Abstract

Our objectives were to investigate the effects of salinity on germination and growth of two chamomile species by measuring yield and yield components of Four genotypes ofMatricaria recutita and four genotypes of Matricaria aurea. The genotypes were cultivated in sand in a greenhouse and irrigated with additional nutrient solutions. The treatments included salinity (NaCl) levels of control, 0, 6, 12, and 18 dS m^-1 and two salinity periods; one of them started at seedling stage (35 days after emergence with plants at 8 to 10 leaves) until the end of the experiment (about three months), the other on another part of plants began in stem elongation and seedlings emergence from rosette stage to harvest (vegetative to the end of the experiment) (about 1.5 month). This experiment was carried out as a split-split plot with three replications on the bases of Complete Randomized Design (CRD). The traits measured were plant height (PH), root length (RL), the number of leaves (LN) per plant, node numbers (IN), stem fresh weight and dry weight (SFW) and root fresh weight (RFW) and dry weight (RDW). The salt treatments indicated that dry matter yield decreased with increasing sodium chloride (NaCl) doses. The dry matter yields were higher in control than those in the 18 dS m^-1 NaCl levels. Either the dry matter yields were much higher in stem formation than the early seedling stage period. M. aurea were superior to M. recutita genotypes based on dry matter. Simple correlation coefficient of dry matter (DM) yield components showed that positive and highly significant relationships existed between DM yield with PH, RL, IN, LN, SFW, RFW, RDW and RRW. Path analysis showed that plant height, root fresh weight and stem fresh weight, had strong positive direct effect, in that order node number, stem relative water (SRW) and root dry weight had strong negative direct effect. There was a significant difference between genotypes studied for all traits except for the root relative water (RRW) content. The M. aurea genotypes, especially in Isfahan and Mashhad, revealed more tolerance to salinity.

Key words: Matricaria recutita, Matricaria aurea, salinity, path analysis, salt tolerance.