فصلنامه ژنتیک نوین
سال چهارم شماره 2 (پیاپی 17، تابستان 1388)

Estimation of genetic diversity is important because a genetic variability reduction might result to increase vulnerability of crops to environmental stresses, pests and diseases and yield reduction. In this study, genetic diversity between 73 Sardari wheat (Triticum aestivum L.) ecotypes was evaluated by amplified fragment length polymorphism (AFLP) marker. Genetic diversity was analyzed using three pairs of polymorphic primer combinations. Of the approximately 2431 detected AFLP markers by threepairs of EcoRI/MseI primer combinations, 1582 were polymorphic (with average 73.92% polymorphism). Genetic similarity between cultivars was studied by AFLP markers through the calculation of the Jaccard coefficient and UPGMA algorithm. Cluster analysis with the entire AFLP data divided all ecotypes into eight major groups. The results showed a high degree of genetic diversity between the Sardari ecotypes and these ecotypes can be used to introduce new genes in the gene bank. Because of the high genetic diversity between the ecotypes it was conclude Sardari is not a single cultivar, it is the mass of ecotypes. In future preferred ecotypes can be replaced to mass of ecotypes. Also, the results showed that theAFLP analysis is an efficient technology for assessing genetic diversity among wheat cultivars

Lime witches′-broom (LWB) is caused by Candidatus Phytoplasma aurantifolia and is a destructive disease of lime in southern provinces of Iran. Restriction fragment length polymorphism (RFLP) and sequence analyses were used to compare phytoplasmal LWB agents in Kerman, Hormozgan and Sistan- Bluchestan Provinces. Total genomic DNA of infected samples from three provinces was extracted and a 300-bp fragment of 16S–23S rDNA spacer region (SR) was amplified by PCR using P3/P7 primer pair. Amplified products were cloned and sequenced in both directions. Sequence analysis of SR regions showed that phytoplasmal agent of LWB disease in three infected Provinces of Iran, Oman and the United Arab Emarates are Identical. Furthermore, an 1800-bp fragment of ribosomal operon consisting of the 16S rRNA gene, 16–23S SR and 5′-end of 23S rRNA gene was amplified by PCR using P1/P7 primer pair. Amplified P1/P7 fragments were subjected to restriction fragment length polymorphism (RFLP) analysis after separate digestion by Alu I, Rsa I, Taq I, Hinf I, Hpa I and Hha I restriction enzymes. Comparison of RFLP patterns indicated that the phytoplasmal agent of LWB in Kerman, Hormozgan and Sistan- Bluchestan are indistinguishable. Therefore, on the basis of sequence and PCR-RFLP analyses, phytoplasmal agent of LWB disease in Oman, the United Arab Emarates and southern provinces of Iran are identical and probably originated from a common source. To determine distribution of the disease in Kerman province, samples were collected and checked by PCR test during 2004-2005. The results showed that lime is severely infected in lime growing areas of Kerman Province including Kahnooj, Jiroft and Manoojan.