مجله زیست فناوری گیاهان زراعی
پیاپی 9 (بهار 1394)

Seed germination (capacity, time, and synchronization) is a manifest characteristic of the standard germination test of a cultivated variety. In order to identify genomic regions associated with seed germination, 149 bread wheat recombinant inbred lines and their parents RojoYecora and No. 49 were conducted in an alpha lattice design with two replications at the University of Mahabad during 2013-14, under normal and moisture stress conditions. Different traits including index of germination speed, final germination percentage, germination speed, germination rate, and average daily germination were measured. In this study, 340 pairs of microsatellite primers were used to determine the parental polymorphism. Furthermore, 7 retrotransposon-based markers on LTR regions of barely retrotransposons, and their twenty-eight combinations at IRAP technique, as well as, 63 combination of this primer with anchored ISSR primers at REMAP technique were used for population screening. QTL analysis using composite interval mapping (CIM) for each trait in each environment and mean of two environments were accomplished. For all studied traits, transgressive segregation was observed. In general, eleven QTLs were detected for all traits. Total phenotypic variance explained by these QTLs varied from 11.82 to 21.42 percent. The highest LOD value for QTL controlling germination speed (LOD =6.65) was obtained on chromosome 4BQSg-Normal. The results revealed that QTLs of index of germination rate and germination speed related to the quantity and quality of seed germination had desirable performance in all three environments. However, detected stable and cluster QTLs may be used in marker assisted selection (MAS) programs.

Since the economic value of cultivars depends on different characteristics, thus procedure of selection for several traits to maximizing the economic value always has been considered by plant breeders. Detailed knowledge on genetic behavior and association between economic traits will help breeders to improve plant populations. In this study, 12 retrotransposons-based primers (7 IRAP and 5 REMAP primers) and general and mixed linear models (GLM and MLM) were used to identify molecular markers associated to 9 seed related important traits including oil yield, oil percentage, protein yield, protein percentage, grain length, grain diameter, grain weight, dehulled kernel weight, percentage of dehulled kernel weight to whole grain in 48 confectionery sunflower landraces under normal irrigation, mild and severe drought stress conditions. By applying Bayesian model, the whole confectionery sunflower populations were classified into two sub-populations. Based on general linear model, 2, 5 and 12 loci and through mixed linear model 2, 5 and 11 loci showed significant (P)

The objective of the present study was to optimize fast production of enriched biocompost from sugarcane bagasse using native effective microorganisms and also other available materials. Four native bacterial strains with high hydrolase activities were produced at their optimized fermentation conditions. The compost production experiments were performed in the format of completely randomized design (CRD). Bagasse, filter cake and vinasses were used as base materials in all treatments (exception for control). The microbial cocktail (106-107 cells/g waste), chicken manure or urea was used as improvers. The treatments were as follows: T1- chicken manure and microbial cocktail, T2-chicken manure, T3- urea and micronial cocktail, T4- urea, and T5- control (only bagasse). The maximum temperature increase (upo to 58°C), the maximum C/N ratio (15.9) and EC reductions was observed for T1, followed by T2. The highest phosphorous (1.1%), potassium (1%), total nitrogen (2%) and nitrate (210 mg/kg) and also the lowest ammonia (67 mg/kg) contents were observed in T1. Evaluation of the phytotoxicity effects of the produced composts on cress (Lepidium sativum) seeds germination showed that the fastest and maximum germination was observed for T1 and T2, respectively. The wheats cultured on the compost produced from T1 showed significantly higher height, and fresh and dry weights compared to other treatments. So, the results of the present study showed that the presence of microbial strains ans chicken manure enhanced a significant reduction inprocess period, compost maturity and finally production of high quality compost from sugarcane wastes.

Silicon is accounted as one of the elements that induces resistance to different kinds of stresses especially drought stress in plants. In this study, the effect of silicon was analyzed on the activity of antioxidant enzymes Catalase, Ascorbate peroxidase and Superoxide dismutase and also related genes expression pattern and H2O2 content on two varsities, NIMROOZ (drought resistant) and GORGAN (semi-resistant) under three treatments of drought, silicon-drought and control in a completely randomized design with three replications in four leaf developmental stage in a green house. Based on the results of factorial test, catalase activity was decreased in semi-sensitive varity and silicon treatment increased such activity in both varieties under drought stress. While the activity of two other enzymes (Ascorbat peroxidase and Superoxide dismutase) was increased under drought stress and silicon treatment intensified their activity in comparison with control. Their pattern of gene expression changed in a similar way of enzyme activity. It might be concluded that, the role of silicon in enhancing drought tolerance in barley plant is because of increasing activity of antioxidant enzymes and expression of stress responsible genes, and therefore, causes reduction in activity of reactive oxygen spices produced under drought stress.