فهرست مطالب a. valizadeh

Pseudomonas aeruginosa (P. aeruginosa) is one of the opportunistic pathogens in hospital that afflicts patients with burning damages، respiratory diseases، cystic fibrosis، bacterinemia، septicemia and many of other prevalent infections. P. aer-uginosa has two types of cyclic PAPI such as PAPI-1 (108 kb) and PAPI-2 (11kb). The big island، namely، PAPI-1 has an important role in virulence، evolution and development of pathogenic process of the bacteria. Many cellular contamination capa-bilities of the bacterium including chronic infections in people with cystic fibrosis are arisen from function of the gene. The aim of this study was to evaluate the frequency of PAPI-1 gene in clinical isolates of P. aeruginosa.

Clinical isolates of P. aeruginosa were identified by traditional methods. After extraction of genomic DNA، the existence of PAPI-1 coding gene was confirmed by using polymerase chain reaction (PCR).

Of the isolates under study، 17 samples (35. 41%) contained PAPI-1gene. Among 29 samples of urinary tract origin، 9 samples (31. 03%) contained PAPI-1 gene and from 19 samples of burn injuries، 8 samples (42. 1%) contained PAPI-1. This big island of P. aeruginosa، namely، PAPI-1، was equally existed in burning and urinary infection samples. Discussion &

Results of the present study indicated that the big island، PAPI-1، in PA14 strain of P. aeruginosa has a very wide role in bacterial infections. These results revealed the active presence of this big island in the development of pathogenicity and bacterial infection capa-bility by P. aeruginosa.

Introduction of high yielding as well as high quality rice cultivars is one of the most important activities at Rice Research Institute of Iran (RRII). In 1991, 210 rice lines introduced from International Rice Research Institute (IRRI) to Rice Research Institute of Iran were evaluated in observational and statistical experiments in Mazandaran for two years, and seven lines were selected. These lines had better performance in morphological characteristics, early maturity and yield than other lines. Results of additional experiments showed that Fajr cultivar was high yielding and stable in different environments of Mazandaran province. This cultivar had medium maturity with average yield of 6.5t th-1. According to agronomic experiments, the best planting space for this cultivar was 20 20 and 14 30 cm for traditional and machinery transplanting, respectively. Based on soil analysis and crop requirements, 115, 50 and 50 kgha-1 N, P2O5 and K2O are recommended, respectively. Results revealed that this cultivar is similar to Nemat and Dasht cultivrs in response to diseases and pests, but it is much more tolerant to lodging. Plant height and 1000-grain weight are about 108 cm and 24g, respectively. Fajr is one of the most superior improved rice cultivars with a high cooking quality, which has ever been introduced to the farmers of Mazadaran province since RRII establishment. Due to high adaptability of this cultivar, its cultivation could be extended to other provinces like Golestan, Fars and Khuzestan.

Several crosses have done between local rice cultivars and improved varieties in order to improve and releas high yield withing cultivars with suitable quality characteristics during lastthree decates in Iran. A hybridization breeding program with high emphasis on quality started in 1985. In that program, two groups of riice cultivar (localaromatic cultivars and high yielding improved ones) werecrossed in all possible mating systems (complete dialllel crosses). Suitable crosses were sellected and segregating generation were handled based on the pedigree method. Quality analysis of the selected sigle plant and lines were done in each generation. Finally six promisiing high yielding lines with good cooking and eating qualities were obtained from Sang Tarom and Hassan sarai with Amol 3. One of them D2-12-54, showed superiority in sense of yield and quality, comparing to others improved cultivars as well as Amol 3 and Nemat cultivars. Quality and some important agronomy characteristics of D2-12-54 (Neda c.v.) are as follows: Amylose content 26.2 percent gelatinization plant heigh 100 cm panicle length 26cm 1000 grain weight, 30gr maturity length 130 days average yield 8384 Kgha-1 resistant to blast and tollerant to stem borrer.