پژوهشنامه اصلاح گیاهان زراعی
پیاپی 4 (زمستان 1388)

In order to estimate narrow-sense heritability and heterosis for phenological traits, plant height, seed yield and oil yield, F2 progenies of half diallel crosses from six varieties including RAS-3/99, RW008911, 19H, RGS003, Option500 and PF7045/91 along with their parents were evaluated in a randomized complete block design with 3 replications. Diallel analysis revealed significant mean squares of general and specific combining abilities (GCA and SCA) for all traits, indicating the importance of additive and non additive genetic effects for these traits. However estimating of high narrow-sense heritability and degree of dominance less than one for phonological traits showed the prime importance of additive genetic effects for these traits. Heterosis range in comparison with superior parent were varied from -11.88 to -0.75, from -10.06 to -0.13, from -10.67 to -2.50, from -32.03 to 11.21, from -477.33 to 711.98 and from -327.12 to 274.62 for days to flowering, days to end of flowering, days to maturity, plant height, grain yield and oil yield, respectively. The highest yield (3431 kg/ha) was belonged to Option500 × PF7045/91.

In order to identify restorer lines in hybrid rice system, sixty lines and cultivars were studied. Two STS makers of RG140 that is linked to Rf3 locus on chromosome 1 and S10019 that is linked to Rf4 locus on chromosome 10 were used to screen restorer line. Then, after digestion with two restriction-enzymes (EcoRI and FnudII), the results showed that 27 lines had Rf3 gene, 3 lines had Rf4 gene and 20 lines had both fertility restorer genes (Rf3 and Rf4) with more than 85 percent fertility based on phenotypic test. Therefor these lines can be used as restorer lines in hybrid rice seed production. However the other lines with less than 85 percent field fertility can not be used as restorers.

In order to find drought tolerance cultivars and determine the appropriate Indices to select drought tolerance in sunflower hybrids, an experimental research was conducted as split plot design based on RCB at the research field of college of Abouraihan of university Tehran in Iran-Pakdasht, in 2009. Irrigation rates were considered in the main plots and sunflower hybrids as sub plots. The result showed that drought tress severely reduced seed weight, seed number per head and grain yield. The Allstar and Azargol hybrids in terms of optimum irrigation with 3448 and 2793 kg.ha-1 and in severe drought conditions Allstar and Hysun 25 hybrids with 829 and 704 kg.ha-1 had the highest grain yield. In order to determine the best indices by their correlation with yield and by exploring biplot and three dimensional graphs in moderate drought conditions GMP and MP indices and in severe drought conditions GMP and STI indices to select the best drought tolerance of sunflower hybrids were detected. Also based on the results of three-dimensional graphs in both moderate and severe drought stress conditions Allstar was the superior to others.

Lectin protein is considered as an important anti-nutrient factor in soybean seed. A low quality soybean proteins is associated whit the presence of lipoxygenase protein due to its unfavorable flavor. This research was conducted at the Sari Agricultural Sciences and Natural Resources University, during 2008-2009 to evaluate the effect of Gamma rays on anti-nutrient protein of Hill cultivar. M1 generation seeds were obtained and grown as plant-to-row in next generation. In M2 generation, highly variation was observed for plant height, flower color, sterility, leaf shape, early and late maturity, that among mutant plants with favorable morphological traits were selected. After protein evaluation by SDS-PAGE it hasnt shown the lectin protein in M-107 plant mutant and also anti-nutrient factor of lectin and lipoxygenase was absence in M-729 mutant. However, these two mutant plants which hadnt shown one or several subunit proteins, but not showed meaningful commutation in total volume protein and oil content. These two mutant plants can be considered very important for improving seed proteins in soybean breeding programs.

Tea (C. sinensis L.) is the most important beverage crop in Iran and genetic base of current Iranian tea shrubs were achieved from three mass seeds namely: Dhongan, Batjan and Raighur. In this study, genetic diversity of 30 cultivated tea clones were evaluated using 45 RAPD markers and 13 morphological and 4 chemical characters respectively. Sixteen and of 45 markers produced 96 bands that 89 bands among clones were polymorphic and monomorphic respectively (92.71% polymorphic). Bands size was variable between 250-2500 base pair. Three main groups could be recognized from cluster analysis based on markers data: The first group consisted of internal selective clones, narrow Russian leaf and Seri-Lanka clonal cultivar (3020, KEN, DN). The second group consisted of Seri-lanka clonal cultivar (3013, 3019), Blead Russian leaf, Darjileing 27, clon100. The third group consisted of Yaboukita clonal cultivar, Darjileing 21, Assamica clonal cultivar, Darjileing 13 and Darjileing 18. The average gene diversity between clones based on Nei's index is estimated 0.34. The morphological and chemical investigation, placed of clones in denderograme are approved based on RAPD markers.

In order to study the genetic control of root yield, sugar yield and white sugar yield in tropical beet, the biplot of diallel data was used. 36 hybrids derived from crosses among 9 sugar beet genotypes along with four control treatments were evaluated at Safiabad Agricultural Research Center, Dezful, Iran during 2008-2009 growing season. The experimental design was a triple lattice design with three replications. Analysis of variance showed significant differences among genotypes for the traits at 1% probability level. Analysis of combining ability using Griffing's method II Diallel crossing scheme after elimination of the control treatments indicated that general combining ability of genotypes was significant for all three yield traits at 5% probability level. Also specific combining ability was significant for root yield and sugar yield at 1% probability level and at 5% probability level for white sugar yield. The GGE bi-plot graphical were used for evaluation of O-type line potential. For root yield, 436-104 was the best general combiner. Also 7173 and 474 parents were the best specific combinatory, so that 7173×474 cross was the best hybrid for root yield, sugar yield and white sugar yield traits in sugar beet. 436 genotype was the best tester for sugar yield and white sugar yield traits.