TY - EJOUR AU - Jaffari, Ali Ashraf AU - Nasiri, Mohsen AU - Jafari, Ali Ashrafe AU - Hoseini, Leila Flah PY - 2024 DA - January TI - Investigation of Chilling Effects on Characteristics of Seed Germination, Vigor and Seedling Growth of Nepeta spp. Species T2 - Journal of Rangeland Science VL - 5 L1 - https://oiccpress.com/journal-of-rangeland-science/article/investigation-of-chilling-effects-on-characteristics-of-seed-germination-vigor-and-seedling-growth-of-nepeta-spp-species/ N2 - To study the effects of chilling on dormancy breaking and the increased germination characteristics of Nepeta (germination percent and speed, seedling length, vigor index, wet and dry weight), a factorial experiment in a completely randomized design with 4 replications was implemented in a laboratory in 2014. Factor A was the chilling treatment in three levels (control, one-month and two-month pre-chilling of wet seeds at 4°C) and factor B was related to the seeds of 10 different species of genus Nepeta. After chilling, seeds of control were placed in a germinator for 15 days at 20°C and light-to-dark cycle of 16 hours light (1000 lux) to 8 hours dark. The results showed that chilling treatments had significant effects (p<0.01) on germination percent, germination speed, vigor index and fresh weight, but they had no effects on the seedling length. The chilling effects on germination percent showed that one-month chilling had a positive effect on N. haussknechtii with 40% and N. menthoides with 36.5% and two-month chilling had a positive effect on N. haussknechtii with 43%. The two-month chilling effect on germination speed was positive for most species. Generally, one-month chilling had positive effects on the increased seed vigor index of N. betonicifolia, N. haussknechtii  and N. menthoidesand by 20.48%, 25.33% and 17.99%, respectively as compared to that of control treatment and two-month chilling had positive effects on the increased fresh weight of N. cataria, N. haussknechtii , N. pungens, N. menthoides andN. crassifolia. IS - 4 PB - OICC Press KW - Germination, Chilling, Normalized Difference Vegetation Index, Drought Monitoring, MOD13A3, Tokunaga-Thug method, Semi-arid region. ,, Nepeta, Dormancy breaking EN -