations among harvest index, grain yield and biomass. In all three chapters the agreement between the empirically obtained and the theoretically expected values is quite good. 相似文献
13.
Yield responses by modern wheat genotypes to phosphate fertilizer and their implications for breeding 总被引：4，自引：0，他引：4
Summary The response to phosphate fertilizer by modern wheat genotypes was examined in the field under natural rainfall in three seasons. Models were developed which show that grain yield was positively correlated with biological yield and harvest index. In one of the seasons, which was relatively dry, shorter statured wheats gave higher yields at each level of applied phosphate. Higher levels of phosphate tended to offset the reduction in yield associated with late heading and the importance of biological yield on grain yield. The genotypes which produced the largest number of grains m-2 produced the highest yields.Implications for plant breeding programs are discussed. 相似文献
14.
Five barley genotypes of different origins were used to examine the relationships between carbon isotope discrimination (Δ) and grain yield, yield components, dry aerial biomass and harvest index under rainfed and irrigated Mediterranean conditions. High positive correlations were found between Δ and grain yield and harvest index under both water conditions, suggesting that Δ may represent efficiency of dry matter partitioning to the grain. This hypothesis was also supported by the positive correlation found between Δ and thousand-grain weight when all the data were considered. The two drought-tolerant genotypes LM2887 and Tadmor presented the smallest difference between the two treatments for traits related to productivity as well as the highest Δ values. These results highlight the potential of Δ as a selection criterion in barley breeding in Mediterranean regions. They also encourage the study of the genetics of Δ and the identification of molecular markers linked to its variation in available progenies derived from crosses between the genotypes used in the present paper. 相似文献
15.
Analysis of Wheat Cultivar Differences in Grain Yield, Grain Nitrogen Yield and Nitrogen Utilization Efficiency. 总被引：1，自引：0，他引：1
More detailed information on the causes of yield variability among wheat cultivars is needed to further increase wheat yield. Field studies were conducted in Northern Greece over the two cropping seasons of 1985—1986 and 1986—1987 to assess the effects of nitrogen fertilizer and application timing of the various component traits that determine grain yield, grain nitrogen yield and nitrogen utilization efficiency of two bread ( Triticum aestivum L.) and two durum ( Triticum durum Desf.) wheat cultivars, using yield and yield component analysis. Nitrogen at a rate of 150 kg ha-1 was applied before planting or 100 N kg ha-1 before planting and then 50 N kg ha-1 top dressed at early boot stage. Nitrogen and cultivars affected all traits examined, while split nitrogen application affected only some of the traits. Grain yields in the most cases were correlated with number of grains per unit area and grain weight and grain nitrogen yields in all cases with grain number per unit area. The contribution of the number of grains per spike to total variation in grain yield among cultivars was almost consistent (37 to 55 %), while the contribution of grain weight was more significant (up to 55 %) in high yields (>6.500kg ha-1 ) and number of spikes per unit area (>500). The number of grains per spike contributed from 60 to 83 % to the total variation in grain nitrogen per spike. Increased grain nitrogen concentration resulted in a reduction of its contribution in grain nitrogen yield variation. Nitrogen utilization efficiency was higher during grain filling than during vegetative biomass accumulation. The contribution of nitrogen harvest index to the variation of utilization efficiency for grain yield was higher in plants receiving nitrogen application. 相似文献
16.
适合不同产量的环境下油菜高收获指数的产量构成因素分析 总被引：2，自引：0，他引：2
收获指数偏低是制约油菜籽粒产量和产油量进一步提高的瓶颈。为解析适合不同产量的环境下油菜高收获指数的构成因素及形成机制,本研究选择在高产环境下的云南临沧和一般产量的长江流域上游主产区重庆北碚均能正常生长和成熟的321份甘蓝型油菜品种(系)为材料,分析其产量相关性状的变异以及两地间的差异,利用相关分析和通径分析研究籽粒产量收获指数(YHI)、产油量收获指数分别与17个产量组成性状的关系。结果表明,云南高产环境下,油菜高产的主要原因是光照充足、昼夜温差大,导致生物产量高、角果多、每角粒数多,特别是二次分枝角果对产量贡献较大。主序和一、二次分枝的角果数与产量收获指数在重庆均呈显著正相关,而云南环境下主序角果数与产量收获指数呈显著负相关。主序和一、二次分枝的每角粒数均以云南环境下极显著高于重庆环境下,且在两种环境下,主序和一次分枝每角粒数都与产量收获指数和产油量收获指数呈显著正相关,表明每角粒数需要充足的光合产物积累及高效的籽粒填充效率来保证。主序、一次和二次分枝千粒重云南均低于重庆,表明寡日照区域的油菜会减少籽粒数,以保证部分种子的干物质填充。云南环境下,各部位千粒重与产量收获指数和产油量收获指数均呈显著正相关,而重庆环境下的相关性不明显,说明在光照充足条件下,光合产物转运能力是导致千粒重差异的主要原因。综合分析表明,在光照充足的环境下,主序角果数和单株经济产量是提高YHI的关键;而寡日照环境下YHI构成复杂,必须将主序和一次分枝的产量组分有机结合,且严格控制生物产量才能实现YHI的提高。 相似文献
17.
Triticale (X Triticosecale Wittmack) is a cereal that can be simultaneously used for forage and for grain, but this dual purpose is currently limited by a lack of information concerning the effects of forage removal on grain production. Thus, the effect of one or two successive cuttings (simulated grazing) on grain yield, yield components in the main stem and tillers, leaf area and biomass development were studied in four hexaploid triticales grown under irrigation and with high soil fertility. Forage removal reduced grain yield and grain weight per plant in proportion to the number of cuttings, mainly by reducing the number of tillers with spikes at harvest. Whereas foliage reduction did not affect the number of spikelets per spike, kernels per spike, or floral fertility in the main-stem spike, these yield components were drastically reduced in the spikes of tillers. Forage removal affected mean weight per kernel to approximately the same extent in the main stem as in the tillers. The Leaf Area Index (LAI) at anthesis showed significant loss due to cutting, mainly because of a decrease in the number of leaves per plant and in the green area per leaf. This caused similar decreases in the Leaf Area Duration (LAD) from anthesis to maturity. A strong inverse relationship was found between the percent of loss in LAI at anthesis and the final grain yield, suggesting that grain yield was largely dependent upon the ability of the crops to produce new leaf tissue rapidly in the time between cutting and anthesis. 相似文献
18.
S. H. Begna R. I. Hamilton L. M. Dwyer D. W. Stewart D. L. Smith 《Journal of Agronomy and Crop Science》1997,179(1):9-17
Maize hybrids that yield well, mature earlier with low grain moisture contents, tolerate higher population densities and take advantage of narrow row spacings better than the currently available hybrids would be more suitable for production in short-season areas. Leafy reduced-stature maize hybrids, which have only recently been developed, have traits which address these criteria. The objective of this study was to evaluate the effects of different population densities (65 000 and 130000 plants ha?1) and planting patterns (single rows 76 cm apart and paired rows with 20 cm between rows within a pair of 56 cm between rows of adjacent pairs) on the yield and yield components of two leafy reduced-stature (LRS1 and LRS2), one non-leafy reduced-stature (NLRS), and two conventional corn hybrids (Pioneer 3979, < 2500 CHU; and Pioneer 3902, 2600-2700 CHU) at two locations. All hybrids had higher kernel numbers per row and single plant grain yields at the lower population densities when in paired rows. However, as plant density increased, these variables decreased more in the conventional hybrids than the LRS and NLRS hybrids, which demonstrates the greater tolerance of the latter to the stresses associated with higher plant densities. Grain yield was higher for the two LRS hybrids and the NLRS hybrid at 130000 plants ha?1 than 65 000 plants ha?1 Grain yield of conventional hybrids was reduced at the higher population density. The LRS hybrids matured before both conventional hybrids and out yielded Pioneer 3979 at the higher plant population density in both row spacings at both sites. Harvest index was not affected by population density and this value was not different among the NLRS and conventional hybrids. However, the harvest index of the LRS hybrids was greater than the others. LRS and NLRS hybrids had lower moisture contents and earlier maturities than conventional hybrids. Rapid growth of the first ear and higher harvest index values might are indications that LRS hybrids are more tolerant of higher population densities than the conventional hybrids. 相似文献
19.
小麦叶面积及光合速率与产量关系的研究 总被引：3，自引：0，他引：3
选用不同叶片姿态、不同叶片类型以及不同经济系数等多种特性小麦品种(品系)以及拟近等基因系为试验材料,测定了不同叶位叶面积、旗叶光合速率以及小麦生物和经济产量。研究小麦叶面积、旗叶光合速率与产量的关系。结果表明:顶三叶面积与单株生物产量、经济产量显著正相关,而下部三片叶叶面积与单株生物产量和经济产量之间无显著相关;旗叶光合速率与生物产量和经济产量之间呈正相关,但相关不显著,而旗叶光合速率与旗叶面积的乘积与生物产量和经济产量之间呈显著正相关。提高小麦顶三叶面积和光合速率有利于提高产量,旗叶面积和光合速率乘积与产量的关系更为密切。 相似文献
20.
大豆生物量积累、收获指数及产量间的相关与QTL分析 总被引：4，自引：1，他引：3
利用亲本间生物量、收获指数和产量有较大差异的南农1138-2和科丰1号杂交衍生的大豆重组自交家系(NJRIKY), 研究始花期(R1)、始荚期(R3)、始粒期(R5)、收获期生物量以及表观收获指数和产量间的相关, 并进行QTL定位, 分析相关的遗传基础。结果表明, (1) 生物量与产量显著相关, 相关程度随生长进程逐渐增加, 收获期生物量与产量相关最高, R2=0.76。R1、R3、R5期生物量与产量的相关呈负指数曲线相关, 生物量分别达到1 000、2 300和5 500 kg hm-2时, 产量不再随生物量的增加而增加。收获期生物量与产量呈直线正相关, 在试验范围内未发现高产的收获期生物量上限。表观收获指数与产量呈指数曲线相关, 小于0.42时与产量具正变关系, 大于0.42时与产量具负变关系。收获期生物量与表观收获指数呈指数曲线相关, 表观收获指数增加生物量降低。(2) 检测到产量、表观收获指数、收获期生物量有关的QTL分别为9、10和10个, 其中两年稳定的QTL分别有2、3、3个。检测到R1、R3和R5期生物量有关的QTL分别有6、9和6个, 其中3个时期在两年均能稳定表达的有2个。(3)在9个产量QTL中的6个区间, 还同时检测到生物量和表观收获指数有关的QTL, 该3性状有部分QTL共享同一连锁区间, 表明有其共同的遗传基础, 同时也解释了性状间相关的遗传原因。 相似文献