利用混合线性模型分析绿豆主要农艺性状的遗传及相关性

以19个绿豆品种(系)为亲本, 采用非完全双列杂交试验设计及混合线性模型,研究绿豆主要农艺性状的遗传规律及其性状间的相互关系。结果表明, 绿豆全生育日数、株高、主茎节数和百粒重均以加性效应为主, 狭义遗传率较高且达极显著水平;单株荚数、单株产量和总产量的加性效应和显性效应均显著或极显著, 狭义遗传率相对较低;单荚粒数主要受显性效应影响, 广义遗传率较高;播种至开花天数与株高间存在显著或极显著遗传和表型正相关;单株荚数、单荚粒数与百粒重显著或极显著负相关;单株荚数与单株产量、总产量显著或极显著正相关;百粒重与单株产量、总产量相关性不大;针对全生育日数、株高、主茎节数和百粒重的选择可在早期世代进行, 而对产量的选择可以根据单株荚数和单株产量在晚期世代进行。     

Genetic control of alfalfa seed yield and its components

Seed yield is of little agronomic importance in alfalfa (lucerne) but is critical in the marketing of varieties. In order to develop breeding criteria, the quantitative genetics of seed yield components must be studied. The objective of this study was (1) to evaluate combining ability for seed yield and its components and (2) to estimate the genetic control of these same characters. A 7 × 7 diallel mating design, including reciprocals, among parents from different varieties, and a 7 × 7 factorial design within the ‘Flamande’ population were evaluated. In the diallel design, where the progenies were evaluated over two growing seasons, a high genotype effect was found for seed yield and its components while genotype × year interaction was only significant for seed yield per plant. General combining ability (GCA) effects explained most of the variation due to genotype effect. Specific combining ability (SCA) and reciprocal effects were only significant for seed yield per plant. ‘Europe‐1’, ‘Rival‐5’ and ‘Medalfa‐7’ were the most promising parents, conferring the highest GCA for most of the characters evaluated, especially for seed weight per inflorescence. In the factorial design, seed weight per pod was the only character for which the year effect was not significant. Male and female effects were significant for all characters and these effects were larger than the male × female interaction variance for all the characters. These results were stable over the 2 years for most characters. Additive variance was larger than dominance variance, for all traits. This resulted in high narrow‐sense heritabilities, especially for seed yield per plant, seed weight per inflorescence and number of seeds per pod. Seed weight per inflorescence and number of seeds per inflorescence were highly correlated with seed yield per plant among the full‐sib (FS) families, in both experiments. Increase in seed yield potential in alfalfa could be achieved by the use of seed weight per inflorescence as a selection criterion.     

黑龙江省中熟大豆品种主要农艺性状演变趋势分析

黑龙江省近20年来中熟大豆品种遗传改进的明显趋势是株高、有效节数、一二粒荚数、三四粒荚数、单株荚数、单株粒数、每荚粒数和单株粒重增加,底荚高度略有增加。分枝数、蛋白质含量呈现先增后减的趋势．脂肪含量呈现先减后增的趋势,百粒重变化不大。株高、有效节数、三四粒荚数、单株荚数、单株粒数、百粒重与单株粒重呈显著或极显著的正相关。各性状对单株粒重的贡献大小依次为单株粒数、单株荚数、三四粒荚数、株高、有效节数、百粒重。提高单株粒数、单株荚数、三四粒荚数．兼顾株高、有效节数、百粒重是该区大豆育种的主攻方向。     

Inheritance of yield components and their correlation with yield in cowpea (Vigna unguiculata (L.) Walp.)

Summary The inheritance of yield components was studied in a cross of two varieties of cowpea (Vigna unguiculata), and the relationships among the components and yield were examined in the F₂ of a cross and in a trial of 22 varieties. The main objective was to determine the suitability of using the components as selection criteria for increasing seed yield. All the components appeared to be under polygenic control and transgressive segregation in the F₂ was observed for pod length and number of seeds per pod. Narrow sense heritability estimates ranged from 19.8% for number of pods per plant to 60.3% for pod length. Most of the genotypic correlations between pairs of yield components were significant. Correlation of yield per plant was negative with pod length, but positive with the other components. Number of pods per plant was consistently correlated with yield. However because of low heritability for number of pods per plant, this component may only be used as a preliminary selection criterion while the final selection is based on yield itself.     

Analysis of quantitative variability for seed yield and related characters in Lotus corniculatus L. cv. Leo

Summary Quantitative variability for seed yield and six other characters was analysed in Lotus corniculatus L. cv. Leo. The material consisted of 144 polycross progenies and 100 parents.Wide variability existed for all characters. The characters with the greatest variability were seed yield, forage grading and plant height. The polycross progeny test was employed to study the general combining ability of the parents. Highly significant differences existed for all seven characters under study.Parent-offspring genotypic and phenotypic correlations were high and significant for all characters except genotypic correlations for seed yield and seeds per pod. High h² values (broad sense) were obtained for seed size and days to flowering. Traits with moderate to high h² were seed yield (71% in parents, 64% in progenies), plant height, forage grading, and seeds per pod. The character pods per inflorescence had the lowest h².Positive estimates of % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabiGaaiaacaqabeaadaqaaqaaaOqaaiqabo8agaqcaK% aaavaabeqaceaaaeaacaqGYaaabaGaaeiraaaaaaa!3A89!\[{\text{\hat \sigma }}\begin{array}{*{20}c} {\text{2}} \\ {\text{D}} \\ \end{array} \] were obtained only for seed size. The ratio of dominance variance to additive variance indicated partial dominance for this character. Except for seed yield, in all other cases these estimates had very high sampling errors. In all cases except pods per inflorescence and seeds per pod high positive estimates of % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabiGaaiaacaqabeaadaqaaqaaaOqaaiqbeo8aZzaaja% qbaeqabiqaaaqcaauaaiaaikdaaKaaGeaacaqGbbaaaaaa!3B30!\[\hat \sigma \begin{array}{*{20}c} 2 \\ {\text{A}} \\ \end{array} \] were obtained.The data indicated that it may be possible to simultaneously improve seed yield and maintain forage yield. Seed yield had positive and significant associations with seed size, seeds per pod and pods per inflorescence. The associations of days to flowering with forage grading (negative) and with pods per inflorescence (positive) were also significant.     

豇豆种质资源农艺性状的相关性、主成分及聚类分析

为给豇豆育种中品种资源的合理利用提供依据,对41份豇豆品种资源15项主要农艺性状进行相关性、主成分和聚类分析。结果表明,枯萎病发生程度的变异系数最大,与豇豆产量关系密切的单荚重和单株嫩荚数2个农艺性状,与株型、嫩荚长、单株花序数和单荚种子粒数都呈现显著正相关,单株嫩荚数与开花期、叶宽和单株分枝数呈现显著负相关。15个主要农艺性状可以归纳为5个主成分,第1主成分包括株型、初花节位、嫩荚长、单荚重、单荚种子粒数、单株花序数、单株嫩荚数和单株分枝数;第2主成分包括开花期、叶长和叶宽;第3主成分包括种皮颜色和嫩荚宽;第4主成分包括嫩荚颜色;第5主成分包括枯萎病发生程度。41份豇豆种质资源在遗传距离为25处分为2大类,在遗传距离为15处分为Ⅰ、Ⅱ、Ⅲ类,其中第Ⅰ类的品种优势明显,具有较好的应用前景。     

生育期结构不同的大豆品种的光周其反应和农艺性状

分别选用成熟期相近、开花期不同及开花期相近、成熟期不同的南方春、夏大豆品种,研究了生育期结构与开花前、后光周期反应敏感性的关系。结果表明,大豆品种生育前、后期长短与它们在该期的光周期反应敏感性正相关。在生育期相近的前提下,前期长度与开花促进率（ＦＨＲ）、后期长度与成熟促进率（ＭＨＲ）正相关;开花期相近的品种,后期长度与ＭＨＲ值正相关。部分品种不符合以上趋势,反映出上述相关的复杂性。在生育期相近的南     

Components of Seed and Straw Yield in Common Vetch (Vicia sativa L.)

178 common vetch (Vicia sativa L.) strains were tested for 2 years under dryland conditions in Bursa, Turkey. Broad-sense heritability of the traits was calculated for each trait. Phenotypic and genotypic correlation coefficients between seed and straw yield, with several morphological and reproductive traits, were obtained. Broad-sense heritability estimates were high for 1000-seed weight and number of seeds per pod. Heritability values for both seed and straw yield were small and insignificant. Harvest index, 1000-seed weight and spring vigour showed significant positive correlations with seed yield, but days to flower correlated negatively with seed yield. Spring vigour, plant height and number of leaflets per leaf correlated positively, while harvest index, seeds per pod and seeds per plant correlated negatively with straw yield. Correlations between seed and straw yield were both positive and significant.     

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.     

Variance components and heritabilities of yield and agronomic traits among cowpea genotypes

The phenotypic expression and heritability of quantitative traits vary due to genotypic differences, environmental influences and genotype by environment interactions. The objective of this study was to determine variance components and heritabilities of seed yield and its components in cowpea. Field experiments were conducted at three locations, three planting dates using ten diverse cowpea genotypes during 2004/2005. The experiments were laid out in the randomized complete block design with three replications. Results indicated significant interactions (P ≤ 0.01) among genotypes, locations and planting dates. The genotypic variance contributed ≥50% of the total phenotypic variance for the numbers of days to 50% flowering, seeds per pod, productive branches per plant and seed yield. The heritabilities of the numbers of days to 50% flowering were estimated at 50%, pods per plant (23%), days to maturity (66%), productive branches per plant (53%), 100 seed weight (11%) and seed yield (55%). The presence of considerable degree of genotypic variance among tested genotypes under various environments suggests that success in cowpea breeding could possibly be achieved through direct phenotypic selection.     

Yield, yield components and plant architecture in the F3 generation of common bean (Phaseolus vulgaris L.) derived from a cross between the determinate cultivar ‘Prelude’ and an indeterminate landrace

Growth trials were conducted outdoors in the UK to determine the yield, yield components and plant architectural differences between determinate and indeterminate Phaseolus vulgaris bean plants. F3 lines derived from crosses between ‘Prelude’, a determinate cultivar and ‘V8’, an indeterminate landrace, were grown together with the parents and ‘Carioca’, an indeterminate landrace from Brazil. Data were recorded on flowering date, number of nodes on main stem at flowering, plant height at maturity, number of pods/plant, number of seeds/pod, number of seeds/plant, 100-seed weight, seed mass/plant, percentages of diseased and healthy seeds/plant. Determinate F3 lines had significantly lower (P < 0.05) seed mass/plant, fewer pods/plant, fewer seeds/pod, fewer seeds/plant, lower harvest index, shorter stems, earlier date of flowering, fewer nodes at flowering and fewer healthy seeds/plant than indeterminate F3 lines. However, determinate genotypes had significantly larger (P < 0.05) pods to accommodate their larger seeds compared with indeterminate lines. A similar situation was found when the yield and yield components of ‘V8’, ‘Prelude’ and ‘Carioca’ were evaluated; the highest seed mass/plant was given by ‘V8’ and the lowest by ‘Prelude’. Furthermore, some indeterminate genotypes with Type IV growth habit yielded significantly higher (P < 0.05) than the high-yielding parent, ‘V8’, indicating a positive influence on seed yield by crossing different genotypes.     

Triple Test Cross Analysis in F2 Populations of Four Promising Crosses of Field Pea

The components of genetic variation were studied in four F₂ crosses (PG₃× 5064, T₁₆₃× B.V., T₁₆₃× Arkel and 5064 × ED) for quantitative characters such as days to flowering, plant height, pod number, seed number, test weight and yield/plant. The overall epistasis (T type) was, in general, a major contributor for genetically controlling the expression of the characters in all the- four crosses except for the character seed number in crosses 1 and JV, where the j + l component at epistasis played a significant role in determining the expression of this attribute:. Though the ‘j + l’ component of the epistasis was significant, it was relatively less important than the ‘i’ type epistasis. Both the additive and dominance components of the genetic variation were highly significant for all the trans studied in all die four sets of crosses. The expression of the dominance was directional only for a few characters in certain crosses. The degree of dominance lies in the partial range, and heritability estimates obtained were high for most of the trails. The possible application of cross prediction in the isolation of superior recombinant inbred lines in pea is discussed.     

Genotype × cropping system interaction in climbing beans (Phaseolus vulgaris L.) grown as sole crop and in association with maize (Zea mays L.)

The selection of cultivars for the predominant cropping systems of small farms in the tropics depends to a large extent on the information obtained by testing their performance across the different systems. The main objective of this experiment was to measure the genotype × cropping system (G × CS) interaction for yield and selected agronomic traits of climbing beans (Phaseolus vulgaris L.) grown as sole crop and intercropped with two morphologically contrasting maize (Zea mays L.) cultivars. A secondary objective was to identify the most efficient and productive bean–maize intercrop combinations. Seven climbing bean genotypes were grown as sole crop and intercropped with two maize varieties, BH 140 (Mix. 1) and Guto (Mix. 2), in a factorial arranged Randomized Complete Block Design with three replications at Bako Agricultural Research Center in western Ethiopia. Main effects due to genotype and cropping system (except days to flowering) were significant for all bean traits considered. The genotypes × cropping system interaction terms were also significant for the number of seeds per pod, 100-seed weight, harvest index and seed yield. While bean seed yield significantly correlated with the number of seeds per pod (in Mix. 1) and with harvest index (in both mixtures), positive and significant correlations occurred with the number of pods per plant and 100-seed weight under sole cropping system. The correlation between bean seed yields of Mix. 1 and Mix. 2 and between Mix. 2 and sole crop were positive and significant. No such relationship was found between Mix. 1 and sole crop. The results suggest that selection of suitable climbing bean cultivars for intercropping with maize varieties predominantly grown in the area should be made under the associated culture of the two crops. Intercropping contributed to a significant reduction in seed yield of the bean genotypes due mainly to its adverse effects on the numbers of pods per plant and seeds per pod. The index tLER₁ identified most bean–maize genotype combinations of Mix. 2 as biologically more efficient system than Mix. 1. On the other hand, tLER₂ values of more than 1.00 for all treatments of Mix. 2 demonstrated higher overall productivity of the intercrop system when the bean genotypes were grown in association with a late-maturing and high yielding maize hybrid BH 140.     

Comparative analysis of diversity based on morpho-agronomic traits and microsatellite markers in common bean

Morpho-agronomic traits and microsatellite markers were used to survey genetic diversity in 115 common bean genotypes that included 70 Indian landraces, 24 released varieties and 21 exotic accessions. Twelve morpho-agronomic traits, namely, days to 50% flowering, leaflet length, leaflet width, pod length, pod width, number of pods per plant, days to maturity, seed length, seed width, number of seeds per pod, 100 seed weight and seed yield per plant were studied. Field data of two consecutive years were subjected to multivariate analysis as proposed by Mahalanobis’s D²-statistics, Tochers method of clustering and combined analysis of variance. Seventeen microsatellite markers were also used to examine genetic diversity at molecular level that showed polymorphic information content (PIC) in the range of 0.00–0.684. Dendrograms based on Euclidean distances and UPGMA analysis showed the presence of majority of released varieties into single cluster, which pointed toward their low genetic base in comparison to indigenous landraces and exotic germplasm. Significant correlation existed between morphological genetic distance and microsatellite genetic distance tested by Mantel test (r = 0.876).     

Diallel cross analysis of seed germination traits in sugar beet

A diallel cross design, involving six diploid O-type lines and their cytoplasmic male sterile (CMS) equivalents was used to examine the genetic control of characters determining seed viability and vigor of seed and seedling in sugar beet. Six characters including percentage of germination, seedling establishment, weight of 1000 germs, seedling vigor, speed of germination, and monogermity were analyzed. Additive genetic effects were shown to be highly important for all characters and significant dominance effects were found for the percentage of germination and seedling establishment, weight of 1000 germs, and rate of monogerm seeds produced by multigerm plants. There were significant reciprocal variations for most characters, indicating that maternal effects and differences of self-incompatibility mechanisms may influence the expression of some characteristics related to the amount of viable seeds produced in plant. Variance of genotypes for seedling vigor and speed of germination was nonsignificant, indicating that both characters are mainly affected by environmental factors. The relative importance of heritability estimates and the ratio of GCA, SCA, and environmental variances to phenotypic variances were calculated for all the traits examined. It is suggested that seed traits are as important as root quality traits for the development of sugar beet varieties. This revised version was published online in August 2006 with corrections to the Cover Date.     

Genetics of Seed Yield and its Components in Common Bean (Phaseolus vulgaris L.) of Middle-American Origin

Genetic variance, heritability, and expected response from selection arc useful in devising alternative methods and criteria of: selection. The objectives of this study were to estimate these for seed yield and its components from 200 F₂: populations involving 80 cultivars and lines of mostly small-seeded dry bush bean (Phaseolus vulgaris L.) of habits growth I, II, and III of Middle-American origin. All cultivars and lines were crossed in eight sets of ten parents each in a Design II mating system. The F₂ populations, without parents, were evaluated in the field in a replicates-in-sets design at two locations in Colombia in 1983. Estimates of additive genetic variance were significant for yield, pods/m², seeds/pod, and seed weight. Interaction with environments was also significant. Values for nonadditive genetic variance were not significant for either yield or yield components. The estimates of narrow sense heritability, based on the F₂ population mean and unbiased by genotype x environment interaction, were 0.21 ± 0.13 for yield. 20 ± 0.13 for pods/m², 0.57 ± 0.13 for seeds/pod, and 0.74 ± 0.15 for seed weight. The expected direct response from selection of the top 20 % of F₂ populations for yield per se would result in a 4.30 % increase in yield with a correlated response of 0.21 % in seed weight. In contrast, the expected gain from direct selection for seed weight would result in a 11.76 % increase in seed weight with a, correlated gain of 0.28 % for yield. Direct selection for pods/m² would decrease yield, seeds/pod and seed weight, while direct selection for seeds/pod would reduce pods/m² and seed weight but increase seed yield by 0.37 %. Data on yield from replicated trials in the early segregating generations could be utilized for identification and selection of promising crosses and families or lines with crosses for dry bean yield improvement.     

Phenotypic recurrent selection in common bean (Phaseolus vulgaris L.) based on performance of S2 progenies

Summary The effect of a recurrent selection procedure for improving seed yield per plant was evaluated in common bean. Progress was registered after three cycles of recurrent selection with S2 progeny evaluation performed on the grain yield/plant. Gain from selection was estimated by field testing 45 random S2 lines from each of the C0, C1 and C2 populations. Response to selection for seed yield/plant was 6 g from C0 to C1 and 4.4 g from C1 to C2. The seed yield improvement was due principally to an increase in pods/plant; little contribution was provided by the 1000-seed weight and seeds/pod traits. Broad-sense heritability and genotypic variance for grain yield remained high in all cycles which suggests further gain from additional selection cycles. Grain yield/plant is significantly correlated to pods/plant and seeds/pod traits in all cycles, indicating that plants with favourable combinations of these traits could be identified. The proposed recurrent selection procedure appears to be effective in improving the population and extracting superior genotypes for varietal development.     

晋北绿豆主要农艺性状变异及对产量构成的影响

研究绿豆新品种（系）主要农艺性状的变异及其在产量构成中的作用,为绿豆高产体系的建立提供科学依据。以国家食用豆产业技术体系绿豆新品种（系）联合鉴定试验（2016-2017年）的25份绿豆新品种（系）为试验材料,对其株高、主茎节数、单株荚数等8个农艺性状进行了变异、相关及通径分析。结果表明,荚粒数变异系数最小,仅7.30%（2017年）,产量变异最广泛,变异系数为35.86%（2016年）;产量除与荚长（r=0.609）、荚粒数（r=0.679）呈极显著正相关外,与其他性状相关不显著;通径分析结果表明,对产量的直接通径系数荚长>株高>荚粒数>单株荚数>百粒重>主茎分枝数>主茎节数,并且株高、单株荚数、荚粒数、荚长和百粒重对产量的直接作用为正值,主茎节数、主茎分枝数对产量的直接作用为负值;综合分析表明,在绿豆高产育种中,荚粒数受外界环境影响较小,与产量的相关性最大,且直接与间接效应均表现优良,应作为主要研究对象。荚长和百粒重的直接效应和间接效应均为正值,也应作为主要筛选对象,同时还要兼顾其他性状的相互影响与均衡发展,充分挖掘种质资源潜力。     

60Co-γ射线诱导豇豆M2代群体变异分析及突变株筛选

为了获得豇豆诱变材料,用₆₀Co-γ射线诱变豇豆品种早生王和詹豇215的干种子,统计M₂代的育性,并对7个农艺性状变异程度进行相关分析和聚类分析,结果表明：M₂代群体中产生一些白化苗、纤弱苗或无花粉的不育株,正常结实植株的农艺性状变异系数增大,依次为：分枝数＞结荚数＞有效花梗数＞初花节位＞最大荚长＞平均荚长＞开花期,其中前三者之间呈极显著正相关;最大荚长与平均荚长,开花期与初花节位呈极显著正相关;开花期与结荚数呈极显著负相关。M₂代均可聚为6个类群,早生王的性状变异株率为27.49%,詹豇215为24.55%,并分别从中筛选出变异株33个和40个。以分枝数、结荚数、有效花梗数为重点考察性状,有利获得变异个体,其中结荚数对丰产型材料筛选具有更重要意义。     

Variation in traits affecting nodulation of common bean under intercropping with maize and sole cropping

Common bean (Phaseolus vulgaris L.), an important food crop in Europe, America, Africa and Asia, is thought to fix only small amounts of atmospheric nitrogen. It contributes significantly to the sustainability of traditional cropping systems because of the predominance of small-scale farmers who cultivate beans in those areas. The objectives of this work were to evaluate bush bean varieties under common agronomic cropping systems and to evaluate breeding lines under low N-fertility sole cropping and intercropping systems. The purpose of the study was to characterize the genotype and cropping system's variability in symbiotic and plant characters and to identify the most suitable genotypes to establish an effective symbiosis with indigenous strains of Rhizobium. No significant differences among the bush bean varieties evaluated under typical fertilization practices were observed for N₂-fixation and plant traits except for seed nitrogen. Significant differences among the bean lines studied under low N-fertilization conditions were detected for plant growth,plant component and N₂-fixation traits. A significant interaction of bean genotype x cropping system was found for number of nodules per plant and nodule moisture on the bush bean varieties studied, and for days to emergence, days to flowering, end of flowering, shoot length, root dry weight and shoot nitrogen on the bean lines evaluated. Nodulation parameters were correlated positively with the yield components, shoot and root parts and duration of flowering, and correlated negatively with seed crude protein, pod and seed dimensions and seed dry weight. These observations indicate that it may be possible to increase both the symbiotic N₂-fixation and seed yield through plant breeding. This revised version was published online in August 2006 with corrections to the Cover Date.