eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-09-25 13 3 1749 1755 10.13005/bbra/2326 15510 article Amir Ali Najm 1 Farzad Paknejad 1 Ali Kashani 1 Mohammad Reza Ardakani 1 Mohammad Reza Haj Seyed Hadi 2 Department of Agronomy, Faculty of Agriculture and natural resource, Karaj Branch, Islamic Azad University, Karaj, IRAN. Department of Agronomy, Faculty of Agriculture, Roudehen Branch, Islamic Azad University, Roudehen, IRAN. Tuber nitrate is one of the major factors affecting the quality of potato. The present study was conducted to determine the relationships between tuber nitrate and some tuber characteristics (weight, specific gravity, tuber diameter, dry matter percentage of peel, total and peeled tuber, and amount of nitrate in peel, cortex and pith) in Agriapotato tuber by using the statistical analyses of correlations, stepwise regression and path analysis. Peel, cortex and pith nitrate had significantly positive correlations with total tuber nitrate. While, tuber weight, specific gravity, tuber diameters, total and peeled tuber dry mater percentage had negative correlation with the total tuber nitrate. The specific gravity and pith nitrate had the most significant negative and positive correlation with total tuber nitrate, respectively. The results of stepwise regression showed that the pith nitrate, specific gravity and peel nitrate were the important characteristics of tuber nitrate. Path analysis showed that the pith nitrate and specific gravity had highest positive and negative direct effects on the total nitrate. So, in this experiment tuber specific gravity and, pith and peel nitrate had significant effect on the total nitrate and hence tuber quality. https://www.biotech-asia.org/vol13no3/study-of-the-relationships-between-tuber-nitrate-and-some-qualitative-traits-of-potato-tuber-cv-agriaby-statistical-analysis/ Tuber nitrate; dry matter percentage; specific gravity; stepwise regression; path analysis; correlation coefficients