rezagholi mirfakhraei

In plant breeding program to produce hybrid varieties, pair of male sterile and restorer fertility lines are required. Differentiation of lines possessing restorer fertility allele from the lines lacking it remove the need for the progeny test, and thus reducing the time and the cost in the hybrid production procedure. Canola breeding program in Iran has concentrated toward production of domestic hybrid varieties, however, it suffers from lack of molecular information in restore fertility status of lines, and therefore it needs time and tedious activities. To design gene-based markers for distinguishing R-, A- lines and hybrids in sunflower breeding programs. Aligning sequences of locus responsible for male sterility and that of male fertility resulted in finding differences in the loci, which used to define two set of suitable primer pairs. Genomic DNA from 25 R-lines (23 inbred lines and two commercial lines), 9 A-lines (7 inbred lines and two commercial lines), one B-line and two commercial hybrids were extracted and used in PCR as template. Using one-primer pairs, a band of nearly 1500 bp was amplified in restorer lines but not in A-, B- lines. Another primer pair used to distinguish hybrids (heterozygout) from restorer lines. Results of the report is predicted to be used in canola breeding for hybrid production. Although the molecular bases for the male sterility and fertility restoration in rapeseed is not published, taking advantages of gene-based markers, make rapeseed breeding program more efficient regarding time and costs.

The low temperature is one of the most important factors limiting the growth, production and geographical distribution of plants. This stress may occur as chilling, freezing, and late spring low temperature. In spring, simultaneously with the beginning of wheat growth, tolerance to low temperatures is reduced and may be faced with decreasing temperature at any stage of its growth and damaged. This type of sudden temperature drop in spring is known as late spring frost. This investigation evaluated cell membrane stability in selected cultivars of bread wheat that affected by late spring low temperature, in 50-68 Zadoks codes. The experiment was carried out in a randomized complete block design with two factors, 13 cultivars and three late spring low temperature treatments including (control), 0, and -2°C. Membrane lipid peroxidation and electrolyte leakage were analyzed as the most cell membrane stability indices. Regarding to significant differences at the 5% probability level for genotype × stress interactions in traits, comparison of means showed that there were various responses among the cultivars. Finally, based on the results, cv. Pishgam was assessed as resistant and cv. Sivand susceptible to late spring low temperature according to the amounts of measured indices.

Genetic diversity is necessary for breeding program and increasing genetic gain of selection in crop plants. With the onset of spring growth, Spring cold stress is a problem for wheat crops at heading and also may be damaged some other parts of this plant. The aim of this study is the investigation of genetic diversity duo to artificial cold stress on the physiological traits, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and cytoplasmic membrane stability at the reproductive stage. For this purpose an experiment with 20 cultivars of bread wheat and four levels of cold stress, (8 (control), +2, 0 and -2 Celsius) was performed in factorial arrangement in a completely randomized design. Results of variance analysis showed the effects of interaction between cultivars and cold stress levels is significant at the 5% level which showed the existence of genetic diversity between studied cultivars.. There were significant correlations between chlorophyll a, b, total and carotenoid. In order to determination of genetic relation between cultivars, cluster analysis using was performed Ward method and cultivars were divided into 5 groups at -2 °C and 4 groups at +8 °C. Discriminate function and principal component analysis confirmed the results of cluster analysis. The third group of -2 °C including of GHODS, TAJAN and PISHTAZ had the lower level of ion leakage and higher level of plant pigments.