Int.J.Curr.Microbiol.App.Sci (2017) 6(5): 759-775 759 Original Research Article https://doi.org/10.20546/ijcmas.2017.605.086 Correlation Studies on Association of Morphological and Biochemical Traits for Potato Apical Leaf-Curl Disease Resistance or Susceptibility Devashri Maan* A.K. Bhatia and Mandeep Rathi 1 Department of Vegetable Science, 1 Department of Entomology, CCS Haryana Agricultural University, Hisar-125004, Haryana, India *Corresponding author ABSTRACT Introduction Potato (Solanum tuberosum L.) is one of the most important vegetable crops and ranks third among food crops after rice and wheat in India and worldwide from human consumption point of view. India is the 3 rd largest producer of potato in world after China and Russia. During 2010-11, this crop was grown on 18.30 lakh hectares with a production of 36.57 million tonnes (Anonymous, 2011a). Potato is also an important vegetable crop of Haryana. Haryana ranks first in production and second in area among vegetable crops. In 2010-11, the area and production of potato were 26780 hectares and 598164 tones, respectively (Anonymous, 2011b). The productivity of potato crop in the state is quite lower (22.33 t/ha) than the potential yield. Potato crop is attacked by many diseases, which are widely spread and other, which International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 5 (2017) pp. 759-775 Journal homepage: http://www.ijcmas.com High phenotypic coefficient of variation and genotypic coefficient of variation were observed for percent potato apical leaf-curl disease (PALCD) incidence at 40, 60 and 80 DAP, whitefly population at 20 and 30 DAE and phenols. High heritability (broad sense) along with genetic advance as per cent of mean was found in plant height at 60 DAP, per cent PALCD incidence at 40, 60 and 80 DAP, whitefly population at 20, 30 and 40 DAE, phenols, number of stomata per leaf, foliage senescence at harvest, plant vigour at 60 DAP and total yield, indicating simple selection method for the improvement of these traits. Correlation studies revealed that per cent PALCD incidence was found significantly and positively associated with whitefly population and number of stomata per leaf, which indicates that for improving disease resistance, selection should be made for those lines, which have less number of whitefly and number of stomata. The per cent PALCD incidence was significant and negatively associated with plant height, plant vigour, weight of stem per hill, weight of leaves per hill, weight of foliage per hill, leaf area index, total yield, marketable yield, harvest index and phenols which suggests that for potato apical leaf-curl disease resistance, selection should be made on the basis of high values of these characters. Path analysis indicated that the per cent PALCD incidence had positive and highest contribution (1.941) towards plant height at 60 days after planting. Highest indirect contribution was exhibited by plant vigour at 60 days after planting (-0.032) Low population of whitefly, less number of stomata and high phenols were the main characters contributed towards potato apical leaf curl disease resistance. Keywords Potato, apical leaf curl disease, heritability, genetic advance, correlation coefficient. Accepted: 04 April 2017 Available Online: 10 May 2017 Article Info