Crop Breeding Journal
Volume:3 Issue: 1, Winter-Spring 2013

Wheat, a globally important food crop, is widely grown in various regions of the world. Wheat’s wide adaptation to different climatic conditions is strongly controlled by vernalization (Vrn), photoperiod (Ppd) and earliness per se (Eps) genes. In this study, 395 Iranian wheat landraces were characterized by applying markers for the vernalization genes Vrn-B1, Vrn-D1, and Vrn-B3. Based on specific primers of the recessive vrn-B3 allele, two novel fragments in addition to the expected alleles were amplified. Spring habit Vrn-D1 and Vrn-B1 alleles were observed in 67.35% and 38.48%, respectively, of Iranian wheat landraces. Twenty-nine landraces were heterozygous for the Vrn-D1 gene. The growth habit of the test wheat landraces could not be completely predicted by their allelic status at the Vrn-1 genes. This inconsistency may be due to misclassification of the growth habit of the studied landraces, the presence of a new mutation at VRN loci in Iranian landraces or other functional genes such as Ppd and Eps genes which were not included in this survey. Therefore, sequencing the putative alleles at various VRN loci of spring and winter types could provide useful information.

Traits such as soluble solids content, fruit acidity, pH, fruit lycopene concentration, fruit beta-carotene concentration, and fruit xanthophyll concentration are very important to the tomato industry. In this study, quantitative trait loci (QTL) analysis of these traits was performed using a recombinant inbred line (RIL) population derived from a cross between a tomato (Lycopersiconesculentum Mill)line, NC84173, and an inbred accession, LA722 (Lycopersicon pimpinellifolium).The two parental lines and the 116 RILs were planted in an alpha-lattice design with two replications. At the end of the growing season, 30-50 representative ripened fruits were harvested randomly from each RIL and the parents to record the traits. A linkage map was constructed using 121RFLP and 67RGA markers arranged in 12 groups. Transgressive segregation was observed for all the traits. A total of 10 quantitative trait loci (QTLs) were detected for the six traits using composite interval mapping. Co-localization of QTLs for lycopene, beta-carotene, and xanthophyll may reflect the pleiotropy effect or genetic linkage between genes via physiological relationships among these traits. This analysis shows that the introgression of wild germplasm may improve the nutritional quality of tomatoes

Rice plants are injured at the seedling stage in early spring in northern Iran. In order to study rice response to cold stress, the expression of OsDREB1A, OsAP37, OsMYB3R-2, and OsNAC6 genes encoding transcription factors was observed in 14-day-old seedlings of cold-tolerant genotype PR and cold-sensitive cv. Hashemi during cold stress (5°C for 24 h) using the differential display method and three replications for each genotype. PCR products were quantified using Total Lab (ver. 1.10) software and significant differences in gene expression were found using Wilcoxon Test of SPSS (ver. 18) software. Transcription factors play an important regulatory role in the response to abiotic stress and interact with cis-elements in the promoter regions of several stress related genes. Different genes displayed different expression patterns in tolerant and susceptible plants during cold stress. While the expression level of OsNAC6 gene increased in both genotypes after cold stress, the expression level of OsDREB1A, OsAP37, and OsMYB3R-2 genes upregulated significantly in PR and decreased in the Hashemi genotype. Results suggest that the expression of genes encoding transcription factors changes in response to cold stress and so could be an informative resource in breeding and biotechnology projects aimed at developing cold tolerance in rice

This study was carried out to investigate the important characteristics in some cultivars/genotypes of Persian walnut (Juglans regia L.), black walnut (J. nigra L.), and walnut inter-specific hybrids: Paradox (J. hindsii × J. regia) and Royal (J. hindsii × J. nigra) in Kamalshahr Research Station in Karaj in 2011-2012. In the study, vegetative vigor was evaluated based on trunk cross-sectional area (TCSA), canopy diameter, nut related traits such as nut weight and size (thickness, width, height), kernel weight, kernel percentage, kernel color, ease of removal, shell thickness, and oil percent. Results showed very high diversity among the species and interspecific hybrids, so that Paradox with 506 cm2 had the highest TCSA, which was 214% more than that of J. nigra. Based on canopy diameter, Paradox showed the most vigorous growth, with an average of 7.95 m, while J. regia with 5.05 had about 37% less vigor relative to Paradox. Regarding nut height, it varied from 3.02 cm to 1.48 cm in J. regia and Paradox, respectively. Nut weight varied from 11.5 g in J. nigra to 3.62 g in Paradox. Principal coordinates (PCO) and cluster analysis were used to classify walnut cultivars/genotypes and interspecific hybrids. According to multivariate statistical analysis, the cultivars/genotypes were divided into three groups: black walnut, interspecific hybrids, and Persian walnut

Peach genotypes showing notable fruit and tree traits were selected in Ardabil and East Azarbaijan Provinces of Iran. Genotypes were grafted on seed rootstocks and cultured with 4×4 m spacing. Traits such as tree growth habit, flowering, maturity, morphological and qualitative fruit characteristics were described in 15 peach genotypes using IBPGR peach descriptors during the 2005-2007 seasons. Variation was found within genotypes for traits such as tree growth habit, bloom and harvest date, yield, fruit weight, soluble solids content, and titratable acidity. Some genotypes had upright or spreading growth habit. Tree vigor was intermediate to strong with green leaf color. Flowering occurred early to late in three years with 10 to 13 days of flowering period. Harvest time varied from early to extremely late (mid-June to late October). Genotypes showed a range of 120±1 g to 275±1 g for fruit weight, 22 to 114 kg for yield per tree, 11.60 to 16.40 °Brix for SSC, 0.54±0.01 to 0.92±0.02% for TA and ripening index from 1.73 to 2.02. Results showed 6 clingstone and 9 freestone genotypes with white and white-greenish to yellow flesh color. Genotypes were grouped into four clusters based on quality traits. High correlation was found between fruit quality traits using principal component analysis. These relationships may help to select a set of genotypes with better fruit quality. Selected genotypes showed good adaptability in Ardabil and East Azarbaijan Provinces and may be released as superior varieties for use in breeding programs

This study was conducted with the main purpose of investigating genetic variation among 13 selected sweet cherry (Prunus avium cv. Siah Mashhad) genotypes, i.e., the most important Iranian sweet cherry cultivars based on their pomological, morphological, and phonological characteristics. The experiment was laid out in a randomized complete block design with three replications at Khorasan-e-Razavi Agriculture and Natural Resource Research Center, Mashhad-Iran, during 2007-2009. Wide variation in pomological (fruit weight, stone weight, soluble solids content, pH, total acid content), morphological (crown volume, trunk diameter, current season growth), and phonological (first bloom, full bloom) characteristics (P≤0.01) was observed. Genotype SH7 had the highest fruit weight (9.27 g), while SH1 had the lowest fruit and stone weights (4.51 g, 0.38 g, respectively). Crown volume ranged between 16.53 m3 (SH23) and 32.67 m3 (SH13) in Siah Mashhad sweet cherry genotypes. Current season vegetative growth ranged between 45.66 and 58.00 cm. Results also showed that genotypes SH21 and SH20 had the lowest and highest trunk diameter (93.65 mm and 161.99 mm, respectively). Our results indicate there is wide variation in flowering, growth, and fruit characteristics of Siah Mashhad sweet cherry genotypes

Seed and oil yields, their components, and the relationships among trait performance were determined in 25 genotypes of winter type oilseed rape (Brassica napus L.). The experiment was carried out at the Agricultural and Natural Resources Research Center of East Azerbaijan, Iran, in two consecutive growing seasons 2009-10 and 2010-11. Significant differences were observed in plant height, number of pods per plant, number of seeds per pod, 1000-seed weight, harvest index, and seed and oil yield. Cluster analysis divided the genotypes into two groups based on the studied traits. One group consisted of 16 genotypes with low and the other included 9 genotypes with high seed and oil yield. Based on observations, genotypes SW102, HW101, HW111, L62, L72, L139, SW104, Karaj1, and Karaj2 showed high seed and oil yields and would therefore be suitable for the Tabriz plain and areas with similar conditions and for selecting genotypes tolerant to environmental stress. A positive correlation was found between plant height and number of seeds per pod, and seed and oil yields. Number of pods per plant contributed more to seed yield among seed yield components. Harvest index and 1000-seed weight had the highest and the lowest indirect effects on oil yield, respectively. It appears that harvest index and plant height are important features for selecting winter type oilseed rape genotypes for Tabriz plain and areas with similar conditions

Fifteen microsatellite markers were employed to evaluate genetic relationships among different Iranian species of Crocus spp. (C. sativus, C. haussknechtii, C. cancellatus, C. speciosus, and C. caspius) from ten geographical regions (Ghaen, Gonabad, Estahban, Ferdows, Veresk, Reno, Ali abad, Kali abad, Neka, and Eslam abad). Of these, 12 primers revealed polymorphism among Crocus spp. Average polymorphism information content (PIC) and genetic diversity valueswere 0.33 and 0.41, respectively. Cluster analysis using the neighbor-joining (NJ) algorithm based on Nei’s genetic distance separated all the cultivated clonesfrom wild ones and differentiated all species. Utilizing principal coordinate analysis (PCoA) and analysis of molecular variance (AMOVA), significant heterogeneity was observed within Crocus species. Based on the genetic distance (0.0311) andfixation index (FST=0.33, P>0.05) between Estahban (29° 12'' N and 54° 03'' E) and Ferdows (34° 01'' N and 58° 16'' E), it seems that accessions from Estahbanmay have originated from Ferdows genotypes. Indeed, results revealed that C. hausskntchii is the closest wild species to cultivated ones