Segregation pattern and inbreeding depression in F 2 generation of some hybrid okra varieties

An experiment was conducted in randomized complete block design (RCBD) with three replications in the experimental field of Regional Horticulture Research Station (RHRS), Bangladesh Agriculture Research Institute (BARI), Lebukhali, Patuakhali during April, 2014 to October, 2014 for assessing the inbreeding depression, genetic parameters, gene action and segregation pattern of Okra [Abelmoschusesculentus (L.) Moench]. The experiment was comprised of five commercial hybrid Okra genotypes such as Tara sonali, Bimala, Juboraj, Suvo 1and Noor, their respective F2 progenies along with a check variety named as BARI Dherosh 1. Results of the experiment indicated that there were considerable variability among the F1 and their F2. The yield were in-between 14.81 to 7.92 Kg plot -1 in case of F1 generation, which deteriorate to 10.32 to 5.32 Kg plot -1 in F2 generation. Broad sense heritability computed through variance component method showed that all the quantitative traits were moderate to highly heritable. The trait yield per plot exhibited 68.83% broad sense heritability coupled with 50.96% genetic advance suggesting the existence of sufficient amount of genetic variability for improvement of this trait and also indicates that the trait is more amenable to selection and could be improved easily. In case of segregation pattern, plant height and pod pubescence content exhibit as polygenic trait. Leaf shape, fruit base shape and branching pattern showed complete dominance and fruit color displayed incomplete dominance. The present investigation thus provide information about the nature and magnitude of genetic variation, segregation pattern and inbreeding depression for yield and its components in okra so as to formulate suitable breeding strategy and isolate potential parents and promising crosses for further breeding program.


Introduction
Okra [Abelmoschusesculentus(L.)Moench] is a member under Malvaceae Family and is also known as Lady's finger.It is an annual vegetable crop grown from seed in tropical and sub-tropical parts of the world (Tahkur and Arora, 1986).Okra is a nutritious and delicious vegetable, fairly rich in vitamins and minerals.Per 100 gm. of edible portion of pod have moderate levels of vitamin A (0.01 mg) and C (18 g), calcium (90 mg), phosphorus and potassium.The content of thiamine (0.07 mg), riboflavin (0.08 mg) and niacin (0.08 mg) per 100 g edible portion of pod is higher than that of many vegetables (Rashid, 1990).Abelmoschusspp.ispredominantly annual.Owing to their floral morphology and the absence of a self-incompatibility system, they are generally regenerated through selfing.However, depending on the species or variety, season and location, varying degree of outcrossing (up to 6(%) occurs in okra.Bees (ApismelliferaandA. cerana) appear to be the main vectors of pollen.Such a level of out crossing will maintain a considerable amount of heterozygosity and heterogeneity, eventually resulting in off-type segregants during repeated multiplication cycles.Since okra is an autogamous crop, the breeding methods suitable for the self-pollinated crops can usefully be employed in this crop also.The crop offers several features viz.adaptability to wide range of climatic conditions, erect growing habit, short life span, large size flower and monoadelphous and epipetalous nature of stamens which have a great value to breeder in achieving quick genetic results.Large size flowers and monoadephours condition of stamens facilitate hand emasculation.Its capsule produces a large number of seeds which is also a desirable feature for hybrid seed production.Being a short duration crop, it is possible to grow two generations in a year.Despite these qualities, no systematic studies have been made to generate information on quantitative traits which may be directly or indirectly related to yield and further improvement of this crop.Genetic variability in the population is the most important prerequisite of any breeding program.Variability, only accounts for the observable phenotypic differences, which may be of genetic and environmental.Higher variability has better chance for selecting the desirable genotypes.Furthermore, the partitioning of total variability into its heritable and non-heritable components enables us to know the effectiveness of selection.Heritability, which indicates the transmissibility of the character from parent to offspring, is a useful measure for considering the ratio of genetic variance to the total variance.It may be based on total genetic variance and additive genetic variance, where latter is more important in selection breeding.Heritability indicates the possibility and extent to which improvement can be brought about through selection and it may be of broad and narrow senses.However, heritability alone does not provide the true picture of genetic improvement to be made in subsequent generations.It is the genetic advance which predicts speed of genetic improvement for a particular intensity of selection.Heritability coupled with genetic advance is more useful, and as heritability and phenotypic variation increases, the genetic advance also increases.Thus, the primary requirement of a plant breeder is to have information on the genetic advance and direct and indirect influences of the plant characters on yield.The nature and degree of association between yield and its attributes claims distinct importance which assist the breeder to ascertain the actual yield components and furnish an effective basis of phenotypic selection.Inbreeding depression defines to decrease in fitness and vigor due to inbreeding effect.It increases homozygosity in the genotype by continuous selfing.It results due to fixation of undesirable recessive genes in F 2 .While in case of heterosis, favorable dominant genes of one parent are masking the effect of recessive genes of other parent.The present investigation was, therefore, undertaken with a set of self-crosses to elicit information about the nature and magnitude of genetic variation, segregation pattern and inbreeding depression for yield and its components in okra so as to formulate suitable breeding strategy and isolate potential parents and promising crosses for further exploitation.

Location and description of the experimental site
A field experiment was conducted at the Research field of Regional Horticulture Research Station (RHRS), Lebukhali, Dumki, Patuakhali during the period from may, 2014 to September, 2014 to study on segregating pattern and inbreeding depression of some hybrid okra varieties in Second filial generation (F 2 ).This region occupies a vast area of tidal floodplain land in the North-West part of Patuakhali district.

Experimental materials
A total of eleven materials were used in this experiment.Among the materials, five were commercial F 1 okra varieties; five were their F 2 generations and one check variety.The okra variety used in the experiment was Tara Sonali, Bimala, Noor, Suvo-1 and Juboraj and their F 2 derivatives with the cheak variety BARI Dherosh 1.F 2 seeds were collected from Regional Horticulture Research Station (RHRS), Lebukhali, Dumki, Patuakhali and F 1 's were collected from different seed retailers of Barisal.

Layout and design of experiment
The experiment was laid out in RCBD with three replications.The whole field was divided into three blocks and each block consisted of eleven (11) plots.The replications were separated from one another by 1 m.The distance between plots was 50 cm.The treatment was randomly assigned to each of the block.However, Each F 1 and its respective F 2 were planted side by side.Plot size for F 1' s and checks variety was 1m x 4m.

Collection of data
Morphological data were collected from five randomly selected plants for each accession based on International Board for Plant Genetic Resources (IBPGR) recommended descriptor procedures for Okra (Charrier, 1984).Data were collected as specified.These are:

Days to 50% flowering
Recorded as days from sowing to flowering when 50% of the plant of each plot flowered.

First harvesting date
Recorded as days from sowing to 1 st harvesting when fruit become edible.

Node order of 1st flowering
Node order of 1 st fruiting of ten randomly selected plants was counted at fruit setting from the 1 st node of the plant to the 1 st fruiting node.

No of fruit per plant
Mean number of green pods of selected plants from each plot was recorded.

Fruit weight
Mean weight of ten randomly selected green fruit from each plot were measured in gram (g).

Plant height
Plant height is measured in centimeter (cm) by a meter scale at harvest from the point of attachment of the leaf to the ground level up to the tip.It was classified into 6 classes namely; 60-90 cm, 90-120 cm, 120-150 cm, 150-180 cm, 180-210cm and 210-240 cm.Number of plant per class were counted and recorded.

Fruit Length
Ten randomly selected pods from each plot were taken and length was recorded by a meter scale in cm and finally mean was calculated.

Fruit Diameter
Mean diameter of 10 randomly selected pods from each plot were measured in cm with the help of slide calipers.

Yield per plot
The weight of individual fruit was recorded during each fruit harvesting and was continued up to final harvesting.Thus, total weight was calculated to get fruit weight per plot and expressed in kilogram.

2.4.9.Internodal length
Recorded as the distance (cm) from the node to node, twenty random internode were selected from different plant of a plot and the average was taken.

Statistical analysis
Analysis of variance was done for all the characters under study using the mean values (Singh and Chaudhury, 1985).Duncan's Multiple Range test (DMRT) was performed for all the characters to test the difference between the means of the genotypes following Steel and Torrie (1960).i) Estimation of genotypic and phenotypic variances Genotypic and phenotypic variances were estimated according to the formula given by Johnson et al. (1955).iii) Estimation of heritability Heritability in broad sense was estimated using the formula suggested by Johnson el al. (1955) andHanson, et al. (1956).
Where Genotypic variance Phenotypic variance iv) Estimation of genetic advance Expected genetic advance under selection was estimated using the formula suggested by Johnson et al. (1955).

Genotypic variance
Phenotypic variance k = selection intensity, the value of which is 2.06 at 5% selection intensity.
Phenotypic standard deviation.v) Estimation of genetic advance in percent of mean Genetic advance in percent of mean was calculated as proposed by Comstock and Robinson (1952).
Where, GA = genetic advance X = population mean

Estimation of inbreeding depression
Inbreeding depression was measured using F 1 and F 2 means values according to the following formula:

Estimation of segregating pattern
The selfing ratio was tested using a chi-square test (Panse and Sukhatme, 1985).The confirmation of ratios obtained in F 2 segregating populations was done by the ratios obtained fromF 1 generation.
Where, O = Observed value E = Expected value When the calculated value of χ 2 was less than the table value at (n-1) degree of freedom, the fit was considered to be good or the assumed ratio was correct.Conversely, when the calculated value was more than the table value, the fit was not good and the assumed ratio was not correct.Probability values were recorded for these ratios (Deokar, 1964) for their respective test crosses ratios.

Performance of F 1 and F 2 progenies
Days to 50 % flowering were ranged from 39.00 days after sowing to 62.00 days after sowing with mean value 50.27.Maximum days required for 50% flowering in F 2 generation of Noor which was followed by Noor (F 1 ) itself.Minimum days for 50% flowering were obtained in F 2 progeny of Juboraj (41 DAS).In most cases, the F 2 progenies took more time for 50% flowering then their respective F 1.However, in Juboraj it was almost similar in two generations.Days to 1 st harvest ranged from 62.33 DAS to 51.33 DAS with mean value 57.33.Maximum days required for 1 st harvesting was in F 2 progeny of Suvo 1 and Noor which was 62.33 DAS.Minimum days for 1 st harvesting were required in F 2 progeny of Juboraj which was 51.33 DAS.In all cases, harvesting took more time in F 2 progenies then their respective F 1 progenies but in Juboraj F 2 progeny took less time than its F 1 for 1 st harvesting.Node order for 1 st flowering ranged from6.23 to 11.03 and there was significant variation among the genotypes for the characters. 1 st flowering was obtained in 11 th node in F 2 progeny of Bimala and Suvo-1, and in Tara sonali (F 1 ), it was found in 6 th node.Significant variation was observed for the character number of fruit per plant.Number of fruit per plant ranged from 6.93 to 15.37.Maximum fruiting was found in Tara sonali (F 1 ) and minimum in F 2 progeny of Noor.In all cases, number of fruit was higher in F 1 then their respective F 2 progenies.
There was significant variation among the materials for individual fruit weight.Maximum fruit weight was found in Juboraj (F 1 ) (21.23g) which was almost similar in Noor (F 1 ) (21g).Smallest fruit was found in F 2 progeny of Suvo-1 (15.53 g).Mean value for this character was 17.86 g. in all cases F 1 produced larger fruit then their respective F 2 progenies.Plant height ranged from 107.9 cm to 131.8 cm and variation for this character was highly significant.Maximum plant height was found in F 2 progeny of tarasonali (131.8 cm and minimum was found in Noor (F 1 ) and Suvo-1 (F 1 ) (107.9 cm).in all cases, F 1 produced smaller plant than their respective F 2 progenies.Significant variation was obtained for intermodal length.This value ranged from 7.20 cm to 11.13 cm.Maximum node length was found in F 2 progeny of Juboraj (11.13 cm) and minimum in Bimala (F 1 ) (7.20 cm). in Tara sonali, internodal length decreased in F 2 .But in all other cases, this value increased in F 2 than their respective F 1 .Fruit length showed significant variation among the materials.This value ranged from 11.98 cm to 18.78 cm.longest fruit was obtained in Tara sonali (F 1 ) (18.78 cm) and shortest fruit was found in F 2 progeny of Noor (11.98 cm).Fruit length was decreased in F 2 progenies then their respective F 1 's .
There was significant variation for fruit diameter.Fruit diameter ranged from 1.27 cm to 1.70 cm.maximum fruit diameter was found in Juboraj (F 1 ) and minimum in F 2 progeny of Noor.In Tara sonali, fruit diameter increased in F 2 progeny but for other cases it was reduced in F 2. Significant variation was obtained for yield per plot.Yield ranged from 5.32 kg per plot to 14.81 kg per plot.Maximum yield was obtained from Juboraj (F 1 ) (14.81 kg) and minimum yield was found in F 2 progeny of Noor (5.32 kg).Yield reduced in F 2 progenies than their respective F 1 's.

Heritability, genetic advance and genetic advance in percentage of mean
The genotypic, phenotypic and environmental variance, genotypic co-efficient of variation (GCV), phenotypic co-efficient of variation (PCV), heritability in broad sense (h²b %), genetic advance (GA) and genetic advance in percent of mean (GA %) for all the quantitative characters under study are presented in table 6 respectively.The phenotypic co-efficient of variation (PCV) were higher than their corresponding genotypic co-efficient of variation (GCV) for all the characters studied indicating that they all interacted with the environment to some intent.Genetic parameters in respect of all characters are presented below:

50% flowering
In case of first filial generation, genotypic (13.56%) and phenotypic (14.72%) co-efficient of variation was moderate for days to 50% flowering in the present study.Days to 50% flowering exhibited low heritability (25.75%) in broad sense (h 2 b ) coupled with moderate genetic advance in percentage of mean (12.95).

Days to 1 st harvesting
Genotypic (6.48%) and phenotypic (6.98 %) co-efficient of variation was low for days to 1 st harvesting in the present study.Days to 1 st harvesting exhibited low heritability (12.39 %) in broad sense (h 2 b ) coupled with low genetic advance in percentage of mean (7.10).

Node order of 1 st flowering
Genotypic (16.86%) and phenotypic (21.03%) co-efficient of variation was moderate for node order of 1 st flowering in the present study.Node order of 1 st flowering exhibited low heritability (27.83%) in broad sense (h 2 b ) coupled with low genetic advance in percentage of mean (2.41).5).

Plant height
Genotypic (6.64%) and phenotypic (9.48%) co-efficient of variation was low for plant height.Plant height exhibited low heritability (9.60%) in broad sense (h 2 b ) coupled with moderate genetic advance in percentage of mean (11.47) (Table 5).

Internodal length
Genotypic (10.69%) and phenotypic (16.51%) co-efficient of variation was moderate for internodal length in the present study.Internodal length exhibited low heritability (14.26%) in broad sense (h 2 b ) coupled with low genetic advance in percentage of mean (1.36) (Table 5).

Fruit length
Genotypic (12.72%) and phenotypic (15.01%) co-efficient of variation was moderate for fruit length.Fruit Length exhibited low heritability (22.21%) in broad sense (h 2 b ) coupled with low genetic advance in percentage of mean (3.16) (Table 5).

Fruit diameter
Genotypic (7.84%) and phenotypic (11.85%) co-efficient of variation was low for fruit diameter in the present study.Fruit diameter exhibited low heritability (10.68%) in broad sense (h 2 b ) coupled with low genetic advance in percentage of mean (0.15) (Table 5).

Yield
Genotypic (29.81%) and phenotypic (35.92%) co-efficient of variation was high for yield per plot.Yield per plot exhibited moderate heritability (50.96%) in broad sense (h 2 b ) coupled with low genetic advance in percentage of mean (4.69) (Table 5).

Inbreeding depression
Inbreeding is a system of mating that leads to an increase in homozygosity, decline in vigor and the reduction in productivity.Inbreeding depression may be defined as the reduction or loss in vigour and fertility as a result of inbreeding.The character wise results of inbreeding depression in F 2 generation are given as under.

Yield
The results of inbreeding depression for the character Yield per plot are presented in Table 7. Inbreeding depression was very prominent in all the varieties for yield.It was 14.64%, 41.12%, 37.07%, 34.22% and 32.82% respectively in Tara sonali, Bimala, Juboraj, Suvo-1 and Noor respectively.

Segregation pattern 3.4.1. Plant height
Segregation pattern of plant height of Okra were studied in five selfed F 2 progenies.In Figure 1, it is clear that plant height of Okra cannot be classified into distinct categories.It is probably, due to multiple genes controlling this character.

Leaf shape
It is easy to explain from the Figure 2 that the leaf shape segregated into two major different types of shapes.
Almost one fourth number of plants studied exhibited alternate palmately lobed leaf types, while a large number of plants exhibited heart shape leaf in F 2 generation.The dominant and the recessive character for leaf shape: heart shape and alternate palmately lobed leaf types were easily distinguishable (Figure 2).All of the varieties showed fair to very good goodness of fit, which support the expected ratio 3:1.

Pod pubescence content
The pods of Juboraj F 1 and Noor F 1 have pubescence while Tara SonaliF 1 , Bimala F 1 and Suvo 1F 1 does not have pubescence.Segregation took place in the F 2 plants giving two phenotypic classes for both types of parents.The ratio of the classes in F 2 offspring of Juboraj and Noor is very close to 3:1 ratio.The P value of χ2 is (P = 0.10-0.25 and 0.25-0.50)indicating that the deviation from the expected frequencies is not significant i.e. there is a good fit to a 3:1 ratio.But the ratio of the classes in F 2 offspring of Tara Sonali, Bimala and Suvo-1is far from3:1 ratio.This is probably due to presence of polygenic gene for this trait.

Fruit base shape
The Fruit base shape of all varieties of F 1 was round.Segregation took place in the F 2 plants giving two phenotypic classes namely, round and ridge.The ratio of the classes in F 2 offspring is very close to 3:1 ratio.The P value of χ2 is indicating that the deviation from the expected frequencies is not significant i.e. there is a good fit to a 3:1 ratio.

Branching pattern
The branching pattern of all varieties of F 1 was branched.Segregation took place in the F 2 plants giving two phenotypic classes namely, unbranched and branched.The ratio of the classes in F 2 offspring is very close to 3:1 ratio.The P value of χ2 is indicating that the deviation from the expected frequencies is not significant i.e. there is a good fit to a 3:1 ratio.

Fruit color
Inheritance studies for fruit color were studied in five selfed F 2 varieties.It is easy to explain from the Fig. that the fruit color segregated into three major different colors.Almost an equal number of plants studied exhibited deep green and yellowish green color, while a large number of plants exhibited light green color in the F 2 generation.The two homozygous extremes for fruit color: dark and yellowish green were easily distinguishable.Non significant chi-squared values were observed for the segregating ratios in F 2 generation.Observations of 1 dark green: 2 light green: 1 yellowish green, fruit color was observed in the F 2 populations.The segregation of the fruit color in F 2 generation into three classes: dark green, light green and yellowish green fitting into the theoretical 1:2:1 monohybrid ratio of incomplete dominance.

Discussion
Genetic improvement of any crop depends upon the nature and extent of genetic variability available and also on the magnitude of interrelationships of heritable and non-heritable variation in yield and its major contributing characters.If such genetic variability is not available locally, plant breeder should have an idea of the availability of genetic diversity of the breeding material.This would ensure organized and systematic hybridization program for creating genetic variability to be exploited for genetic improvement of the trait under consideration.The information about heterotic potential among okra gene pool and early filial populations is essential to optimize the possible use of F 2 hybrid seed in order to reduce the cost of hybrid seed development.
In the present study, an attempt has been made to understand the genetic system controlling inheritance of some qualitative characters and heritability and inbreeding depression.Investigations were therefore made on inbreeding depression, genetic selection indices i.e., heritability and genetic advance and segregation pattern of F 2 population using five F 1 and their self-cross derived F 2 generations.

Analysis of variance
The analysis of variance indicate that experimental hybrids and their F 2 progenies highly differed for 50% flowering, days to 1 st harvesting, node order of 1 st flowering, plant height, Internodal length, number of fruit per plant, Fruit weight, Fruit Length and Fruit Diameter and yield.This shows the presence of considerable genetic variability among the hybrids and their F 2 progenies for further evaluation and use.

Performance study
All hybrids performed best than their F 2 progenies in respect of yield.Quality likes fruit weight, fruit length fruit diameter also deteriorated in F 2 generation.On the other side, days to harvesting, days to flowering, days to harvest, node order of fruiting, plant height and internodal length was increased in F 2 generation which clearly shows the negative effect of inbreeding.

Heritability, genetic advance and genetic advance in percentage of mean
Here h 2 (b.s) is a convenient expression of phenotypic value which serves as a guide for the breeding value of any parent.For improvement of desirable characters, heritability estimate is very essential to assess the relative effect of genotype and environment on a character in order to predict the extent of possible improvement.Therefore, heritability is one of the major indicators of response to selection for a successful breeding program.The heritability estimates above 60% are considered as high, 30% to 60% are moderate and below 30% as poor.Estimation of selection parameters (Table 3) revealed that there was a wide range of genotypic and phenotypic variances.Genotypic variance ranged from 63.09 (Plant height) to 0.01 (fruit diameter) and phenotypic variance ranged from 65.28 (Plant height) to 0.02 (fruit diameter).Comstock and Moll (1963) reported that the more diverse the environmental population the smaller the estimates of genetic variance which supports the present results of low estimates of genetic variance.The knowledge of the genotypic and phenotypic variances for each character is necessary to construct a definite selection index (Sprague, 1966).As for as the broad sense heritability estimates are concerned, Number of fruit per plant and Yield were moderately heritable, whereas, 50% flowering, days to 1 st harvest, Node order of 1 st flowering, Fruit weight, Plant height, Internodal length, Fruit length and Fruit diameter were low in heritability.The presence of non-allelic interaction played a major role in decreasing h 2 estimates for these traits.Furthermore plant height and sympodia are polygenically controlled.Cumulative environmental effects on each of these polygenes gave poor heritabilities for these traits.

Inbreeding depression
Inbreeding is a system of mating that leads to an increase in homozygosity, decline in vigor and the reduction in productivity.The degree of inbreeding in any generation is equal to the degree of homozygosity in that generation (Singh et al.,, 1990).The results for inbreeding depression for all the quantitative traits presented in Tables 6, which demonstrated that F 2 progenies suffered considerable amount of inbreeding depression.The observed depression varied from-108 to 55.19, the wide range of inbreeding depression could be explained by two factors, linkage disequilibrium and epistasis interaction.Gardner et al., (1953), Gardner (1963) andBalochet al., (1991) reported that repulsion phase linkages can cause upward or positive biases in the estimation of dominance variance in F 2 population where linkage effects are expected to be maximum.Comstock and Robinson (1948) and Soomro (2000) suggested that if multigenic epistasis were present, the epistasis of dominance will be biased down wards; ultimately the expected inbreeding depression will also go up than is observed.Inbreeding depression in polyploids has been found to exceed than what is expected by the coefficient of inbreeding.Aycock and Wilsic (1968) reported that in alfalfa, an autotetraploid, the yield decreased twice as much as predicted.This response according to them has been attributed to a decrease in favorable interactions among multiple alleles due to inbreeding and abnormal segregation at meiosis due to higher ploidy level.In present studies, however, maximum positive values for inbreeding depression were observed for yield, where F 2 values less than F 1 means.These results further suggested that in such intercultivar crosses the maximum accumulation of genes resulted in increased fertility in F 2 population, consequently resulted in the higher yield (Paul et al., 1987).

Segregation pattern
In case of segregation pattern plant height, leaf shape, pod pubescence content, peduncle shape, branching pattern and fruit color were subjected to study.Plant height and pod pubescence content are found to be polygenic trait.Fruit color showed incomplete dominance and other character expressed as Mendelian ratio.This findings are closely associated with the findings of Udengwu (2008), Abdelmageed (2010) and Kerur (2009).

Conclusions
The experiments were conducted to observe the genetic variability, inbreeding depression and segregation pattern of Okra among five commercial hybrid varieties along with a local check based on their performance, heritability and inheritance study among the varieties for improvement of yield of Okra.The experiments were carried out at the experimental farm of RHRS, Lebukhali, Patuakhali, during the period of May, 2014 to September, 2014.The results of the studies have been summarized as follows: There was significant variation among the F 1 's, their F 2 progenies and the check variety.However, all the F 1 's performed better than their respective F 2 progenies for yield and other yield contributing characters.F 1 and F 2 both generations showed low to moderate level of heritability.No of fruit per plant and Yield were moderately heritable, whereas, days to 50% flowering, days to 1 st harvesting, node order of first flowering, Fruit weight, Plant height, Internodal length, Fruit length and Fruit diameter were poor in heritability.Due to selfing the progenies become more homozygous and decline in vigor and the reduction in productivity.In case of segregation pattern plant height, leaf shape, pod pubescence content, peduncle shape, branching pattern and fruit color were subjected to study.Plant height and pod pubescence content are found to be polygenic trait.Fruit color showed incomplete dominance and other character expressed as Mendelian ratio.
EMS = Error mean square ii) Estimation of genotypic co-efficient of variation (GCV) and phenotypic co-efficient of variation (PCV) : Genotypic and phenotypic co-efficient of variation were estimated according toBurton, 1952;Singh and Chaudhury,

Figure 1 .
Figure 1.Segregation in F 2 generation for plant height in five genotype of Okra.

Figure 2 .
Figure 2. Segregation in F 2 generation for plant height in five genotype of Okra.

Figure 3 .
Figure 3. Segregation in F 2 generation for pod pubescence content in five genotypes of Okra.

Figure 4 .
Figure 4. Segregation in F2 generation for fruit base shape in five genotype of Okra.

Figure 5 .
Figure 5. Segregation in F2 generation for branching pattern in five genotype of Okra.

Figure 6 .
Figure 6.Segregation in F 2 generation for fruit color in five genotype of Okra.

Table 5 .Variance, co-variance, heritability, genetic advance and genetic advance in percentage of mean.
3.2.5.Fruit weightGenotypic (10.73%) and phenotypic (13.27%) co-efficient of variation was moderate for fruit weight in the present study.Fruit weight exhibited low heritability (17.88%) in broad sense (h 2 b ) coupled with low genetic advance in percentage of mean (3.19) (Table