فهرس المقالات Cold Treatment

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  1 - The Effect of Different Concentrations of Gibberellic Acid on Quantitative and Qualitative Characteristics of Three Cultivars Lacourtine, Yokohama and Red Favourite Tulip (Tulipa gesneriana L.)
  Khani Shakarami Rohangiz Naderi Mesbah Babalar Zeinab Hamzehei1
  Tulip is one of the most important flowers to precocity. Treatment of tulip bulbs with gibberellic acid reduces the forcing period in the greenhouse resulting energy saving and reduces the tulip’s physiological disorders. This study carried out about three tulip c أکثر

  Tulip is one of the most important flowers to precocity. Treatment of tulip bulbs with gibberellic acid reduces the forcing period in the greenhouse resulting energy saving and reduces the tulip’s physiological disorders. This study carried out about three tulip cultivars includes ‘Lacourtine’, ‘Yokohama’ and ‘Red Favourite’. The results showed that gibberellic acid reduced significantly stem length, first internode length and duration of precocity period. Based on the results gibberellic acid at 250 and 500 ppm can be effective agent in tulip’s precocity. تفاصيل المقالة
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  2 - Studying the Impacts of Cold Temperature on Morphological and Phonological Development of Poa pratensis and Poa trivialis Regarding GDD
  Ebrahim Baghdadi Ali Ashraf Jafari Mohammad Ali Alizadeh Amir Hossain Gorji
  Poa genus has a high value for grazing and forage conservation concerning thelivestock. In order to study the impacts of cold temperature and Growing Degree Days(GDD) on seedling morphological trait and phonological development of two speciesinvolving Poa pratensis and أکثر

  Poa genus has a high value for grazing and forage conservation concerning thelivestock. In order to study the impacts of cold temperature and Growing Degree Days(GDD) on seedling morphological trait and phonological development of two speciesinvolving Poa pratensis and Poa trivialis, this research was conducted in laboratory andgreenhouse and outdoor of Research Institute of Forest and Rangeland in Tehran, Iran. Theseed samples were moist chilled at 4 °C for two weeks as compared to the control treatment.Samples of both treatments (chilling and control) were transferred into a germinator at20±4°C for 15 days. All the pots were placed in a normal glasshouse at 20±10°C for onemonth. The 30th day age pots have been transferred into the cold rooms at 4°C for two weeks incomparison with control treatment. The seedling vegetative traits were measured same as thelaboratory. For outdoor experiment, half of pots of greenhouse were transferred outdooruntil their flowering and growth stages and GDD were recorded. In the flowering stage,morphological characteristics including stem number, stem length, peduncle length,panicle length, plants‟ fresh and dry weight of each ecotype were recorded. The collecteddata of each experiment were separately analyzed using factorial experiment based oncompletely randomized design. The results of laboratory experiment showed thesignificant effects of chilling (4 °C) treatment on germination percent, speed of germinationin both species and vigor index for P. pratensis. Regarding P. pratensis in vegetative stage,the mean values of all of traits were higher in control treatment than those of coldtreatment. Similarly, in outdoor experiment, the mean values of reproductive traits in thecontrol treatment were higher than those for cold treatment concerning both species. P.pratensis had higher mean values for all of reproductive traits as compared to P. trivialis.Results also showed that GDD of plants which were subjected to cold treatment werelower than those for control treatment for both vegetative and flowering stages. It has beenconcluded that cold treatment reduced flowering dates in reproductive stage. تفاصيل المقالة