Heritability analysis to screen elite sugarcane ( Saccharum spp . ) soma clones under field condition

Three elite sugarcane varieties were used in this experiment to check the heritability parameters which consist of range, environmental variance, genetic variance, genetic advance and broad sense heritability. Four hundred and five soma clones were observed for phenotypic characters including number of tillers (plant -1 ), cane height (cm), number of internode (plant -1 ) and width of internode (cm). Variability range for different characters include number of tillers (plant -1 ), cane height (cm), number of internode (plant -1 ) and width of internode (cm) and were also assessed for three auxins. Highest heritability and remarkable genetic advance were recorded for the height of the cane and number of internode (plant -1 ) was found when 2, 4-D was applied in Murashige and Skoog (MS) media, which directly affected the yield of sugarcane. High heritability and good genetic advance were observed for number of tillers (plant -1 ) and width of internode (cm) when NAA was applied in the media. In addition to this, increasing concentration of hormones had positive effect on the heritability and genetic advance for phenotypic traits of the sugarcane soma clones. Similarly, it was observed that environmental and genetic variances have optimum effect on the heritability of the sugarcane. Application of 2, 4D and picloram were recorded as efficient in transference of high heritability and genetic advance to them. On the basis of higher heritability selection made to develop hybrid in sugarcane, higher genetic advancement helped to develop synthetic varieties in sugarcane.

Three elite sugarcane varieties were used in this experiment to check the heritability parameters which consist of range, environmental variance, genetic variance, genetic advance and broad sense heritability.Four hundred and five soma clones were observed for phenotypic characters including number of tillers (plant -1 ), cane height (cm), number of internode (plant -1 ) and width of internode (cm).Variability range for different characters include number of tillers (plant -1 ), cane height (cm), number of internode (plant -1 ) and width of internode (cm) and were also assessed for three auxins.Highest heritability and remarkable genetic advance were recorded for the height of the cane and number of internode (plant -1 ) was found when 2, 4-D was applied in Murashige and Skoog (MS) media, which directly affected the yield of sugarcane.High heritability and good genetic advance were observed for number of tillers (plant INTRODUCTION Sugarcane (Saccharum spp.) hybrids is an important cash crop which belongs to the Poaceae family (Sharma, 2005;Cha-um et al., 2006).Knowledge of the heritability of any phenotypic traits will be very helpful in breeding programs worldwide.So, genetic variability and heritability of sugarcane (Parfitt, 2000;Kimbeng et al., 2002;Janghir et al., 2013;Glaz and Kang, 2008;Qamar et al., 2015).The relationship between the characters is difficult to understand mostly when low heritability occurs (Bakhsh et al., 2006;Silva et al., 2007).Selection of the characters was directly made by understanding the nature of one trait affected by the other (Ali et al., 2013Butt et al., 2015;Jackson, 1994;Tyagi and Khan, 2010).Phenotypic character has association with the yield components (Jamoza et al., 2013) like number of stalk (plant -1 ), width of cane (cm), and height of cane (cm) which are helpful for the variety development (Tyagi and Khan, 2010).The function of heritability in genetics was considered to evaluate quantitative traits and qualitative traits which are valuable for economic and used for the breeding programs.Heritability estimation (Hanson et al., 1956) together with genetic advance are most important for selection of yield, and its contributing characters are useful for future selection of superior clones in sugarcane industry (Ahmed et al., 2012).The improvement of characters will depend mostly on the extents of genetic variability in the base population and heritability.Therefore, the present study is helpful for the assessment of heritability parameters of phenotypic characters like number of tillers (plant -1 ), number of internodes (plant -1 ), height of cane (cm) and width of internode (cm).There are many traits which are important for the heritability enhancement, but few are optimized under field condition including those traits that are vital for the selection of character which can be utilized for further improvement of the yield of sugarcane.

MATERIALS AND METHODS
Established plants were transferred to the field from pots for further heritability analysis.Data was recorded for four hundred and five replicates (405) of sugarcane.

Assessments of phenotypic traits
Only 135 stable soma clones were finally evaluated for four phenotypic characters related to yield.

Number of tillers (plant -1 )
Three randomly selected canes were recorded for the number of tillers from each treatment.Thereafter, their average was noted.

Height of cane (cm)
The height of each selected plant was calculated in centimeters from the surface of soil to the tip of the leaf.

Width of internode (cm)
The stem girth of each plant was recorded in centimeters by vernier Solangi et al. 169 caliper, from bottom, mid and top portion and average of the three data was used for data analysis.

Number of internodes (plant -1 )
Three randomly selected canes from each treatment were counted for number of internode.Thereafter, their average was noted.

Heritability analysis
Data was statistically analyzed by using Steel et al. (1997)

Heritability analysis in soma clones of NIA-2012
The results of parents and soma clones for heritability are presented in Tables 1, 2 and 3 ) (45%), and width of internode (cm) (52) was recorded in picloram.As number of tillers (plant -1 ) ranged from 1 to 6, height of cane (cm) ranged from 109.12 to 119.15.Whereas, number of internode (plant -1 ) ranged from 7 to 17 and width of internode (cm) ranged from 1.11 to 1.65 in NAA.Low heritability for number of tillers (plant -1 ) (19%), height of cane (37%), number of internode (47%) and width of internode (cm) (53%) was recorded in NIA-2012.In case of NIA-2012 2, 4-D was the best hormone among tested auxins as it resulted in high genetic vitiations for height of cane (cm), number of internode (plant -1 ), moderate for width of internode (cm) and poor for number of tillers (plant -1 ) followed by picloram that induced moderate genetic variations for height of cane and width of internode.

Heritability analysis in soma clones of NIA-105
The data of parents and soma clones for heritability are depicted in Tables 4, 5, 6 and 7 number of tillers (plant -1 ) ranged from 1 to 9 and height of cane (cm) from 111.19 to 126.14.While number of internode (plant -1 ) ranged from 10 to 28 and width of internode (cm) ranged from 1.13 to 2.34 in 2, 4-D.High heritability for number of internode (plant -1 ) (83%) with considerable genetic advance (4.95) was observed in NIA-105 while moderate heritability (58%) with less genetic advance (0.33) was recorded for width of internode whereas, low heritability for number of tillers (plant -1 ) and height of cane were revealed with reduced genetic advance.While as number ), height of cane and width of internode was obtained in NAA.In case of NIA-105 2, 4-D ), moderate for width of internode and poor for number of tillers (plant -1 ) followed by picloram that induced moderate genetic variations for height of cane and width of internode.

Heritability analysis in soma clones of Gulabi-95
The results of parents and soma clones for heritability are compiled in Tables 7, 8 and 9 ) ranged from 12 to 28 and width of internode ranged from 1.13 to 2.54 in 2,4-D.Whereas, low heritability for number of tillers (plant -1 ) (30%), height of cane (24%) and width of internode (50%) with less genetic advance was found in Gulabi-95.Low heritability for number of internode (plant -1 ) (44) with remarkable genetic advance (4.09) was recorded in 2, 4-D.While as number of tillers (plant -1 ) ranged 1 to 9, height of cane (cm) from 108.24 to 127.18.Whereas number of internode ranged from 10 to 28 and width of internode ranged from 1.18 to 2.34 in picloram.Moderate heritability for number of internode (plant -1 ) (61%) with good genetic advance (4.05) was found in Gulabi-95.Moderate heritability for width of internode (67%) with low genetic advance (0.433) was recorded in Gulabi-95.Whereas low heritability for number of tillers (plant -1 ) (48%), height of cane (cm) (37%) and with less genetic advance was obtained in Gulabi-95.Number of tillers (plant -1 ) ranged from 2 to 8, height of cane from 118.12 to 127.16.While number of internode (plant -1 ) ranged from 10 to 26 and width of internode ranged from 1.11 to 2.24 in NAA.High heritability for number of internode (plant -1 ) (77%) with good genetic advance (4.94) was found in Gulabi-95.Whereas low heritability for number of tillers (plant -1 ) (47%), height of cane (51%) and width of internode (51) with less genetic advance was obtained in Gulabi-95 when NAA was applied.For Gulabi-95 × somaclones 2,4-D do not stimulate genetic variation rather Picloram and NAA generated moderate genetic variations for number and width (plant -1 ) of internode and number of tillers (plant -1 ) while low variations for height of cane.

Heritability exploration in NIA-2012
High heritability coupled with good genetic advance and high environmental variance in NIA-2012 × soma clones for height is also reported earlier in some other varieties of sugarcane all around the world (Zhou et al., 2005(Zhou et al., , 2011)).The results indicate existence of considerable genetic vitiations induced through callus culture.Moderate heritability with poor genetic advance for number of tillers (plant -1 ) and number of internode (plant -1 ) was consistent with the findings of Khan et al. (2009) and Raza et al. (2014).High heritability with low genetic advance and environmental effects found for thickness of cane is supported by Hoy et al. (2003) who observed smaller cane diameter in the plants regenerated from callus culture.Generally width of internode (cm) is negatively correlated with yield of sucrose (Pandey, 1989;Butterfield and Nuss, 2002) therefore low genetic advance for this character is in favor of the present genetic improvement strategy.It can be inferred from over all heritability analysis that 2, 4-D and picloram are effective among tested auxins towards soma clonal variation as compared to NAA.

Heritability exploration in NIA-105
Good genetic advance and high heritability coupled with and low environmental variance for number of internode (plant -1 ) is supported by the work of Bull (2000) and who also elaborated environmental effect on number of internode (plant -1 ) directly correlated to the yield of sugarcane.It is obvious from results that this character is largely influenced by growth hormones not by environmental effects so selection for improvement of that characters must be useful.High heritability with low genetic advance was recorded for width of internode (cm) indicating non-additive effect of gene.Similar results of higher number of internodes, greater length of internodes contributing height of cane and smaller width of cane (cm) was also reported by Sood et al. (2006).Low heritability with less genetic advance and environmental variance for number of tillers is also reported by many workers dealing with same type of auxins (Sani and Mustapha, 2010;Ahmed et al., 2012;Riaz et al., 2016).It can be inferred from overall heritability analysis of NIA-105 × soma clones that more genetic changes were induced by 2,4-D followed by NAA, than Picloram.

Heritability exploration in Gulabi-95
It is evident from the result that moderate heritability with fine genetic advance and high environmental variance for number of internode (plant -1 ) selection of that character is possible for further improvement.Low heritability coupled with less genetic advance for number of tillers (plant -1 ) was recorded in clones of Gulabi-95 parents.Moderate heritability with low genetic advance for number of height of cane (cm) (high environmental effect) in picloram showed that this character was selected for future advancement of this phenotypic character.Similar results are consistent with Rajeswari et al. (2009).The results suggest increasing the duration and numbering of subcultures to get high genetic advance for number of internode (plant -1 ) and number of tillers (plant -1 ) before the selection of soma clones as a new cultivar.It can be inferred from over all heritability analysis in Gulabi-95 × soma clones that more genetic changes were induced by Picloram and NAA, respectively in spite of 2,4-D.

Conclusion
Increasing concentration of hormones in the MS (media) Solangi et al. 173 has positive effect on the broad sense heritability.Genetic advance of sugarcane soma clones for phenotypic traits was improved.Although effect of each auxin on the heritability of sugarcane is variety dependent but 2, 4-D, the only general growth hormone, created remarkable genetic variation in the progeny of the sugarcane.Standardization of the type of auxin must be made for each genotype separately for heritability analysis and for better result.Besides heritability, environmental variance play important role in the phenotype character of the sugarcane varieties.
analysis of variance technique.Phenotypic traits were further subjected to heritability analysis.Genetic parameters viz., heritability percentage in broad sense (h 2 b.s), environmental variance (Ve), genetic variance (Vg) and genetic advance (G.A) were calculated as suggested by Falconer and Mackay (1996percentage in broad sense (h 2 b.s %) = Vg / VC3 x 100 8. Genetic advance (G A) = K × (H) × SD.Where, V = variance C3 third sub culture generation, and p = parent.S.D = Phenotypic standard deviation K = Constant (2.06) for selection difference at 5% Selection intensity Ve = Environmental variance Vg = Genetic variance H = Heritability coefficient Vp1 = Variance of parent one Vp2 = Variance of parent two VC3 = Variance of C3 soma clones h 2 % (b.s) = Heritability percentage in broad sense (GA) = K × (H) × SD N = number of replication . Overall variations were observed among soma clones and their parents as a response of varying auxins applied.Number of tillers (plant -1) ranged from 2 to 9, height of cane from 111.23 to 127.87.While number of internode (plant -1

Table 1 .
Heritability analysis of sugarcane parental genotype (NIA2012) and their soma clones affected by different concentrations of 2, 4-D.
. Overall variations were observed among soma clones and their parents as a response of different auxins applied.Differential heritability and genetic advance was observed in tested parents and their soma clones.Number of tillers ranged from 1 to 8.5 and height of cane from 110.19 to 126.19.While number of internode ranged from 10 to 24 and width of internode ranged from 1.11 to 1.94 in 2,4-D.High heritability for height of cane (77%) with remarkable genetic advance (8.6) was observed in NIA-2012 while

Table 2 .
Heritability analysis of sugarcane parental genotype (NIA2012) and their soma clones affected by different concentrations of Picloram.

Table 3 .
Heritability analysis of sugarcane parental genotype (NIA2012) and their soma clones affected by different concentrations of NAA.

Table 4 .
Heritability analysis of sugarcane parental genotype (NIA-105) and their soma clones affected by different concentrations of 2, 4-D.

Table 5 .
Heritability analysis of sugarcane parental genotype (NIA-105) and their soma clonesaffected by different concentrations of Picloram.

Table 6 .
Heritability analysis of sugarcane parental genotype and their (NIA-105) soma clones affected by different concentration NAA.

Table 8 .
Heritability analysis of sugarcane parental genotype (Gulabi-95) and their somaclones affected by different concentrations of Picloram.

Table 9 .
Heritability analysis of sugarcane parental genotype (Gulabi-95) and their soma clones affected by different concentrations of NAA.