Response of Yield, Yield Components and Nutrient Concentration of Cumin (Cuminum cyminum L.) to Mycorrhizal Symbiosis under Salt Stress Conditions

To study the effects of mycorrhizal inoculation and salinity stress on the growth, yield and nutrient concentrations of cumin (Cuminum cyminum L.), an experiment was carried out as split plot in a completely randomized block design at Zabol University Research Farm in 2013. Treatments consisted of three salinity stresses: 1 (control), 5 and 10 dSm-1, was considered as the main treatments, and four levels of mycorrhizal inoculation (Glomus intraradices, G. etanicatum, G. hoi and non-inoculation as control) as the sub-treatments. The effects of salinity on all traits under study, except umbers per plant, were significant, and severe stress (10 dSm-1) reduced 100 seed weight, number of seeds per umbel, concentrations of phosphorus, calcium and magnesium in seeds by 17.71, 11.4, 14.95, 46.08, 13.60 %, respectively, as compared to the control. The numbers of seeds per umbel and phosphorus concentration in seed were highest in G. intraradices with 28.4 and 54.4%, respectively as compared to control and umbels per plant was also maximum (9.7) by using G. etanicatum. Mycorrhizal inoculation did not have significant effect on calcium and magnesium concentrations in seeds and 1000 seed weight. However mycorrhiza × salinity stress interaction was significant about concentration of sodium, potassium and sodium to potassium ratio (Na/K) in seeds, as well as seed yield and seed number per plant. Among the species of mycorrhiza, applied G. intraradices had better performance in severe salinity (10 dS-1) and increased seed yield and seed number per plant by 28.5 and 47.6%, respectively in comparision control. The results suggested that mycorrhizal inoculation improves water absorption by plant. Yield increases of plants under different salinity regimes dependent on their mycorrhizal inoculation.