Correlation and path coefficient analysis in Giant Taro (Alocasia macrorrhiza L.)

Available online at www.banglajol.info Bangladesh J. Sci. Ind. Res. 50(2), 117-122, 2015 Correlation and path coefficient analysis in Giant Taro (Alocasia macrorrhiza L.) K. K. Paul1*, M. A. Bari1 and S. C. Debnath1 1 Institute of Biological Sciences, Rajshahi University, Rajshahi - 6205, Bangladesh. Abstract Genotypic and phenotypic character associations as well as direct and indirect effects were estimated for eleven characters such as plant height, petiole length, petiole breadth, leaf area index, inflorescence length, spathe length, spathe breadth, corm length, corm breadth, corm weight and yield per plant, in giant taro (Alocasia macrorrhiza L). The results revealed that plant height, LAI, corm length, corm breadth, had positive correlation with yield per plant both at genotypic and phenotypic level. Relatively higher positive and direct effect was found through petiole length, LAI and corm length and yield per plant in genotypic level. The residual effect 0.4762 represent in genotypic level about 53 % of the variability observed for yield per plant was represented by these traits. In the phenotypic level highest and positive direct effect was observed with petiole length and yield per plant. Positive direct effect was also found on yield per plant by plant height, petiole length, inflorescence length, inflorescence number, spathe length and spathe breadth, corm length, corm breadth. The residual effect 0.4235 means that characters included in the present study explained about 58 % variability in yield per plant at phenotypic level. Keywords: Alocasia macrorrhiza; Genotypic correlation; Phenotypic correlation coefficient; Direct and indirect effects Introduction The underutilized crops, giant taro ( Alocasia macrorrhiza L.) locally called mankachu belongs to the family araceae (arum) is the staple food in many countries e.g. Hawaii, PNG, Fiji and important secondary food over the Africa and Asian countries (Coursey,1967; Plucknett,1970, Purseglove,1972). Giant Taro is a succulent herbaceous plant, reaching 4.5m in height with a thick cylindrical stem arising from a basal corm. In Bangladesh two types of giant taro were found in local diverse areas. The cultivar giraman possessed high weight due to large corm length and corm breath, leaf sizes were gigantic, vertical, where dheki man possessed small sized corm due to short length and breadth of the corm and relatively saliently small leaf sizes. In Bangladesh, several types of Aroid genera and species occur in different locations /districts, which can be categorized into edible, poisonous, medicinal and ornamental Alocasia, originated in native in Ceylon (Srilanka) but widely distributed in the South East Asia subcontinent, Malayasia, Indonesia and Polynesia and has spread to parts of tropical America (Leon,1977).The food value of the edible portion of the raw stem tubers of giant taro has been reported as energy 293-599 k /100g; water 63-81 percent, crude protein 0.6-3.3 percent; fat 0.1-0.2 percent; Carbohydrate 17-27 percent; ash 1.1-1.3 percent, calcium 46-153mg /100g.; iron 0.5-1mg /L 100g; phosphorus 45-72 mg /100g; niacin 0.4mg /100g.; riboflavin 0.02-0.03mg /100mg; thiamine 0.09-0.1mg /100g; ascorbic acid trace *Corresponding author: E-mail: (Rashid and Daunicht,1979). The corms are baked, roasted and boiled and have great importance as a gift on formal occasions as well as industrial purposes. It has also medicinal properties such as useful in inflammations, leprosy, disease of the abdomen and spleen, leaf is used against tumours and stings of insects. Tuber is used in rheumatism, anasarca, jaundice and leprocy, mild laxative and diuretic, petioles are used for toothache and their juice for cough, earache and stomachache (Ghani, 1988; Ahmed, 2003). So Alocasia can play a significant role for nutrient status, medicinal and industrial values. Tuber yield is a complex character and governed by the number of component characters. For rational approach towards the improvement of yield selection has to be made for the components of the yield. Therefore the knowledge of association of component characters with yield is of great importance to plant breeders as it helps in their selection with more precision and accuracy. The degree of relationship and association of these components with yield can be measured by the correlation coefficient studies. Estimation of genetic association along with phenotypic correlation not only displays a clear picture of the extent of inherent association but also indicates how much of this phenotypic ally expressed correlation is influenced by the environment. Path coefficient analysis on the other hand determines the direct and indirect contribution of the characters on yield (Wright, 1921).Therefore correlation 118 Correlation and path coefficient analysis in Giant Taro couple with path coefficient analysis will be an important tool to find the association and contribution of yield components to yield. Therefore the present investigation was undertaken to determine the nature and magnitude of relationships between yield and yield components and path coefficient analysis (direct and indirect effects) of yield and yield contributing characters in genotypic & phenotypic level in giant taro (Alocasia macrorrhiza L). Materials and methods Plant materials 407 edible giant taro accessions were collected from aroid growing thirteen districts ( Rajshahi, Satkhira, Jessore, Bogra, Joypurhat, munshiganj, Joydevpur, Mymensingh, Barisal,kustia, Nagaon, Tangail, Khulna ) of Bangladesh in 2006 - 2007. Collected propagules are the mainly plantlets, suckers. Propagules are maintained and were grown in loamy soil in a single row of 4 meters length with inter row spacing of 100 cm. Selected plantlets/setts were used for propagating materials. This investigation was conducted at the experimental farm of the Institute of Biological Sciences research field at Rajshahi University, Rajshahi during the on set of rainy season 2006-2008 .The land in which the experiment was carried out was medium high. The soil was part of Level Barind agroecological zone marked by sandy loam with pH 6.5. The rainfall distribution in rabi season was very low or scanty (<40 cm). So that at least 3 – 4 times flood irrigation were necessary. All recommended agricultural practices were followed for this crop. The experiment was set up with superior genotypes in a Randomized Complete Block (RCB) design with three replications. In each experimental plot plant propagules are planted with row to row spacing was 1m x1m and Plant to plant spacing was 1m. All recommended agricultural practices were followed for this crop production. Data recording Agro-morphological data were collected during optimum vegetative growth following descriptors of Taro with necessary modifications (Anonymous, 1999). The morphological characters were recorded from randomly selected five plants from each accession between 190 days after planting, (...truncated)