THE EFFECT OF SALINITY ON RUBINIA TINCTORUM ROOT PIGMENTS AND THEIR RELATIONSHIP WITH SOME SOIL CHEMICAL CHARACTERISTICS

Rubinia tinctorum is a perennial herb plant. It is resistant to salinity and it has one of the strangest plant red colors which are used in the dye industry especially in the carpet industry. The purpose of this study is to investigate the effect of soil salinity on Rubinia tinctorum pigments, in the areas under cultivation of it. So, an experiment was done on the basis of a completely randomized design with three replications. Soil samples were taken from 6 regions under cultivation of Rubinia tinctorum in Yazd province. After determining the electrical conductivity of soil samples, they were classified into three groups of  4, 4-8, and 8-16 ds/m and the effect of salinity on desire parameters was investigated. Data analysis was done using SPSS and Excel software. The results showed that the amount of wool brightness (L*) decreased from 40 to 32.38 following soil salinity increase from the level of less than 4 to the level of 8-16 ds/m, but the amount of A* (redness and greenness) and B* (yellowness and blueness) parameters was increased with increasing soil salinity (P<0.01). The results indicated that there is a positive correlation between B* parameter and soil acidity so that B* parameter increases after increasing acidity (p<0.01). There is a positive correlation between electrical conductivity and A* parameter while there is a negative correlation between L* parameter and EC, Calcium and Magnesium, SAR (p<0.01). Totally, the quality of Rubinia tinctorum color was increased with increasing soil salinity. So, progressing toward economic production of this industrial and medicinal plant is possible by planting Rubinia tinctorum in saline soils which are inappropriate for most plants.