Ebrahim Abedi; Vali Rabie; Malek Ghasemi; Farhang Razavi; Javad Fattahi
Abstract
Information about the temperature requirements in fruit trees has an important effect on productivity and determining suitable regions for their growing. This research was carried out using single node cuttings test in a randomized complete block design with three replications in Citrus and Subtropical ...
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Information about the temperature requirements in fruit trees has an important effect on productivity and determining suitable regions for their growing. This research was carried out using single node cuttings test in a randomized complete block design with three replications in Citrus and Subtropical Research Center in 2015-16. This study was conducted to determine the chilling requirements of Hayward and Tomuri cultivars and male and female golden genotypes using three chilling models (Chilling hours, Utah, Dynamic) and their heat requirements using growth degree hours (GHD) method. Results showed that the chilling requirements of female and male golden genotype buds were 480 and 585 chilling hours, respectively, and for Hayward and Tomuri cultivars were 692 chilling hours. The amount of buds heat requirements in the cultivar and genotype ranged from 2233 GHD in female golden genotype to 4066 GHD in Hayward cultivar. Hayward cultivar required 966 hours of chilling requirement for maximum flowering, meanwhile Tomuri, male and female golden genotype had a similar chilling for both vegetative bud break and flowering including 692, 585 and 480 hours, respectively. With continued sampling, heat requirements reduced and significant negative correlation was found between chilling and heat requirements for bud break. From low chilling requirements of male and female golden genotypes, we can deduce that climatic conditions may be not limiting factor in the leading of them in growing area. It is thought that Utah and dynamic models may be more suitable than hour model to evaluate of chilling requirements.
malek ghasemi; mahsa hashemi sajadi; vali rabiei
Abstract
Thermotherapy is one of the tristeza management methods that was used in this study. Thus 36 ͺ ‘thomson navel orange’ scions on soure orange rootstocks were placed in temperature controlled chamber (TCC) to investigate the effect of thermotherapy on elimination of Tristeza virus. At first, ...
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Thermotherapy is one of the tristeza management methods that was used in this study. Thus 36 ͺ ‘thomson navel orange’ scions on soure orange rootstocks were placed in temperature controlled chamber (TCC) to investigate the effect of thermotherapy on elimination of Tristeza virus. At first, the scions were inoculated by grafting of infected buds and after six months tested by ELISA to ensure contamination. Plants were placed in temperatures including: 40&30, 42&32, 44&340C for eleven weeks, two weeks and 10 days, respectively. In the last temperature, 12 plants dried and in 6 of the remaining plants, there was not verified any infected by ELISA, Direct Tissue Blot Immunoassay and indicator plant tests after three months from the last experiment.Termotherapy is considered as one of the healthy ways of citrus seedlings depending on plant species and viruses infecting alone or together with shoot tip grafting (STG) leads to the production of healthy seedlings. Healthy subjects express differences in the percentage of low initial concentration of virus. The difference in results between studies and other findings show the need and basis for selecting varieties tolerant to heat.