Assessing the relationships of lint-yield and cottonseed-yield with some agro-morphological traits of Gossypium hirsutum var. Varamin by path analysis

Assessing specific relationships among lint-yield, cottonseed-yield and some important agro- morphological traits, in commercial varieties of Varamin, was the main objective of the present study to use in the future breeding programs. To achieve the above objective, the seeds were planted in 10 lines with 2 meters long in each block, based on RCBD with three replications during 2009-2010 years. Plant height, number of bolls per plant, mean boll weight, leaf length, leaf width, number of branches per plant, length of fiber, chlorophyll content, fiber yield, lint percentage, lint-yield and cottonseed-yield were measured. Correlation analysis indicated that the traits of boll weight, (r= 0.97), cottonseed-yield (r=0.93), fiber weight (r=0.90), leaf width (r=0.77), fiber length (r=0.70), leaf length (r=0.66) were significantly correlate with lint-yield. Stepwise regression results for lint-yield, as dependent variable, showed that the traits of boll weight, fiber weight, lint percentage and number of bolls per plant were respectively entered in the regression model, as the most effective independent variables. Path analysis results indicated that the trait of boll weight had the maximum direct effect (0.366) and the traits of boll weight and lint percentage had the maximum indirect effects (by increasing fiber weight character) on lint yield. Total results showed that the trait of boll weight had the maximum direct and indirect effect on increasing lint- yield therefore, we can use it in the future breeding program for improvement of lint-yield. Lint-yield and lint percentage were the most important characters on increasing fiber weight. In other words, these two above-mentioned traits had the maximum direct and indirect effect on fiber weight, respectively. Finally, the traits of boll weight and lint-yield were recognized the most important characters for improving cottonseed-yield of Varamin cultivar.