M Assadi, F. Ghahremaninejad, T. Nejadsattari, I. Mehregan, K. Poursakhi,
Volume 14, Issue 3 (10-2014)
Abstract
Genus Cerastium belongs to the subfamily Alsinoideae. This genus is represented with about 30 species in two subgenera (subgenus Dichodon and subgenus Cerastium) and three sections (sect. Strephodon, sect. Orthodon and sect. Schizodon) in flora Iranica area, of which 19 species were reported from Iran. The materials in the TARI herbarium were studied. The vegetative and reproductive characteristics of specimens were checked by stereomicroscope. In family Caryophyllaceae, the seeds bear numerous characters which can be used for taxonomic purposes. The ornamentation features of the seed surface and its relief are different from one species to another. The seeds were carefully taken from mature and dehiscent capsules. Pollen grains obtained from flowers bearing mature anthers. In this paper, Cerastium pentandrum (Caryophyllaceae) is reported as a new record from northwest Iran and Iranian plateau. It belongs to the subg. Cerastium sect. Orthodon. In this section teeth of the capsule are elongated, straight or reflexed, with flat or recurved margins. Morphological characteristics of the new record are provided. This taxon is compared with its closest relative C. balearicum. The ultrastructure of seed and pollen is examined by SEM.
R Ghafari, Fariba Meighani, F Ghasemkhani, H Salimi,
Volume 15, Issue 1 (4-2015)
Abstract
Abstract
Mesquite is one of the invasive, problematic and noxious weeds and special warm and dry areas. This plant in recent years due to high resistance to drought stress level in the vast agricultural lands and orchards spread. Management so it is very important. The following studies were conducted in plant protection of weed research Department Research Institute of during the years 2010: 1- Effect of constant temperature on germination that including 5, 10, 15, 18, 20, 25, 30, 35 and 40° C independent dark and independent light conditions 2- Effect of temperature fluctuations on seed germination: 0/10, 10/20 and 20/30° C 3- Effect of planting depth seed on seed germhnation. All experiments were conducted with 4 replications. mesquite seeds showed no dormancy when detachment from mother plant. Seed germination was strongly influenced by temperature. Light did not play a crucial role on seed germination of this weed. Therefore mesquite seeds were not photoblastic and temperature fluctuations did not increase seed germination of mesquite. The above characteristics are very important in making mesquite an invasive weed. Having precise information of these traits enables us to a better management and control of this troublesome weed.
Keyword: Prosopis farcta, seed germination, seed dormancy, constant and fluctuating temperature, planting depth.
