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1.
The usual practice of estimating association and direct and indirect effects among various traits in Gossypium hirsutum is with ungrouped genetic material based on staple length and strength. During 2003–2004 and 2004–2005 genotypic and phenotypic
association among ten characters were estimated in G. hirsutum genotypes: (i) set-1: 10 genotypes of low fibre strength (≤196.2 mN/tex) and medium staple length (≤25.0 mm), (ii) set-2:
10 genotypes of high fibre strength (≥235.44 mN/tex) and long staple length (≥28 mm) and (iii) set-3: 20 genotypes of set-1
and 2. The differences in the estimates of associations, direct and indirect effects for different characters in fibre quality
groups were examined. The complete analysis of variance for the characters under study viz; days to 50% flowering, plant height
(cm), number of monopodial and sympodial branches per plant, seed cotton yield per plant (g), boll weight (g), total number
of bolls per plant, lint %, 2.5% span length (mm) and fibre strength (mN/tex) indicated highly significant genotypic differences
for genotypes, years and genotype × years interaction. Variation within medium staple length and low strength (set-1), high
staple length and high strength genotypes (set-2) and their interaction with year were also significant. Medium staple length
and low strength (set-1) versus high staple length and high strength component (set-2) was significant for all the traits
indicating significant variability between the sets. A true relationship and direct selection were observed for days to 50%
flowering, number of monopodial and sympodial branches per plant with seed cotton yield in the three sets suggesting that
separation of genetic material based on staple length and fibre strength for improvement of seed cotton yield through these
traits is not required. Magnitude and direction of direct effect and association with yield of the other traits; plant height,
number of total bolls per plant, boll weight, lint %, staple length and fibre strength differed between the sets. This study
concluded that more successful planning of a breeding programme can be made through path coefficient analysis if the genetic
material is grouped based on staple length and fibre strength.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Francis Kwame Padi 《Euphytica》2007,158(1-2):11-25
Twenty-four cowpea genotypes were evaluated under sole cropping or additive series intercropping with sorghum from 2004 to
2005 at four sites representative of the Guinea and Sudan savannah ecologies in Ghana. The aim was to determine whether cowpea
breeding programs that emphasize selection under sole-crop conditions have the potential to produce cultivars that are effective
under additive series intercropping. Genotype × cropping systems interaction was significant for days to 50% flowering but
not for grain yield, biomass and other studied traits. Genotypic yield reaction to cropping systems indicated that bridging
the yield gap between sole cropping and intercropping systems is best addressed by agronomic interventions that reduce stress
on intercrop cowpea rather than by selecting for specifically adapted genotypes for intercropping. Significant genotype × environment
interactions were observed for all traits when data was pooled over cropping systems. Partitioning of the genotype × environment
interaction variance indicated that days to 50% flowering was dominated by heterogeneity of genotypic variance, whereas genotype × environment
interactions for grain yield and biomass was mainly due to imperfect correlations. Large differences in genotypic yield stability
were observed as estimated by the among-environment variance, regression of yield on the environmental index, Kataoka’s index,
and by partitioning of genotype × environment interaction sum of squares into components attributable to each genotype. The
results suggest that in regions where genotype × environment interaction for yield frequently causes re-ranking across environments,
genotypes with the least contribution to the interaction sum of squares are likely to be most productive. On the whole, the
results support the contention that breeding under sole-crop conditions has the potential to produce cultivars effective under
intercropping conditions. 相似文献
3.
Oyiga Benedict Chijioke Uguru Michael Ifeanyi Aruah Chineny Blessing 《Journal of Crop Science and Biotechnology》2010,13(1):21-27
Two field experiments were conducted in April (early cropping) and August, (late cropping) 2007 at the Department of Crop
Science Research Farm, University of Nigeria, Nsukka, to evaluate the agronomic and yield attributes of 13 cultivars of bambara
groundnut. The results obtained showed that planting dates had significant effects (P < 0.05) on all traits measured. Significant cultivar and cultivar x planting date interaction effects were observed for days
to 50% flowering. The principal component analysis showed that the first three components accounted for 85.18 and 86.81% of
the total variation in the early and late planting, respectively. The traits representing the cultivars along the first principal
axis were number of pods per plant and seed weight per plant for the early planting and number of leaves per plant and seed
weight per plant in the late planting. Cultivars were differentiated on the basis of number of flowers per plant and plant
height for the early planting and days to emergence for the late planting along the second principal axis. The cluster plot
revealed that the 13 bambara groundnut cultivars were grouped into three clusters at both the early and late planting dates.
In the early planting, the cultivars in cluster I are associated with high number of flowers, number of pods, and plant height,
while cluster II cultivars flowered earlier and had good pod and seed yield. However, cluster III cultivars performed poorly
in all the traits evaluated. During the late planting, the cluster I comprised early flowering cultivars while cluster II
comprised cultivars with good vegetative growth, high number of pods per plant and seed weight per plant. Cluster III cultivars
are early emerging and early flowering but have poor seed yield. The correlation coefficient for seed weight per plant was
highly significant and positive with number of leaves per plant, plant height, number of flowers per plant and number of pods
per plant indicating that increase in these traits will ultimately increase seed weight per plant. Thus, these traits could
be considered as major seed yield contributing traits that could be given significant recognition during selection. 相似文献
4.
5.
Gang Chen Jianfeng Geng Mukhlesur Rahman Xueping Liu Jingxing Tu Tingdong Fu Gengyi Li Peter B. E. McVetty M. Tahir 《Euphytica》2010,175(2):161-174
A genetic map was constructed with 353 sequence-related amplified polymorphism and 34 simple sequence repeat markers in oilseed
rape (Brassica napus L.). The map consists of 19 linkage groups and covers 1,868 cM of the rapeseed genome. A recombinant doubled haploid (DH)
population consisting of 150 lines segregating for oil content and other agronomic traits was produced using standard microspore
culture techniques. The DH lines were phenotyped for days to flowering, oil content in the seed, and seed yield at three locations
for 3 years, generating nine environments. Data from each of the environments were analyzed separately to detect quantitative
trait loci (QTL) for these three phenotypic traits. For oil content, 27 QTL were identified on 14 linkage groups; individual
QTL for oil content explained 4.20–30.20% of the total phenotypic variance. For seed yield, 18 QTL on 11 linkage groups were
identified, and the phenotypic variance for seed yield, as explained by a single locus, ranged from 4.61 to 24.44%. Twenty-two
QTL were also detected for days to flowering, and individual loci explained 4.41–48.28% of the total phenotypic variance. 相似文献
6.
Variation in seed production and its components was investigated between and within four cultivars of the pasture grass Setaria
sphacelata, in two experiments over two years, as a basis for future cultivar improvement. The study sought to determine the
basis for the considerable differences in seed production of the four cultivars Nandi, Narok, Solander and Kazungula, to determine
the extent of genetic variation in the four cultivars in attributes which contribute to seed yield, and to investigate genotypic
consistency in seed production over years and seasons. Each experiment comprised 50 genotypes of each cultivar. In the first
experiment, plants were harvested a set number of days after median flowering date whereas in the second experiment, which
was unreplicated, each genotype was harvested a set number of days after it had flowered. In the first experiment, seed yields
were generally highest for Kazungula, lowest for Narok and intermediate for Nandi and Solander. All measured attributes contributing
to seed yield exhibited a high order of variation between and within cultivars, but the basis for the large difference in
seed yield per plant between cultivars was tiller fertility rather that total tiller number. Averaged over the four harvests,
there was a six fold to > 100–fold intra-cultivar genetic range in seed production, associated with differences in tiller
fertility, which were associated with differences in date of first flowering. Broad sense heritability for seed yield averaged
0.68 for the four cultivars and showed little change over the four harvests. Genotypes which produced high seed yields in
summer were also more productive of seed in autumn and the 0ore productive genotypes in the first year were also more productive
in the second year. Cultivars differed in the relative importance of factors which contributed to the high seed yield of high-yielding
genotypes. In the second experiment, genotypes with a high seed yield also generally had the highest tiller fertility, even
though all genotypes were harvested the same number of days after first flowering. Within-cultivar correlations in seed yield
between the two experiments were generally significant and the elite 20% of genotypes from this experiment had 1.2–2.9 times
the seed yield of the same genotypes with a very different harvesting regime in the first experiment. It is concluded that
opportunities exist in all four cultivars for improvement in seed production and that the selection criterion offering the
best opportunity for advance would be fertile tiller number. In Narok, Solander and Nandi, this would result in increased
tiller fertility, whereas in Kazungula, it would result in an increase in total tiller number.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Summary Two hundred genotypes of Coriandrum sativum L. exhibited genetic variation for plant height, primary and effective branches, days to flowering and maturity, umbels and umbellets per plant, grains per umbellet, thousand seed weight, straw yield and grain yield per plant and harvest index. Heritability estimates were high for days to flowering, thousand seed weight and days to maturity; moderate for plant height, straw yield, umbels per plant, umbellets per plant and number of primary branches; and low for harvest index, effective branches, grain yield per plant and grains per umbellet. Phenotypic correlations of grain yield per plant were highly significant and positive with umbellets per plant, umbels per plant, number of effective branches, straw yield per plant, number of primary branches, plant height, number of grains per umbellet and harvest index. Maximum direct contribution to grain yield per plant was made by umbellets per plant, followed by straw yield per plant, umbels per plant and grains per umbellet. Umbellets per plant made sizeable indirect effect via straw yield per plant. Straw yield per plant made sizeable indirect contribution via umbellets per plant. 相似文献
8.
Vipin Kumar Shailendra Sharma Amit Kumar Sharma Shiveta Sharma K. Venkataramana Bhat 《Euphytica》2009,170(3):249-262
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). 相似文献
9.
This research was conducted to study the genetic diversity in safflower (Carthamus tinctorius L.) using agro-morphological traits and RAPD markers. Sixteen selected lines derived from landraces growing in various agro-climatic
regions of Iran along with four exotic genotypes were evaluated in a randomized complete block design with three replications
under field conditions. Days to emergence, days to initial flowering, days to flowering, days to maturity, plant height, branches
per plant, capitula per plant, seeds per capitulum, 1,000-seed weight, seed yield per plant, seed yield, and reaction to powdery
mildew (Leveillula taurica Arnaud) were evaluated in this study. Genetic diversity of the genotypes was assessed by RAPD markers. The results indicated
significant differences among genotypes for the agro-morphological traits and clustering based on these traits classified
the genotypes into five groups. Analysis of the RAPD markers revealed 15 polymorphic primers out of 50 used primers. Based
on RAPD data, the highest genetic similarity was observed between the cultivars of “AC Sunset,” “AC Sterling” from Canada
and the lowest relatedness observed between a local breeding line “E2428” and genotype “GE62923” from Germany. Cluster analysis based on RAPD markers and 54% coefficient of similarity divided the genotypes into five distinct
groups. Comparing the clusters based on agro-morphological traits with those from molecular markers showed slight similarities.
The finding of high genetic variation for agro-morphological traits and polymorphism at DNA level reveal that agronomic traits
can be improved by selection programs. 相似文献
10.
Ali Mokhtassi Bidgoli Gholam Ali Akbari Mohammad Javad Mirhadi Eskandar Zand Saeid Soufizadeh 《Euphytica》2006,148(3):261-268
Path analysis was performed on plant characters of six safflower genotypes grown in a two year field experiment to determine for seed yield, the direct and indirect effects of the following traits: total biomass, stem yield, number of primary branches/plant, number of secondary branches/plant, number of seeds/m2, number of seeds/capitulum, number of capitula/plant, capitulum diameter, 1000-seed weight, seed weight/capitulum, distance between ground level and the first fertile branch, plant height, number of days to the beginning of branching, number of days to the beginning of flowering, number of days to 50% flowering, number of days to full flowering and flowering duration. Seed yield was significantly correlated with the following traits: total biomass, stem yield, capitulum diameter, 1000-seed weight, seed weight/capitulum, distance between ground level and the first fertile branch, number of days to the beginning of branching and flowering duration. Total biomass, seed weight/capitulum, distance between ground level and the first fertile branch, 1000-seed weight and flowering duration had substantial direct effects, in that order, on enhancement of seed yield. The significant positive correlation coefficient of capitulum diameter with seed yield resulted from positive indirect effects of total biomass, seed weight/capitulum and 1000-seed weight. Conversely, the significant negative correlations between number of days to the beginning of branching and distance between ground level and the first fertile branch and seed yield resulted from negative indirect effects of the same three traits. Stepwise multiple regression analysis showed that 94% of the total variation in seed yield could be explained by variation in total biomass and by number of days to the beginning of branching (84 and 10%, respectively). Results suggest that total biomass and number of days to the beginning of branching are primary selection criteria for improving seed yield in safflower. 相似文献
11.
Summary Fourteen lines of linseed (Linum usitatissimum L.) were evaluated for general and specific combining ability through line × tester cross analysis using five diverse testers in two different environments. Seventy F1's and nineteen parental genotypes were raised in completely randomized block design with two replications with respect to yield and yield related traits. Considerable genetic variation was observed for all the traits studied. The additive as well as non-additive gene effects played significant role in the inheritance of yield and related traits with preponderance of non-additive gene effects for all the traits studied. Higher proportion of general combining ability × environment interaction variance as compared to specific combining ability × environment estimates was recorded. Additive genetic variances were more sensitive than non-additive genetic variances to the changing environment. Low estimates of heritability (narrow sense) for primary branches per plant, capsules per plant, seeds per capsule, seed yield per plant, harvest index and oil content and medium heritability for days to 50% flowering, days to maturity, plant height and 1000-seed weight was observed. Among the female parents LCK-9816, Parvati, Himalini, KL-168 were good general combiners for yield and related traits along with oil content, whereas among male parents, Surbhi and KL-224 were good general combiners for yield related traits and oil content but KL-221 was good general combiner for seed yield and related traits. 相似文献
12.
Field investigations were carried out at the Agricultural College and Research Institute, Madurai, India during 1989—1990 to study the genotypic character association in sesame. The F4 and F5 generations of TSS6 X TMV3 and TMV3 X TSS6 were raised and eight genotypic characters were recorded: plant height; primary branches; secondary branches; capsule number per plant; seed number per capsule; 1000 seed—weight; oil content and seed yield per plant. Correlation studies showed that the magnitude and direction of correlation between eight pairs of traits varied with generations in both crosses involving two genotypes reciprocally. Single plant yield had a strong significant and positive relationship with capsule number in both generations of the two cross combinations indicating the close link between the two traits. The path coefficient analysis revealed that direct and indirect contributions by different traits primary branches, secondary branches, capsule number per plant, seed number per capsule and 1000—seed weight had to be considered as the most important traits in the determination of seed yield and selection of parents. 相似文献
13.
Flower bud thrips, Megalurothrips sjostedti is the most severe field pest of cowpea that causes massive flower abortion which eventually results to substantial yield reduction in Africa. There is paucity of information on the mode of gene actions controlling inheritance of resistance to flower bud thrips in cowpea in the literature. The objectives of study were to assess the genetic variability for thrips resistance among the cowpea germplasm, determined the mode of inheritance of genes that conferred resistance and both broad and narrow-sense heritability estimates for the inheritance of thrips resistance in cowpea. Twelve cowpea lines were used in crosses in the screen house at IITA, Ibadan. The mating was accomplished using North Carolina design II to generate 48F1 hybrids, which were eventually evaluated with the parents. Data on number of peduncles, number of pods and number of thrips per flower were recorded and subjected to analysis of variance using random model by SAS 9.2. Significant variability was observed for most agronomic and thrip-adaptive traits among the cowpea germplasm, parental-lines and F1 genotypes evaluated. General combining ability (GCA) and specific combining ability (SCA) mean squares were significant (P < 0.01) for number of pods per plant and other traits under the research environment. The GCA effect accounted for 68.82–80.07% of the total variation among hybrids for all traits except days to flowering; SCA explained less than 50% of the total variation. Narrow-sense heritability estimates ranged from 7.53 (days to flower) to 63.92% (number of peduncles per plant). Additive gene action largely controlled the inheritance of yield components and other traits under thrips infestation and these traits were moderately heritable. 相似文献
14.
豇豆种质资源农艺性状的相关性、主成分及聚类分析 总被引：2，自引：1，他引：1
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。 相似文献
15.
J. S. Chauhan M. K. Tyagi A. Kumar N. I. Nashaat M. Singh N. B. Singh M. L. Jakhar S. J. Welham 《Plant Breeding》2007,126(4):399-402
Effects of drought on yield and yield components were investigated during the spring season 2000–2001 by growing 14 Indian mustard genotypes under irrigated and rain-fed conditions at Bharatpur and Jobner. A disease and pest management schedule was followed when required. The drought susceptibility index (DSI) for seed yield and component characteristics was calculated to characterize the relative tolerance of genotypes. Plant height, primary branches, secondary branches per plant, 1000-seed weight and seed yield were reduced under rain-fed conditions. The top five genotypes at Bharatpur that showed tolerance to moisture stress for seed yield, as indicated by their lowest DSI, were, in descending order PSR-20, PRO-97024, JMMWR-941, IS-1787 and PCR-7, whereas at Jobner these were JMMWR-941, RC-1446, PSR-20, RH-819 and 'Varuna'. Of these, PSR-20 and JMMWR-941 were among the top six at both locations. These genotypes also showed relatively low DSI for one or more characteristics, such as primary branches per plant, secondary branches per plant, harvest index and seed : husk ratio. Genotypes with the lowest DSI, particularly for seed yield at both locations, would serve as useful donors in the breeding programme for improving the drought tolerance of existing Indian mustard cultivars. 相似文献
16.
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. 相似文献
17.
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. 相似文献
18.
冬小麦性状遗传力的初步研究 总被引：4，自引：0，他引：4
本试验采用遗传变量和表现型变量的比值来估算性状的广义遗传力。估算结果以抽穗期的遗传力最高,达72.04%,一株穗数最低,仅25.57%。穗长、株高、千粒重的遗传力分别为69.21%,66.45%和57.55%。其他性状的遗传力则较低。根据遗传力的估值,对各组合的生产力进行了鉴定。试验指出双亲之一如对当地环境条件很不适应,则遗传力误差很大。双亲如均能适应当地环境条件,则遗传力又可能随双亲的差距而递增。利用变异系数的平方代替相应的变量来估算广义遗传力可以起到一定的矫正作用。 相似文献
19.
Combining ability analysis and association of yield and yield components among selected cowpea lines 总被引：1，自引：0，他引：1
The study was carried out to determine combining ability and association of yield and yield components among crosses derived
from seven selected cowpea (Vigna unguiculata (L.) Walp) parents. Twenty-one hybrids were generated from diallel crosses excluding reciprocals. Hybrids along with seven
parents were studied for combining ability and phenotypic correlations for seed yield and eight yield components. The result
indicated that the general combining ability (gca) and specific combining ability (sca) were significant for most characters indicating the importance of both additive and non-additive genetic components. Additive
gene action was important for eight characters except pod number, whereas non-additive gene action was not important for nodule
number and grain yield. Parental lines IT86D-716 and IT81D-985 were found to be good general combiners for grain yield and
other traits. The most promising specific combiners for yield and yield components were from crosses including IT87D-697-2 × IT86D-716,
IT88D-867-11 × IT86D-716, IT93K-624 × IT87D-697-2, and IT87D-697-2 × IT92KD-405-1. Significant positive phenotypic correlations
were observed between seed yield with pod length (POL), number of pods per plant (PON), and number of seeds per pod (SPD).
POL, pod number per plant, SPD, and grain yield were identified as the best selection criteria that could be used in cowpea
breeding programs. 相似文献
20.
Summary Determinate architecture is of great interest for lupin production in Europe but the extent of genetic and environmental variation in the structure and yield of determinate lupins must be evaluated. Forty-three genotypes of determinate autumn-sown white lupin were studied in four environments in France in 1991/92 and 1992/93. Wide variation was observed for phenological (dates of mainstem and branch flowering, date of end of flowering and date of maturity), morphological (numbers of branch orders, branches and leaves) and seed characters (seed yield, mean seed weight, number of seeds/m2). Both genetic and environmental effects contributed to the observed variation. Heritabilities were high for all characters, and the interaction between genotype and location effects was low. There were significant positive correlations of flowering dates with vegetative plant development including the number of branches, number of leaves and number of branch orders. Seed yield and phenological and archtectural characters were significantly correlated. Distribution of yield on the vegetative orders showed important variations according the genotype, and the variations were related to variation for the architecture. There are possibilities for yield improvement using morphological characters in determinate autumn-sown lupin. 相似文献