| Correlation, multiple correlation and path coefficient
analysis of yield components in wheat (Triticum aestivum L.) M.B. KUMBHAR, M.M. RAJPUR, A.J. MALIK and N.N. ANSARI. Department of Plant Breeding and Genetics Sind Agriculture University, Tandojam, Pakistan. The knowledge of interrelationships of factors influencing yield which is a complex phenomenon, is a prerequisite for designing an effective plant breeding programme (WORLEY et al. 1976). Although information about the correlation of agronomic and morphological characters with yield is helpful in the identification of the components of this complex character, yet, these do not provide precise information on the relative importance of direct and indirect influences of each of the componential character (LARIK 1978). With increasing number of variables it becomes necessary to measure the contribution of these variables to the observed correlation and hence partition the correlation coefficients into components of of direct and indirect influence (PANDEWY & GITTON 1975). Path coefficient analysis provides an effective means of partitioning correlation coefficients into unidirectional pathway and alternate pathways. This analysis thus permits a critical examination of specific factors that produce a given correlation and could be successfully employed in formulating an effective selection strategy. This technique has been extensively used by conventional breeders (BHATT 1973; LYRENE & SHANDS 1975). The present study with a wheat variety 6591 was therefore conducted to provide information on interrelationship of grain yield with some important yield components and partition the observed phenotypic correlations into their direct and indirect effects in order to identify characters of utmost importance which may be used as selection criteria in a wheat breeding programme. Simple correlation coefficient (r) and regression coefficient (b) were calculated after SNEDECOR (1956) and multiple correlation was calculated by using the formulae of STEEL & TORRlE (1960). Phenotypic correlations were partitioned into path coefficient using the technique outlined by DEWEY & LU (1959). This technique involves partitioning of correlation coefficient to determine direct (unidirectional path-ways ('P') and indirect influence through alternate pathways (Pathway 'P'x correlation coefficient 'r) of various variables over grain yield per plant. Grain yield was considered as the resultant variable and the others as causal variables. Results and Discussion Simple correlation coefficient (phenotypic) between all possible combinations were estimated (Table 1). Results reveal that all the characters exhibited a strong positive correlation (P>=.01) with their possible combinations. The correlations reported by BHATT (1973). VARIK & VERMA (1972) and LARIK (1978) also reveal similar associations. This indicated that selection for these characters can be effective in the search of high yielding wheat varieties. |
| --> Next |