Character Association and Path Coefficient Analysis for Yield Component Traits in Rice (Oryza sativa L.) Under Moisture Stress Condition at Vegetative Stage
Chandrashekhar Haradari* and Shailaja Hittalmani
Department of Genetics and Plant Breeding, India
Submission: February 02, 2017; Published: March 27, 2017
*Corresponding author: Chandrashekhar Haradari, Department of Genetics and Plant Breeding, UAS, Bangalore, 560 065, Karnataka, India, Email: chandhugpb@gmail.com
How to cite this article: Chandrashekhar H, Shailaja H. Character Association and Path Coefficient Analysis for Yield Component Traits in Rice (Oryza sativa L.) Under Moisture Stress Condition at Vegetative Stage. Curr Trends Biomedical Eng & Biosci. 2017; 2(5): 555597. DOI: 10.19080/CTBEB.2017.02.555597
Abstract
Present study was attempted with forty six F3 families to trace the associations among twelve yield component characters under moisture stress condition at vegetative growth stage in rice during 2013. Grain yield per plant showed significant positive association with productive tillers per plant, filled spikelet per panicle and harvest index and significant negative association with days to flowering and days to maturity at both genotypic (rg) and phenotypic (rp) levels. Path coefficient analysis exhibited the positive direct effect on grain yield per plant via days to flowering, productive tillers per plant, spikelet fertility and 100 grain weight. In total, four characters viz., productive tillers per plant, filled spikelets per panicle, spikelet fertility and harvest index showed highly significant positive correlation coefficients along with high direct effects on grain yield per plant indicating selection based on these characters could be very effective in selecting high yielding genotypes under moisture stress condition at vegetative stage stress in rice.
Keywords: Correlation; Moisture stress; Vegetative stage; Grain yield; Rices
Introduction
In grass family, Rice (Oryza sativa L.) is the most important staple food crop for more than half of the world's population [1]. In India, rice is cultivated on 44.00 million hectares of area with a production of 103.00 million tons and productivity of 2.34 t/ ha [2-4]. Rice is cultivated in diverse agro-ecosystems viz., rainfed lowland, and flood prone, upland, irrigated and aerobic conditions. Dynamics in climatic factors brought water scarcity to rice cultivation which led to reduction in the production.
Grain yield is the ultimate criterion which a plant breeder always keep in mind, while developing new variety with high yield potential. However, while carrying out selection for a highly variable character like grain yield, straight selection may not always be efficient since it is a polygenic character largely influenced by environment? In any yield improvement program, knowledge of associations between yield and its component characters is very essential. Hence, the investigation was carried out with the objective to study associations between yield and yield component characters which will be useful in formulating selection criteria for high yielding genotypes in rice crop improvement programmer.
Materials and Method
Experimental location and material used
Current study was conducted at K block, Department of Genetics and Plant Breeding, University of Agricultural Sciences, GKVK, Bengaluru-560 065, Karnataka, India (12o 58' North latitude, 77° 35' East longitude and 930 meter above mean sea level) during 2013. Experimental plant material considered in the study includes 46 F3 families of rice derived from the cross RB6xQRT25. The parental line RB6 (sensitive to moisture stress), a recombinant inbred line derived from RpBio*BL122 and QRT25 (tolerant to moisture stress), a near isogonics line derived from IR64*Azucena were used to develop F3 families.
Experimental layout and Statistical analysis
Plant material was planted with a spacing of 20cmx20 cm in a randomized complete block design with two replications and evaluated for grain yield and yield component characters under moisture stress condition at peak vegetative growth stage. Moisture stress was imposed at vegetative stage of crop growth for a period of 15 days (from 61 to 75 days after sowing)by withholding irrigation and preventing rain water using a rainout-shelter.
Observations were recorded on 10 randomly selected plants per family in both the replications on 12 yield component characters viz., PHT-plant height (cm), DF-days to flowering, DM-days to maturity, PT-productive tillers per plant, PL-panicle length (cm), PE-panicle exsertion (cm), FS-filled spikelet per panicle, SF-spikelet fertility (%), 100GW-100 grain weight (g), BM-biomass per plant (g) and HI-harvest index (%) along with GYLD-grain yield per plant (g) by following IRRI standard evaluation system. The recommended package of practice (UAS, Bangalore, India) was followed to raise a good crop of rice under moisture stress condition at peak vegetative growth stage.
Data analysis of each character was carried out using mean values of 10 randomly selected plants from each family in each replication. Correlation coefficients between all pairs of characters were determined using the method suggested by Webber & Moorthy [5], and then were compared with 'r' values given by Snedecor [6] at (n-2) degrees of freedom at the probability levels of 0.05 and 0.01 to test their significance. Path coefficient analysis was carried out as suggested by Wright [7] and illustrated by Dewey and Lu [8], which unveils the direct and indirect effects of different component characters on grain yield per plant.
Results and Discussion
Correlation coefficient analysis among yield and yield component characters
* and ** = Significant at 5 % and 1 % respectively.
* and ** = Significant at 5 % and 1 % respectively.
Genotypic and phenotypic correlation coefficients between different pairs of yield and yield component characters are presented in Table 1 & 2 respectively. Grain yield per plant showed significant positive association with productive tillers per plant (rg=0.35, rp=0.46), filled spikelet per panicle (0.64, 0.32) and harvest index (0.97, 0.57) at both genotypic (rg) and phenotypic (rp) levels. However, grain yield per plant exhibited significant negative association with days to flowering (rg= -0.67, rp= -0.29) and days to maturity (0.88, 0.32) at both genotypic and phenotypic levels. In most of the cases, estimates of genotypic correlation coefficients were higher than the corresponding phenotypic correlation coefficients indicating suppression of environment effect on the characters and could be used as surrogates for selection of genotypes with high grain yield. Earlier studies by Saimuraliraj [9], Gireesha [10] and Haider, et al. [11] were reported similar findings of significant positive association of productive tillers per plant and harvest index on grain yield, both at phenotypic and genotypic levels under moisture stress conditions. While, Pantuwan et al. [12] in a study observed a significant negative association of grain yield with days to flowering both at genotypic and phenotypic levels.
Path coefficients analysis of yield component characters on grain yield
Residual effect: 0.09, Where, ‘rg’ - Genotypic correlation coefficient, ‘rp’- Phenotypic correlation coefficient.
Path coefficient analysis (Table 3) revealed that the positive direct effect on grain yield per plant was exhibited by days to flowering (0.107), productive tillers per plant (0.089), spikelet fertility (0.012) and 100 grain weight (0.038). The findings are in agreement with the earlier studies in rice by Manickavelu et al. [13] & Basavaraj et al. [14]. Among the yield component characters, four characters viz., productive tillers per plant, filled spikelets per panicle, spikelet fertility and harvest index showed highly significant positive correlation coefficients along with high direct effects on grain yield per plant indicating selection based on these characters could be very effective for the improvement of grain yield under moisture stress condition at vegetative stage stress in rice [15].
Conclusion
Present study isolated four characters viz., productive tillers per plant, filled spikelets per panicle, spikelet fertility and harvest index out of twelve yield component characters studied which are ideal to consider in a selection strategy for selection of genotypes with high grain yield under moisture stress situation at vegetative stage in rice.
Acknowledgement
We would like to thank MASLAB, Department of Genetics and Plant Breeding, UAS, Bangalore, India for the facilities provided in conducting the research experiments and Kirkhouse Trust, United Kingdom for their financial support followed by scientific advice throughout the course of study.
References
- Bernier J, Atlin GN, Serraj R, Kumar A, Spaner D (2008) Breeding upland rice for drought resistance. J Sci Food Agric 88(6): 927-939.
- Kumar A, Rangare NR, Vidyakar V (2013) Study of genetic variability of indian and exotic rice germplasm in Allahabad agroclimate. The Bioscan 8(4): 1445-1451.
- Viraktamath BC, Ramesha MS, Hari Prasad AS, Senguttuvel P, Revathi P, et al. (2012) Two decades of hybrid rice research and development in india in ddr Technical Bulletin No:66/2012.
- Li J, Zhang H, Wang D, Tang B, Chen C, et al. ( 2011) Rice omics and biotechnology in china. POJ 4(6): 302-317. Kahani , F Hittalmani S (2016) Identification of F2 and F3 segregants of fifteen rice crosses suitable for cultivation under aerobic situation. SABRAO J Breed Gen 48(2): 219-229.
- Webber CR, Moorthy BR (1952) Heritable and non- heritable relationship and variability of content and agronomic characters in the segregation of soybean cross. Agron J 4: 202-209.
- Snedecor GW (1961) Statistical methods. The Iowa State University Press, Acer, Iowa, USA.
- Wright S (1921) Correlation and causation. J Agric Res 20: 557-585.
- Dewey DR, Lu KH (1959) A path analysis of crested grass seed production. Agron J 51(9): 515-518.
- Saimuraliraj (1992) 6 x 6 F2 diallel analysis in fine grained rice (Oryza sativa L) M.Sc. (Agri.) Thesis, Univ. Agric Sci Bangalore pp. 150.
- Gireesha TM (1999) Genetic investigations on root morphological characters in recombinant inbred lines and crosses in rice (Oryza sativa L.). M. Sc. (Agri) thesis Univ Agril Sci Bangalore p. 77.
- Haider Z, Khan AS, Zia S (2012) Correlation and path coefficient analysis of yield components in rice (Oryza sativa L.) under simulated drought stress condition. Amer-Eurasian J Agric & Environ Sci 12(1): 100-104.
- Pantuwan G, Fukai S, Cooper M, Rajatasereekul S, O'Toole JC (2002) Yield response of rice (Oryza sativa L.) genotypes to different types of drought under rainfed lowlands 2. Selection of drought resistant genotypes. Field Crop Res 73: 169-180.
- Manickavelu A, Nadarajan N, Ganesh SK, Gnanamalar RP, Babu R C (2006) Drought tolerance in rice: morphological and molecular genetics consideration. Plant Growth Regul 50(2): 121-138.
- Basavaraja T, Gangaprasad S, DhusyanthaKumar BM, Hittlamani S (2011) Correlation and path analysis of yield and yield attributes in local rice cultivars (Oryza sativa L.). Electron J Plant Breed 2(4): 523526.
- IRRI (1996) Standard evaluation system for rice. (4th edn,). Pp.17-18.