fatemeh jamali; vahid Etemad
Abstract
Research on the effect of salinity and drought stress on germination and growth pattern among pasture grass populations is very important to determine the potential of suitable species for restoration and protection as well as fodder production. For this purpose, a research was carried out to evaluate ...
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Research on the effect of salinity and drought stress on germination and growth pattern among pasture grass populations is very important to determine the potential of suitable species for restoration and protection as well as fodder production. For this purpose, a research was carried out to evaluate the salinity and drought stress of the Pennisetum divisum plant in the germination and seedling growth stage of 2019 in the seed laboratory of the Faculty of Agriculture of Tehran-Karaj University in the form of a completely randomized design and in 3 replications. The treatments of this experiment included 4 levels of salinity (100-150-200 and 300 mM sodium chloride), 4 levels of dryness (2-, 4-, 6- and 8-bar polyethylene glycol) and distilled water (control). The evaluated traits included germination percentage, germination speed, stem length and root length. The results showed that the germination percentage, germination speed, root length and shoot length increased with the increase of salinity stress up to 200 mM and then decreased so that practically no seeds germinated. In drought stress, the studied traits increased up to -6 times and then started to decrease. The results showed that the Pennisetum divisum plant is relatively resistant to salt and drought stress.
javad mirzaei; mehdi heydari; shirzad Gerayli; vahid Etemad; mehrdad zarafshar
Abstract
To understanding of effect of canopy gap disturbance on quantity and quality of seed germination of forest trees, seeds of two economic trees in Hyrcanian forest including Fagus orientalis and Carpinus betulus were collected from some canopy gaps with different sizes and their germination parameters ...
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To understanding of effect of canopy gap disturbance on quantity and quality of seed germination of forest trees, seeds of two economic trees in Hyrcanian forest including Fagus orientalis and Carpinus betulus were collected from some canopy gaps with different sizes and their germination parameters were studied. In this regard, 48 canopy gaps were identified from a mixed Fagetum stand at Hajikola-Tirankli forestry plan from Tajan River watershed. In the following, the canopy gaps were classified to three difference size classes such as smaller than 150 (small), 150-350 (moderate) and 350-500 m2 (large) and the seeds of the Beech and Hornbeam were collected from inside and outside of the canopy gaps and seed germination test were done on the collected seeds. Seed germinant percent, germination speed and mean seed germination time were calculated and then statistically analyzed. Comparison of the collected data showed that there is no considerable difference between natural and artificial canopy gaps in aspect of seed germination parameters while for both species, collected seeds from moderate and large canopy gaps had higher seed germination and sometimes germination speed. It seems that optimal environmental condition such as moisture, temperature and light is better provided in canopy gaps bigger 150 m2 for seed germination of both species. Same research would be suggested on the other tree species.
