Top PDF Diallel analysis in cotton (Gossypium hirsutum L.) for water stress tolerance

Diallel analysis in cotton (Gossypium hirsutum L.) for water stress tolerance

Diallel analysis in cotton (Gossypium hirsutum L.) for water stress tolerance

The results of ANOVA (Table 2) showed that significant statistic differences (p<0.05) were verified in Genotype (G), Year (Y) and Water Treatment (WT) to all traits, excepting to boll weight (BW) in year (Y) and water treatment (WT). For these source of variation, the F test uses the interaction Y x WT. As it was very high and significant for this trait, it caused no-significance effect for them (Y and WT). The same results were seen for G x WT, that uses G x Y x WT interaction to test it, indicating different behavior of cultivars submitted to water treatments. On the other hand, the interaction G x Y did not demonstrate significant effect indicating that the genotypes had similar behaviors in both years (2014 and 2015). The CV values ranged from 2.14 for LP to 10.48% for CSY, and they are in accordance with the results found by Carvalho et al. (2015), Carvalho et al. (2016) and Zonta et al. (2016) for this crop. The means of traits (Table 3), obtained from different hybrid combinations submitted to two water treatments, demonstrate that the water suppression influenced the growth and production of plants at different levels. For all traits, some hybrid averages showed good potential to develop new genotypes with better performance in water stress condition. The number of groups formed by Scott- Knott test ranged from two groups (PH) to seven groups (LP). These results are expected due to the differences among the genetic variability and the influence of the environment in each trait. The reduction in height ranged from 12.88 to 24.71%. This difference promoted a direct impact in yield, with losses ranging from 3.08 to 44.78%. These results explain the effect seen in G x WT, in which some combinations were more negatively impacted by water stress, such as FMT 705 x BRS Seridó (1 x 9) with yield reduced of 44.78%, revealing a highly sensitive genotype. In contrast, BRS 286 x CNPA
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Expression of heat shock protein and trehalose-6-phosphate synthase homologues induced during water deficit in cotton

Expression of heat shock protein and trehalose-6-phosphate synthase homologues induced during water deficit in cotton

Tolerance to drought in plants is not a simple trait, but a complex of mechanisms working in combination to avoid or to resist water deficit. Genotypes that differ in tolerance to water deficit may show qualitative and quantitative differences in gene expression when submitted to drought periods. Four cotton (Gossypium hirsutum L.) genotypes (Siokra L-23, Stoneville 506, CS 50 and T- 1521) with contrasting responses to water deficit stress were studied using the Differential Display (DD) technique to identify and isolate genes which may differ among them. Fifty-two cDNA fragments differentially expressed during water deficit were iso- lated, cloned and sequenced. Search of gene bank databases showed that two cDNA clones, A12B15-6 and A12B13-1, have high homology with a heat shock protein that binds to calmodulin found in Nicotiana tabacum (2.9e-32 P(N)) and with an Arabidopsis thaliana trehalose-6-phosphate synthase enzyme (9.0e-37 P(N)), respectively. One of the presumed functions of heat shock pro- teins is related to prevention of protein denaturation during cellular dehydration. Trehalose-6-phosphate synthase is involved in the production of trehalose, a disaccharide known to osmotically protect cell membranes during dehydration. The HSP homologue was found to be differentially expressed during the drought period in two drought tolerant genotypes but not in drought-sensitive genotypes. The trehalose-6-phosphate synthase homologue was also up-regulated during water deficit stress, however, all four genotypes were induced to express this homologue. Ribonuclease protection assays confirmed these results. This is an important finding since there are only few reports of trehalose presence in higher plants and none in cotton.
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Evaluation of water-stress tolerance of Acala SJ 2 and Auburn 2 cotton cultivars in a phenotyping platform

Evaluation of water-stress tolerance of Acala SJ 2 and Auburn 2 cotton cultivars in a phenotyping platform

Cotton (Gossypium hirsutum L. r. latifolium) is the major fiber crop in the world; however, cotton yields are often limited due to the sensitivity of this crop to environmental stresses, such as temperature variation and drought (Brito et al., 2014b; Luo et al., 2016). Drought may result in reductions in yield of up to 30% compared to that of well-irrigated conditions, especially when the stress of drought occurs during flowering and fructification (Brito et al., 2011; B2014a). The quantity and the quality of the cotton fiber produced are directly related to the availability of water in the soil during the plant’s phenological stages, especially during the initial reproductive phase. Drought during the fiber-elongation period results in decreased fiber length. Water stress after fiber elongation leads to fiber immaturity and low micronaire, a measure denoting fiber fineness and maturity (Selvam et al., 2009).
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Salt Tolerance Evaluation in Cotton (Gossypium hirsutum L.) Using RAPD Marker

Salt Tolerance Evaluation in Cotton (Gossypium hirsutum L.) Using RAPD Marker

ratio and protein pattern expression) as selection criteria, have been previously investigated in cotton under salt stress (Saleh 2011, 2013). Our data presented herein are in agreement with the physiological characteristics previously exhibited by the examined varieties (N78, DE22, DP50 and A118) where the former two varieties were superior to the latter (Saleh 2011, 2013). The amplified fragments which proved to be specific for the relatively high salinity tolerant N78 and DE22 varieties, may serve as markers for early evaluation/screening for salinity tolerance in cotton. Dojan et al. (2012) reported the potential of RAPD marker for detection DNA damages induced by NaCl in cotton. The previous investigation stated that RAPD analysis could be considered as useful biomarker assay for observing environmental stresses such as high salinity in cotton. Whereas, Mohamed and Abdel-
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Analysis of natural variation in bermudagrass (Cynodon dactylon) reveals physiological responses underlying drought tolerance.

Analysis of natural variation in bermudagrass (Cynodon dactylon) reveals physiological responses underlying drought tolerance.

pressure of cytoplasm and environment, so higher proline content provides a significant advantage for plants to advent different stresses [6,23]. The soluble total sugars are also important osmolytes and sucrose is the major soluble sugar in plant [6,23]. In this study, the results indicated that proline and soluble sugar accumulations were significant higher in drought tolerant bermudagrass (Tifgreen) than those of the other varieties under water-deficit condition, leading the cells to improve the drought tolerance by osmotic adjustment (Fig. 5). Increased proline content might increase the osmotic pressure inside plant cells and cause more water uptake to keep a significantly increase in LWC. This result was consistent with previous researches which showed that proline accumulation and soluble sugars were positive related with drought tolerance in many plant species [23,24,25]. Moreover, water loss is a key for plant survival during drought stress condition. The results of rapid leaf water loss (Fig. 1) were consistent with changes of long term leaf water content (Fig. 4), i.e. drought tolerant bermudagrass variety exhibited lower leaf water loss, and therefore higher leaf water content. Higher amount of Figure 7. Antioxidant enzyme activities of three bermudagrass varieties differing in drought tolerance during drought stress. (A)– (E) Comparisons of SOD (A), CAT (B), POD (C), GR (D) and GPX (E) activities three represent drought tolerant, moderately tolerant and susceptible accessions under control condition and drought stress were shown here. The relative activities were quantified as fold change in comparison with Yukon under control conditions for 7 d. The results shown are mean 6 SE (n = 4). Asterisk symbols indicate significant differences between Yukon and other genotypes (P,0.05).
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Transcriptome Analysis of Sunflower Genotypes with Contrasting Oxidative Stress Tolerance Reveals Individual- and Combined- Biotic and Abiotic Stress Tolerance Mechanisms.

Transcriptome Analysis of Sunflower Genotypes with Contrasting Oxidative Stress Tolerance Reveals Individual- and Combined- Biotic and Abiotic Stress Tolerance Mechanisms.

map the genes to identify associated pathways and based on biological function, those genes were found to be involved in oxidation reduction process (S7 Fig). Similarly in the large num- ber of down regulated genes were involved in developmental processes, hormone responses, defense responses, transcription, translational events and protein modifications (S8 Fig). The genes involved in plant development, including anatomical structure (23 genes), flower (8 genes), pollen (6 genes) and seed (8 genes) development responsive genes were downregulated. The downregulated genes with response to stimulus include multicellular organismal process (34 genes), responses to stress (34 genes), responses to chemical stimulus (28 genes), abiotic stimulus (19 genes) and defense responsive (14 genes). The genes that were involved in many biosynthetic process (57 genes), macromolecular biological process (82 genes), catabolic pro- cess (16 genes), macromolecule modification (25 genes), protein modification (24 genes) and post translational modification (20 genes) were downregulated. Based on these results and lit- erature information [73] we hypothesised that oxidative stress tolerance mechanisms are linked to tolerance of plants to multiple number of individual stresses and also combined stresses. Menadione induces oxidative stress and broad-spectrum stress effects Menadione, a compound that produces superoxide radicals, has been used to induce oxidative stress in plants [50, 74, 75]. Seedlings (two day old) of var. Morden were treated with different concentrations of menadione and response was recorded after recovery. Mild concentrations of menadione (0.25 to 2 mM for 2 h) reduced the shoot and root growth compared to that of water treated controls. Root and shoot growth was reduced at concentration higher than 3 mM
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Germination of cotton cultivar seeds under water stress induced by polyethyleneglycol-6000

Germination of cotton cultivar seeds under water stress induced by polyethyleneglycol-6000

Germination was completely inhibited at water potential -1.0 MPa. Similar data were obtained by Pereira et al. (1998) who found significant effects on germination percentages for ten genotypes, PEG-6000 simulated osmotic potentials, and for the interaction between these two factors. Similarly to the observations in the present study, they also observed com- plete inhibition of average germination percentage at -1.0 MPa. Ghajari and Zeinali (2003) studied the effect of drought and salinity on the germination and growth of plantlets of two cotton cultivars (‘Sahel’ and ‘Bakhtegan’). They applied water potentials varying from -0.1 to -1.0 MPa induced by PEG-6000 and NaCl, and found that the germination per- centage and the percentage of normal plants increased, both under salinity and osmosis. Ghajari and Zeinali (2003) also observed an increase in radicle length until -0.2 MPa when using PEG-6000. The ‘Bakhtegan’ cultivar was more toler- ant to salinity than the ‘Sahel’ cultivar, but under the condi- tions simulated with PEG-6000, tolerance and germination of ‘Bakhtegan’ were inferior to ‘Sahel’, thus classifying the two cultivars according to sensitivity to this type of stress, as seen in this work.
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Germination and tolerance of cowpea (Vigna unguiculata) cultivars to water stress

Germination and tolerance of cowpea (Vigna unguiculata) cultivars to water stress

The obtained data were subjected to analysis of variance by F test and, in cases of significance, the Scott-Knott means grouping test was applied to the factor genotypes and Student’s t-test was applied to the factor osmotic potential levels, both at 0.05 probability level, using the statistical program Sisvar® (Ferreira, 2011). The data were subjected to standardization to have mean equal to zero (X = 0) and variance equal to one (σ = 1). Then, cluster analysis was carried out using a hierarchical method, Ward’s minimum variance, considering the Euclidean distance as measure of dissimilarity (Hair et al., 2009).
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Water contamination reduces the tolerance of coral larvae to thermal stress.

Water contamination reduces the tolerance of coral larvae to thermal stress.

signifying that overall, the combined effects of these stressors were not additive. The effects of SST and Cu on metamorphosis success were strongly non-linear making ANOVA inappropriate for detection of the nature of the interaction [38]. However the modelling technique and isobologram analysis employed here were effective tools for identifying regions of the parameter space which gave rise to synergistic versus antagonistic interactions. The model was used to calculate expected 10%, 50% and 80% metamorphosis success contours for additivity. These contours were almost vertical up to 31 uC when plotted as isobolograms for both species (Fig. 4A and 4B), indicating little or no expected effect of temperature on toxicity in this region. As temperature started to affect metamorphosis (.31uC), the additive effects of temperature and Cu concentration were expected to cause a rapid decrease in metamorphosis as Cu increased. The strength of interaction between SST and Cu was quantified by dividing the observed effect on metamorphosis by the expected additive effect from the modeled data. The interaction plot (Fig. 4C) indicated sub- additivity (interaction ratio, IR ,1) at low temperature-Cu combinations for A. millepora, increasing to additive effects at temperatures less than 31uC and then becoming strongly synergistic (IR.1) at temperatures between 31uC and 33uC and Cu concentrations up to 30 m g l 21 . The response of A. tenuis was similar; however, there was little apparent sub-additivity and the range of temperature and Cu concentrations where metamorpho- sis was reduced by 50% more than expected for additivity (IR = 1.5) was broader for this species (Fig. 4d). Overall, Cu contamination and temperature stress had a stronger synergistic effect in inhibiting metamorphosis of A. tenuis compared to A. millepora, although the latter species was generally more sensitive to these stressors. Three other studies have examined the combined effects of SST and pollution on adult corals but these used fewer treatment combinations, or a narrower range of treatments, making interactions more difficult to quantify. Nystrom et al. [39] found that the combination of elevated SST (ambient and 4uC above ambient) and Cu (0 and 11 m g L 21 ) did not interact to affect coral metabolism. Two other studies found that the effect of the herbicides on photosynthesis of coral symbionts decreased as temperature increased from 26 to 30 uC, indicative of an antagonistic interaction [40,41]. Nevertheless, the latter study also showed that two herbicides acted synergistically with higher SSTs Figure 3. Environmental thresholds for larval metamorphosis
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Genetic analysis of earliness indicators in upland cotton

Genetic analysis of earliness indicators in upland cotton

Crop maturity duration is critical in all agricultural crops. However, in the cotton crop, it is of prime importance because short duration cotton varieties ensure food security by allowing in time sowing of wheat. In cotton, a number of plant characters are involved in determining the maturity duration of the crop thus making it very complex. Considering the vitality of this issue, different morphological and phenological traits related to earliness in cotton were studied using diallel analysis. It is a useful biometric technique which gives comprehensive information on the genetic components of variation. In previous investigations node for 1st fruiting branch and days to 1st boll opening were used as effective selection criteria for the estimation of earliness in cotton [6, 12, 26]. In the research work presented here, although additive component was significant in the inheritance of days taken to appear first square yet the low heritability of this trait made it unfit to be used as earliness indicator. Besides low heritability, square abscission is common due to environmental stress in terms of high temperature and insect damage as reported by [11] among other phenological measures, days to first flower and days to first boll opening, vertical and horizontal flowering intervals were controlled by additive variation. Heritability estimates recorded for these traits were reliable due to which these could be used as efficient indicators of earliness in breeding programs conducted to improve maturity duration in cotton crop [5, 13, 17, 25]. In other studies [11, 22, 26] reported that days to 1st flower, days to 1st boll opening, and node for 1st fruiting branches were additively controlled and in contrast the studies by [24] showed that days to flowering and days to boll opening were controlled by non-additive gene effects. Parents used in this experiment showed reduced flowering duration which could be of great utility in avoiding boll damage caused by the late season insect attack. Another phenological character studied was boll maturity period for which parents showed delayed ripening. This might be accounted for a significant environmental component of variation because earlier researchers have indicated that boll maturation period is largely temperature dependent
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DIALLEL ANALYSIS OF TOLERANCE TO DROUGHT IN COWPEA GENOTYPES

DIALLEL ANALYSIS OF TOLERANCE TO DROUGHT IN COWPEA GENOTYPES

Most cowpea crops in Brazil are conducted under rainfed conditions, subjecting the crops to risks of dry spells and rainfall below the required levels throughout the crop cycle. Water deficit is the most limiting abiotic factor for increasing cowpea production in Brazil. The main challenge for grain production has been to prevent losses due to water deficit, which is the most limiting environmental factor for crop production around the world, especially in semiarid regions (FRITSCHE-NETO; BORÉM, 2011). The low use of technologies by farmers and the occurrence of biotic and abiotic stresses are limiting factors for cowpea production in the Brazilian Northeast region.
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Diallel analysis in white oat cultivars subjected to water stress

Diallel analysis in white oat cultivars subjected to water stress

Low GCA values usually do not differ between them, which can be explained by the masking presence of small effect complementary genes in the parental genotypes involved in the crosses (Barbieri et al. 2001). For the character MPW, it can be observed that the cultivar UPF 18 showed a high individual mean, much higher than the general mean for the environment without stress. However, its GCA value (0.53) was not very high (Table 3). Regarding the environment with water stress, all parents showed a performance inferior to the general mean for the character. The correct selection of parental genotypes to form the crossing blocks is essential to the success of plant breeding programs, and the combining ability, with the presence of complementary genes, the major player in this process. Parents presenting higher GCA must be preferred to be part of crossing blocks, favoring the selection of promising homozygous lines in self crossing species (Miranda et al. 1988). A very low g i estimate indicates that
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Diallel analysis for frogeye leaf spot resistance in soybean (1)

Diallel analysis for frogeye leaf spot resistance in soybean (1)

Twenty days after inoculation, when the disease symp- toms were stablished, the following characters were evalu- ated: infection degree (ID), a visual evaluation of the symp- toms and application of a grading scale, from 1.0, without apparent infection, to 5.0, the maximum infection degree; number of lesions per leaflet (NLF), on the most infected leaflet of the plant; lesion mean diameter (LMD), average of the 10 largest lesions of the most infected leaflet, in millimeters; number of lesions per square centimeter (NLC), the number of lesions per leaflet divided by the area of the leaflet; percentage of lesioned foliar area (PLFA), the lesioned foliar area divided by the area of the leaflet and multiplied by one hundred; and disease index (DI), the
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Osmotic stress tolerance, PGP traits and RAPD analysis of Bradyrhizobium japonicum strains

Osmotic stress tolerance, PGP traits and RAPD analysis of Bradyrhizobium japonicum strains

with findings reported by BOIERO et al. (2007) and JOSIC et al. (2010) for other B. japonicum strains. However, MAHMOUD and ABD - ALLA (2001) tested several rhizobium and bradyrhizobium strains and all strains showed a positive reaction on CAS medium. Experiments of ANTOUN et al. (1998) demonstrated siderophore production in several strains of different rhizobial species, but less percentage of B. japonicum strains, showed positive reaction. Bradyrhizobia may not possess highly developed iron acquisition systems, having evolved in the acid soils of the tropics, where iron is more generally available than in neutral or high pH soils ( MAHMOUD and ABD - ALLA , 2001). Iron is essential in symbiotic nitrogen fixation, but the ability of strains to produce siderophore does not always limit binding of nitrogen ( AHEMAD and KHAN , 2011). This can be explained by
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The friction influence on stress in micro extrusion

The friction influence on stress in micro extrusion

At the interface, a rough layer of a tool – workpiece, a zero friction shear factor m has been given. This assumption gave a possibility to observe a flow of a extruded material along triangle roughness wave without conventional friction disturbance. In that case, resistance of the rigid asperity to billet movement was treated as a friction. To determine the distribution of friction along the wall of the container, substitute friction shear factor m z

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Diallel analysis in cowpea aiming at selection for extra-earliness

Diallel analysis in cowpea aiming at selection for extra-earliness

The values of GCA esimates for PH ranged from -0.953 (MNC04-789B-119-2-3-1) to 1.053 (AU94-MOB-816). The parents AU94-MOB-816 and IT82D-60 stood out, showing great potenial for improving the expression of this trait. GCA esimates for PL ranged from -0.760 to 1.611. The most favorable esimates for this trait were obtained by IT82D-889 and MNC04-789B-119-2-3-1, with values of 1.611and 0.095, respecively. Among these parents, IT82D-889 stood out for presening GCA esimate superior to the other parents. All parents were signiicant for this trait, except for MNC04- 789B-119-2-3-1. For NGP, all parents showed signiicant efects. The highest esimates were 0.188 and 0.142 for AU94- MOB-816 and IT82D-889, respecively. The parent MNC05-820B-240 had the highest GCA esimate for W100G. For PY, all parents showed signiicant efects, except for IT82D-60. The parents AU94-MOB-816 and MNC05-820B-240 showed the highest GCA esimate for PY, proving to be promising for the use in programs aimed at yield increase. According to Lorencei et al. (2005), the choice of parents for the formaion of segregaing populaions is crucial for the success of a breeding program, and the combining ability with the presence of complementary genes is responsible for the success of the crosses.
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EVALUATION FOR SALT STRESS TOLERANCE IN TWO STRAWBERRY CULTIVARS

EVALUATION FOR SALT STRESS TOLERANCE IN TWO STRAWBERRY CULTIVARS

Uniform two strawberry cultivars (Camarosa and Albino) transplants were used in this experiment. The transplants were planted in plastic pots (20 cm in diameter and 20 cm in height), containing sandy loam soil in a partially controlled greenhouse located at Agricultural Research Station which belonged to College of Agriculture, University of Mutah. One 4 weeks old transplant was planted in each pot. At the bottom of each pot, there were many holes to facilitate drainage water. Transplants were irrigated with distilled water two times weekly; after 15 days of transplantation, sex levels of NaCl (0, 25, 50, 75, 100 and 150 mM) were added to the irrigation water. Nutrient elements were added at the 0.5- strength Hoagland nutrient concentration (Hoagland and Arnon, 1950). Distil water supplemented with half strength Hoagland solution was used as control.
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Plantas de cana-de-açúcar (Saccharum spp.) transformadas geneticamente com o gene...

Plantas de cana-de-açúcar (Saccharum spp.) transformadas geneticamente com o gene...

osmotolerance in transgenic plants. Plant Physiology, Rockvile, v.108, p.1387-1394, 1995. KISHOR, P. B. K.; SANGAM, S.; AMRUTHA, R. N.; LAXMI, P. S.; NAIDU, K. R.; RAO, K. R. S. S.; RAO, S.; REDDY, K. J.; THERIAPPAN, P.; SREENIVASULU, N. Regulation of proline biosynthesis, degradation, uptake and transport in higher plants: Its implications in plant growth and abiotic stress tolerance. Current Science, Bangalore, v. 88, n. 3, 2005. KOUWENBERG, L. L. R.; KÜRSCHNER, W. M.; VISSCHER, H. Changes in stomatal frequency and size during elongation of Tsuga heterophyla Needles. Annals of Botany, London, v. 94, p. 561-569, 2004.
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THEORY AND ANALYSIS OF PARTIAL DIALLEL CROSSES

THEORY AND ANALYSIS OF PARTIAL DIALLEL CROSSES

Estimates of the regression coefficients show the presence of statistically nonsignificant positive unidirec- tional dominance. This seems to indicate that many non- fixed dominant genes act to decrease yield, although the majority of them increase it. Estimates of the average de- gree of dominance are larger than one, although previous results indicate complete dominance. It is reasonable, there- fore, to admit that they are statistically equal to one. As there is evidence of complete dominance, estimates of the proportion among dominant and recessive genes suggest that the parents in group 1 have, on average, more reces- sive than dominant genes, while in group 2 the parents have, on average, the same number of recessive and domi- nant genes. These results agree with those from the analy- ses of the parent F values, as the majority of the parents in group 1 have more recessive than dominant genes, while in group 2 the majority have equal numbers of dominant and recessive genes.
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Analysis of variance of partial diallel tables

Analysis of variance of partial diallel tables

The theory of variance analysis of partial diallel tables, following Hayman’s proposal of 1954, is presented. As several statistical tests yield similar inferences, the present analysis mainly proposes to assess genetic variability in two groups of parents and to study specific, varietal and mean heteroses. Testing the nullity of specific heteroses equals testing absence of dominance. Testing equality of varietal heteroses of the parents of a group is equivalent to testing the hypothesis that in the other group allelic genes have the same frequency. Rejection of the hypothesis that the mean heterosis is null indicates dominance. The information obtained complements that provided by diallel analysis involving parents and their F 1 hybrids or F 2 generations. An example with the common bean is included.
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