No abstract

This study examined the effect of chitosan elicitor with four different concentrations (0, 0.2, 0.4 and 0.6 g/l) on physiological and biochemical properties of stevia under four levels of salinity stress (0, 50, 100, 150 mM level of NaCl). Salt stress caused reduction of chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll, carotenoid and total protein content. The increment of malondialdehyde (MDA) content was not significant in all NaCl levels, while the CAT and POX activities were increased as well as stevioside and rebaudioside A under salinity stress. On one side, chitosan treatments could compensate the reduction of physiological traits such as photosynthetic pigments and protein content. On the other side, chitosan caused multiple increases in malondialdehyde content, antioxidant enzymes activity (catalase and peroxidase), steviol glycosides (stevioside and rebaudioside A) under salt stress. We report for the first time, the potential of chitosan to enhance salinity-tolerant abilities in stevia through increment of the salt-adaptive factors and to diminish harmful damages caused by NaCl stress.

Saffron (Crocus sativus L.) which contains exceptional anti-cancer properties is presently the world's most expensive spice. Iran is known as the original habitat of Crocus L. and a significant source of high-quality cultivated saffron production and export. Considering the importance of this species, we used 27 microsatellite markers to assess molecular variability and discriminating capacity of markers regarding their effectiveness in establishing genetic relationships in Iranian Crocus ecotypes. Thirty eight Iranian cultivated saffron ecotypes and 29 wild allies were evaluated in this research. The results from molecular analyses, including a molecular phylogenetic network and RB analysis, revealed two major groups and five subgroups, regardless of their geographical origins. Also, the results showed a clear distinction between C. sativus and other species of Crocus genus, taking into account their close relationship with C. speciosus and C. hausknechtii, which are assumed to be the two closest relatives of Iranian cultivated saffron among species studied. In this paper, we observed for the first time extensive genetic diversity among Iranian C. sativus despite their asexual reproduction. Considering suitable climatic conditions in Iran for cultivating saffron and the country’s leading high-quality production of Crocus sativus worldwide, studies on great genetic variability among Iranian C. sativus ecotypes as well as wild relatives native to Iran will further highlight the value of this crop. In addition, our results provide valuable information for genetic improvement, reduction of strong genetic erosion, and conservation of costly heritable resources of C. sativus in future breeding programs.