اصلاح و تهیه لاینهای خوش کیفیت برنج

To determining physico-chemical traits that can effect on rice quality and classifying them, 50 genotypes of rice varieties selected and planted in the same condition. In this research, 23 quality traits were evaluated. Analysis of variance showed a high significant difference among genotypes. Mean comparison showed that improved varieties are better than local varieties for physical traits, but local varieties are better than improved rice varieties for chemical, cooking and nutritional traits. In the present study, genetic diversity in 96 rice variety evaluated by using of 14 agro-botanical traits and 23 SSR Markers. The aim of the work was to study variation between varieties with molecular and morphological data and to use in a future breeding program. Extracted genomic DNA of each plant extended with 23 SSR primers and electrophoresis on denatured polyacril amid gel. Morphological traits were measured in a field experiment in an augmented randomized complete block design with 5 replications. Totally 112 polymorphic bans were observed in the studied populations. Among the primers used, RM481 and RM592 showed the highest polymorphic band (10 bands) and RM443 and RM184 showed the lowest polymorphic band (2 bands). In conclusion SSR markers can be used as power full tools for assessing inter and intra populations genetic diversity as well as genetic differentiation and identification. Rice grain Quality includes the milling, appearance, cooking and eating qualities. Amylose content (AC), gelatinization temperature (GT) and gel consistency (GC) are important traits determining rice eating and cooking quality. A population of F2 derived from Hashemi ا Neamat cross was used to study the genetic control of AC, GT and GC traits. From 150 microsatellite markers were tested on both parents just 62 of them had different bands for tow parents in electrophoresis procedure and used for linkage map. Two different QTL analysis methods were used to identify QTLs controlling eating quality, that the result of them approximately was the same. Eight QTLs for AC were detected on Chromosomes 3 (two QTLs), 4(one QTL), 6 (four QTLs) and 12(one QTL). One major QTL on chromosome 6 (ac6a) was detected that explained 52% of phenotypic variation. Two QTLs on chromosome 1, six QTLs on chromosome 6 and one QTL on chromosome 12 were detected for GT. Four major QTLs were mapped on chromosome 6 (gt6b, gt6c, gt6d and gt6e) that they wre closed to each other. Ten QTLs were detected for GC, one on chromosome 3, one on chromosome 4, six on chromosome 6, one on chromosome 10 and one on chromosome 12. One major QTL were identified for GC on chromosome 6 (gc6a), wich accounted 33% of the phenotypic variation, and it wase the same position with the major QTL for AC trait. Markerassisted selection (MAS) using PCR markers flanking to amylase content were done to assort breeding lines with good eating and cooking quality. This experiment aimed to increase cooking and eating quality by application of DNA markers in the breeding program of rice cooking and eating quality development. In this study, tow microsatellite marker (RM190 and RM276) linked with amylase content were used for screening in 15 F2 population derived from crossing between local and improved variety. Result showed the maximum percentage of plants with same band pattern with local variety were revealed in Abjibooji/Sepidroud crosses and minimum of them were revealed in Gharib/Saleh crosses (47.7% and 17.6% respectively). Also maximum percentages of plants with good band pattern were revealed in Abjibooji/Saleh crosses and minimum of them were revealed in Hashemi/Saleh crosses (33.3% and 13.8% respectively). Maximum percentages of eliminated plant b ased on tow marker result were done in F2 population derived from AhlamiTarom/Saleh crosses and minimum of them were done in Hashemi/Sepidroud crosses (52.2% and 16% respectively). All populations are ready for screening in advanced generation based on improving both yield and cooking quality. Necessary conditions for realizing the new variety were initial known of controlling gene effects of quality traits in segregating generation and selecting by them. Diallel analysis benefit for those genetic evaluations. In two diallel sets selected the best parent by the evaluating genes effects of quality traits special amylase content, variation of dominant and recessive genes, cytoplasm effects, narrow sense heritability, general combination ability of varieties and specific combination ability of hybrids. Initial segregation of generates were F2 population .Three programs used for breeding in every populations: Pedigree, Bulk and Selective Bulk methods. Selected the best plants with measurement of morphologic traits in farm and quality traits in laboratory. Therefore the data of the unreplicated treatments were not adjusted and the average data of genotypes were analyzed. Mean comparison of the traits for check varieties showed that the best f