Genetic variability, Heritability ... ( Gerbera jamesonii )

Results and Discussion

gerbera genotypes. High heritability was observed for all

the traits under study. Nair and Shiva (2003) and Chobe et

Mean performance, phenotypic coefficient of

al., (2010) also reported high heritability for most of the

variation (PCV), genotypic coefficient of variation

quantitative traits in gerbera. Maximum heritability was

(GCV), heritability, genetic advance and genetic gain

recorded for vase life (98.94 per cent), while, minimum

was noted for diameter of neck (8.36 per cent). High

The extent of variability with respect to eighteen

heritability showed the possibility of effective base on the

quantitative characters in nine gerbera genotypes were

phenotypic expression. Vase life is a potential character

measured in terms of mean performance, phenotypic

for selection in gerbera cultivars; the environmental

coefficient of variation (PCV), genotypic coefficient of

influence was considerable for this trait which could be

variation (GCV), heritability, genetic advance and genetic

observed from the differences between genotypic and

gain are presented in table 1. The range of variation was

phenotypic coefficient of variation. Most of the traits

high for number of flowers per sq. m per year (102.00-

indicated the dominance of additive gene effect, hence

190.00) followed by number of ray florets (52.20-81.20)

direct selection of such traits may lead to improvement of

and plant spread (33.56-57.04), respectively. Highest

quality. The minimum genetic advance was recorded in

phenotypic and genotypic variances were observed for

diameter of neck (0.10), however, the maximum genetic

number of flowers per sq. m per year (1351.02 and 1198.23)

advance was observed in number of flowers per sq. m per

followed by number of ray floret (85.70 and 80.82) and

year (67.15). A range of variation i.e 1.54 and 67.64 was

flower stalk length (53.46 and 53.24) at both the level,

recorded for diameter of neck and vase life, respectively.

respectively, whilst lowest were observed for diameter of

High heritability associated with high genetic advance

disc (0.11 and 0.09) at phenotypic and genotypic level,

proves more useful for efficient improvement of a

respectively.KaruppaiahandKumar(2011)andKavitaand

character through selection. The high heritability was

Anurbani (2010) also reported higher genotypic variation

associated with high genetic advance percentage of mean

with number of flowers per sq. m per year in African

for vase life (98.94 and 67.64) indicating the possible

marigold. The better idea can be gained by comparing the

role of additive gene action. The parallelism between the

relative amount of phenotypic and genotypic coefficient

magnitude of heritability and degree of genetic gain has

of variance for the actual strength of variability. The

been due to additive gene playing a predominant role and

estimates of phenotypic coefficient of variation were

therefore, this was more reliable for effective selection.

higher than genotypic coefficient of variation for all the

These results are in accordance with the observations

traits studied which is an indicator of additive effect of

made by Kumar and Sharma (2013) in Dendrobium

the environment on the expression of the trait. Maximum

orchids.

phenotypic coefficient of variation was observed for vase

life (33.19) followed by field life (28.45) and number of

Correlation coefficient analysis

suckers per plant per year (24.01), while, minimum was

recorded in number of leaves per plant (5.26). Genotypic

Correlation measures the degree of association between

coefficient of variance showed a range of variation

the characters. Information on correlation between the

from 2.58 to 32.01 for diameter of neck and vase life,

important economic traits are of considerable help in

respectively. Maximum genotypic coefficient of variance

the selection programme, because correlation ensures

was noticed with vase life (32.01) followed by field life

simultaneous improvement in one or two or more variables

(26.12) and number of flowers per sq. m per year (23.06).

and negative correlations bring out the need to obtain a

Burton (1952) has suggested that genetic coefficient of

compromise between the desirable traits. The analysis of

variation together with heritability estimates would give

variance revealed significant variation among all the nine

adequate information for extent of advancement through

genotypes of gerbera for all eighteen attributes (table 2

selection. A vast variation was recorded for heritability

and 3). In general, phenotypic correlations are smaller

(broad sense) in different quantitative characters of

than genotypic correlation. This could occur when genes

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