Study of Trait Alliance with Grain yield , Its Attributes of Different Land Races of Maize ( Zea Mays L . )

Introduction Maize (Zea mays L.; 2n=20) is one of the most important economic cereal crops of the world. It was domesticated over the past 10,000 years from the grass teosinte in Central America1and has been subject to cultivation and selection ever since. It ranks one of the three important cereal crops in Abstract The research was carried out to study the correlation and path coefficient analysis of 51different land races of maize for yield and component traits. Analysis of correlation between different characters suggested that the value of genotypic correlation were some what higher as compared to their corresponding phenotypic correlations signified the inherent relationship among the characters. Grain yield kg per ha. showed significant positive association with days to 50% pollen shed, days to 50% silking, days to 75% dry husk, number of cobs per plot, cob weight per plot and shalling perportion at both genotypic and phenotypic levels. Path co-efficient analysis revealed that the maximum positive direct effects of cob weight per plot, shelling perportion, ear height and number of cobs per plot towards grain yield. This finding suggested that more emphasis should be given to number of cobs per plot, cob weight per plot and shalling perportion in selection programmes aiming to improve grain yield in maize. ARTICLe hISTORy

poultry.It is also a source of industrial raw material for the production of flour, flakes, corn starch, corn oil, corn syrup, glucose, alcohol, ethanol, gluten, dextrose, custard powder and many more products, besides these, it's also used for making glue, soaps, insecticides, toothpaste, shaving cream, rubber tires, rayon, model plastic, etc., 2 .With the introduction of hybrids in maize, the inclinations of acreage and  production have been an increasing due to its high yield potential.In India, it is grown round the year in an area of 9.43 million hectares with the production of 21.81 million tonnes and 2509 kg/ha productivity, whereas, in Gujarat, it covers an area of 0.39 million hectares with a total production of 0.57 million tonnes with 1478 kg/ha productivity 3 .
Due to complex nature of yield direct selction based on per se performance may not effective, in such case indierect selection for yield attributes with high heritability estimates will be more effective.Genotypic correlation had been considered as a effective tool to investigate the interrelationship among agronomic traits in genetically diverse population 4 .The study of correlation alone is not enough to provide of related importance of direct or indirect influences of each of the component characters on seed yield.In this context, path co-efficient analysis is an important tool for plant breeders in partitioning the genotypic correlation co-efficient into the direct and indirect effects of independent variables on the dependant variable i.e., kernal yield.Information on character association in crop is important for effective and rapid selection in crop breeding 5 .Thus the objective of present study was to know the relationship between kernel yield and yield contributing characters, hence correlation co-efficient of these yield attributing characters with kenal yield and to utilize these parameters i.e. correlation coefficient and path analysis for further improvement in available germ plasm of land races.

Material and Methods
The experiment was carried out to evaluate51 different land races of maize.  and elaborated by 10 .

Result and Discussion
Yield is a complex character and it is multiplicative end product of other quantitative traits as components of the yield 11 .Hence, the selection of superior genotypes based on yield as such would not be more valuable, but several yield attributes have to be handled together.Improvement in yield potential would be more reliable, if indirect selection is made based on the traits correlated with yield.Thus, for rational improvement of yield and its components, the understanding of correlation of yield with different yield contributing characters has been very useful.This association should be at genotypic level by eliminating the environmental influence from the phenotypic values.
The analysis of variance revealed the existence of considerable genetic differences among the genotypes for all the traits (Table 1).This indicated suitability of experimental material for estimation of genetic parameters.In general the values for genotypic correlation were slightly higher than their phenotypic counterparts.This indicated that though there was a high degree of association between two variables at genotypic levels, but its phenotypic expression was deflated by the influence of environment.All the traits except 100-seed weight showed positive correlation with grain yield at both genotypic and phenotypic levels.Characters, days to 50% pollen shed, days to 50% silking, days to 75% dry husk, cob weight per plot and shelling perportion showed significant positive correlation co-efficient at phenotypic level (Table2).Such positive interrelationship between grain yield and its attributes have also been reported in maize by several researchers i.e., 12,13,14,15,16,17.Thus, these attributes were more influencing the grain yield in maize and they can serve as important yield contributing traits for improvement in grain yield.
Days to 50% silking (r g =0.340), plant height (r g =0.572, r p =0.244), ear height (r g =0.382, r p =0.283), and shelling per cent (r g = 1.160, r p =0.296) at genotypic level as well as well as phenotypic level except days to 50% silking exhibited significantly positive correlation with the number of cobs per plot.The association of 100-seed weight with number of cobs per plot (r g = -0.224)was significantly negative at genotypic level.
The ear height had significant positive correlation with plant height (r g = 0.915, r p = 0.847) at both genotypic level as well as phenotypic level, where as days to 75% dry husk had remain significant negative correlation with plant height (r g = -0.387,r p = -0.296)at both genotypic level as well as phenotypic level (Table 2).
In order to achieve a clear picture of interrelationship of various component characters with grain yield at genotypic level, direct and indirect effects of various characters on grain yield were calculated using path co-efficient analysis (Table 3).Path co-efficient analysis, ninetraits were considered as causal variable of grain yield.It was observed that considerable positive direct effects on grain yield were caused by cob weight per plot, shelling perportion, ear height and number of cobs per plot (Fig. 1).These characters were thus important yield contributing traits in the present population of land races.The direct positive effects on grain yield were important in path co-efficient analyses carried out in maize by 16,18,19 .The residual effect was in the range of low to moderate (0.136), which indicates that there are some more character which contribute to the grain yield which need to be further study.
Among traits studied, the cob weight per plot is of more importance because; it showed the highest positive direct effect on grain yield along with significant correlation co-efficient (Table 3).Thus cob weight per plot should be the vital tool for increasing grain yield in the present population.This trait may be an important feature of an ideal plant type in maize.
Overall picture of path analysis in the this study revealed that selection through cob weight per plot, shelling perportion, ear height and number of cobs per plot may bring positive contribution to grain yield.Hence, it would be rewarding to lay more emphasis on these traits in selection programme for improvement of grain yield.Though the direct effect of test weight and days to 50% silking was not very high, but these traits affected the yield positively and indirectly through other traits.While different traits like days to 50% pollen shed, days to 75% husk and plant height had negative direct effect on seed yield indicating their limited role in yield improvement.

Table 1 : Analysis of variance (ANOVA) showing mean squares of different traitsin maize Source of d.f. Days to
*,** Significant at 5 % and 1%level respectively

Table 3 : Path co-efficient analysis showing direct and indirect effects of nine causal traits on grain yield in maize Characters Days to Days Days Plant ear Number Cob wt. 100-Shelling Genotypic 50% Po-to 50% to 75% height height of Cobs per Plo seed (%) Correlation wi- llen shed Silking Dry husk (cm
*, ** Significant at P = 5 and 1 per cent levels, respectively.Note : 1. Bold diagonal values indicates direct effect.Residual effect = 0.136