Caderno Pesquisa Bio - Volume 16-1 - TSpace

Cause and Effect Relations of Yield Components...

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CAUSE AND EFFECT RELATIONS OF YIELD COMPONENTS IN SPRING WHEAT (TRITICUM AESTIVUM L.) UNDER NORMAL CONDITIONS Waqas Manzoor Bhutta* Javaid Akhtar M. Anwar-ul-Haq Muhammad Ibrahim

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BHUTTA, W. M. et al.

teve uma correlação genotípica significante positiva, mas correlação fenotípica não significante e positiva com relação à produção de grãos, enquanto que número de espiguetas por espiga teve umas correlação não significante negativa com produção de grãos em ambos os níveis. Peso de 1000 grãos teve uma associação negativa mas significante com a produção de grãos. O coeficiente de trilha determinou que a altura das plantas, comprimento das espigas e peso de 1000 grãos são os caracteres que contribuem muito para a produção de grãos. Palavras-chave: caracteres agronômicos, trigo, correlação genotípica, análise de trilha.

ABSTRACT INTRODUCTION Ten wheat varieties / lines were sown under normal field conditions. Phenotypic and genotypic correlation among various morphological characters was estimated. Direct and indirect effects of these traits on wheat yield were determined through path coefficient analysis. Plant height and spike length had positive significant genotypic correlation but positively and non-significant phenotypic correlation with grain yields whereas, number of spikelets per spike had negatively and non-significant correlation with grain yield at both levels. 1000 grains has negative but significant association with grain yield. Path coefficient determined that plant height, spike length and 1000 grain wt are the characters which contribute largely to grain yield. Keywords: agronomic characters, wheat, genotypic correlation, path analysis.

RESUMO Dez variedades de trigo foram avaliadas em condições de campo normais e a correlação entre diversos caracteres morfológicos foi estimada. Efeito direto e indireto destes tratamentos na produção de trigo foi determinada através da análise do coeficiente de trilha. A altura da planta e o comprimento das espigas

Cereals have played a significant role in the evolution of human civilization. Wheat (Triticum aestivum) is an important food crop and a source of almost 20% of total calories of the world population. In spite of all our efforts to increase the wheat production in the country per hectare yield of wheat is much lower as compared to other developed agriculture countries. The reason for lower yield is lack of research work in this crop. Grain yield in wheat is a complex character affected directly or indirectly by every gene present in plant. Genotypic and phenotypic correlations are of value to indicate the degree to which various morpho-physiological characters are associated with economic productivity. Alam et al (1992 ). Path-coefficient analysis is one of the reliable statistical techniques which allow quantifying the interrelationship of different components and their direct and indirect effects on grain yield. Shelembi et al (1991)Through correlation estimates, the present study was conducted under normal conditions to estimate the mutual relationship of different morpho-physiological characters and also the type and extent of their contribution to yield. The information obtained may help greatly in managing and improvement of wheat breeding projects particularly in Pakistan.

MATERIAL AND METHODS

________________ * Center of Advanced Studies in Genetics & Saline Agriculture, University of Agriculture, Faisalabad-38040, Pakistan. Corresponding Author’s email address: [email protected].

The experiment was conducted in Saline Agriculture Research Centre, University of Agriculture, Faisalabad. Experimental material comprised ten

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varieties/strains of spring wheat viz LU-26S, SARC-1, SARC-2, SARC-3, SARC-4, SARC-5, SARC-6, CIM-2, CIM-31, 8721. These genotypes were sown in randomized complete block design with three repeats under normal irrigated conditions. Each plot consisted of 6 rows, each of 5 m length, for each entry, seeds were planted with the help of a rabi drill and distance between rows was kept 30 cm. At maturity one meter area of central row from each plot was marked to study the parameters on area basis and 5 guarded plants from this marked areas were tagged at random to study the different traits on individual plant basis and data were recorded for the following plant traits, plant height, spike length, number of spikelets per spike, 1000 grain wt and grain yield per plant. The data were recorded on the above mentioned five characters and subjected to variance and cross product analysis (Steel and Torrie, 1980), phenotypic and genotypic correlation coefficients between all the traits were computed according to Know and Torrie (1964). Standard errors of genotypic correlation coefficients were calculated by using the method of Reeve (1955). Direct and indirect path coefficient was calculated according to Dewey and Lu (1959).

RESULTS AND DISCUSSION Correlation In the most cases, the genotypic correlation coefficients were higher than their respective phenotypic ones. It indicates a greater contribution of the genotypic factor in association development; the observations (Table 1) indicated that in most cases, sign of phenotypic correlation coefficient was same as was of genetic correlation coefficient. A review of (table 1) indicated that plant height showed negative and nonsignificant correlation with grain yield, both phenotypic and genotypic level. These results are almost similar to the earlier findings of Deotale et al., (1991). Plant height had positive and significant correlation at genotypic level with spike length, number of spikelets and 1000 grain wt. these results are almost similar to earlier findings of Bhutta et al., (1999). Spike length showed positive and significant correlation with grain yield, 100 grain wt and number of spikelets per spike at genotypic level, while grain yield showed positive and non-significant significant correlation with phenotypic level. Similar results have also been reported by Sinha et al., (2000). A study of (Table 1) revealed positive and significant correlation between Caderno de Pesquisa Sér. Bio., Santa Cruz do Sul, v. 17, n. 1, p. 7-12, jan./jun. 2005

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number of spikelets per spike and grain yield at genotypic level but positively and non-significant at phenotypic level. The character like 1000 grain wt had positive and significant correlation with number of spikelets per spike both genotypic and phenotypic level. The estimate of genotypic correlation between 1000 grain wt and grain yield was found to be positive and significant at genotypic level then at phenotypic level. The present studies are in agreement with those of Sohran et al., (2000) Path coefficient analysis The data presented in (Table 2) revealed that direct effect of plant height on grain yield was positive indirect effects of plant height was , number of spikelets per spike, 1000 grain wt were negative, but indirect effect of plant height via spike length were positive, almost similar views have earlier been expressed by Tahira (1998). According to (Table 2) the direct effect of spike length on grain yield were positive. Indirect effects of spike length via number of spikelets per spike, 1000 grain wt were negative, whereas indirect effect via plant height was positive. Path coefficient analysis (Table 2) indicates that number of spikelets per spike had a negative direct effect on grain yield. Similarly positive values were obtained from the indirect effects through plant height and spike length, whereas 1000 grain wt had negative effect with number of spikelets per spike. Similar results had already reported by Subani (2000). The results presented in Table 2 revealed that the direct effect of 1000 grain wt on grain yield was positive. Indirect effects via plant height and spike length were negative. While indirect effects via number of spikelets per spike were positive. The findings of Alderfasi (2001) Desalegn-Debelo (2001) confirmed the present results whereas, the findings of Ahmad disagreed with the present studies. Keeping in view the results of present studies it is suggested that plant height, spike length and 1000 grain wt along with their indirect effect casual factors should be considered simultaneously as effective selection criteria for evolving yield cultivars because of their positive contribution to grain yield.

REFERENCES ALAM, K.; SHABBIR, G.; CHOWDHRY, M. A.; KHALIQ, I. 1992. Correlation of post-emergence charcters with yield in bread wheat. Pak. j Agri .Sci., 29: 449Caderno de Pesquisa Sér. Bio., Santa Cruz do Sul, v. 17, n. 1, p. 7-12, jan./jun. 2005


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452 . ALDERFASI, A. A. 2001. Evaluation of certain traits association with drought resistance in wheat under field condition. Ann. Agri. Sci. Cairo. 46(1): 71-83.

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Table 1 - Genotypic and phenotypic correlation coefficients between yield and other traits Traits

BHUTTA, W. M.; CHOWDHRY, M. A. 1999. Association analysis of some drought related traits in spring wheat. JAPS. 9(1-2): 77-80.

1 r ( g) r( p) 2 r ( g) r( p) 3 r ( g) r( p) 4 r ( g) r( p) 5 r ( g) r( p)

DEOTALE, R. D.; SORTE, N. V.; DAWANDE, V. B. 1991. Grain yield relationship with some morpho-physiological traits in wheat (Triticum aestivum L.) J. Soils Crop. 1: 83-85. Desalegn-Debelo, Bedada-Girma, Zewdie-Alemayehes, Gelalcha-S. 2001. Drought tolerance of some bread wheat genotype in Ethiopia. African Crop Sci. J. 9 (2): 385-392. DEWEY, D. R.; LU, R. H. 1959. A correlation and path coefficient analysis of components of crested wheat grass production. Agron. J. 51:515-518. KWON, S. H.; TORRIE, J. H. 1964. Heritability and interrelationship among traits of two soybean populations. Crop Sci. 4:196-198. NABI ,T. G.; CHOWDHRY, M. A.; AZIZ, K.; BHUTTA, W. M. 1998. Interrelation ship among some polygenic traits in hexaploid spring wheat (Tricum aestivum L.). Pak. J. Biol. Sci. 1(4):299-302. REEVE, E. C. R. 1955. The variance of the genetic correlation coefficients. Biometrics. 11:357-374.


Plant height 1 1

Spike length 0.2827* 0.2275

No. of 1000 grain Grain yield spikelets weight 0.047 -0.269 -0.0765 0.128 -0.268 -0.0498 -0.126 -0.639* 0.511** -0.009 -0.4935 0.294 1 0.0889 0.297* 1 -0.0684 0.295* 1 0.031 1 0.014 1 1

Table 2 - Direct and indirect effect matrix (dependentable variable is grain yield) Traits Plant height Spike length No Spikelets per plant 1000 grain weight Grain yield

Plant height 0.076 0.035 0.004 -0.03 -0.022

0.055 0.119

No. of spikelets per plant -0.008 -0.114

1000 grain weight -0.041 -0.097

0.083 -0.075 0.067

-0.165 0.014 0.011

-0.014 0.152 -0.063

Spike length

Grain yield -0.036 0.294 -0.036 -0.218 0.519

STEEL, R. G. D.; TORIE, J. H. 1980. Principles and Procedures of Statistical Analysis. 2nd Ed. McGraw Hill Book Co. Inc. NY. USA. SUBANI, G. M.; CHOWDHRY, M. A. 2000. Correlation and Path-Coefficient analysis in bread wheat under stress and normal condition. Pak. J. Biol. Sci. 3 (1):72-77. SHELEMBI, M.A.; WRIGHT, W. T. 1991 . Correlation and path – coefficient analysis on yield components of twenty spring bread wheat genotypes evaluated at two location in Arasha region of Tanzania . In Seventh Regional Wheat Workshop for Eastern, Central and Southern AFRICA, Nakurn, Kenya 16-19 Sept . 1991.

