Template-Type: ReDIF-Article 1.0 Author-Name: Allah Bakhsh Author-Workplace-Name: Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan Author-Name: Kamran Shahzad Author-Workplace-Name: Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan Author-Name: Tayyab Husnain Author-Workplace-Name: Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan Title: Variation in the spatio-temporal expression of insecticidal genes in cotton Abstract: The most significant breakthrough in plant biotechnology is the development of the techniques to transform genes from unrelated sources into commercially important crop plants to develop resistance against targeted insect pests. The spatio-temporal expression of insecticidal genes in transgenic cotton varies with plant age, plant parts and environmental conditions. The understanding of this temporal and spatial variation in efficacy and the resulting mechanisms is essential for cotton protection and production. This review summarizes variations in the efficacy of introduced insecticidal genes in cotton crop. The factors contributing to the variability of endotoxins have also been highlighted. The reduction in Bt protein biosynthesis in late-season cotton tissues could be attributed to the overexpression of the Bt gene at earlier stages, which leads to gene regulation at post-transcription levels and consequently results in gene silencing at a later stage. Methylation of the promoter may also play a role in the declined expression of endotoxin proteins. In genetically modified crops several environmental factors have been reported to affect the expression of transgenes. Among environmental factors nitrogen metabolism, inhibition of synthesis, degradation, remobilization and high temperature are attributable to the quantitative reduction in Bt proteins. Applying plant growth regulators or protein enhancers such as ChaperoneTM may improve Bt cotton efficacy through enhancing the synthesis of proteins. Also some agronomic practices such as nitrogen fertilization and timely irrigation favour the endotoxin expression. Thus, variations in the efficacy of insecticidal genes in transgenic cotton and the involved mechanisms need to be understood fully so as to plan rational resistance management strategies to retard the rate of resistance development and to control target pests effectively by enhancing the endotoxin expression through genetic or agronomic management. Keywords: efficacy, spatio-temporal expression, transgenic Bt cotton Journal: Czech Journal of Genetics and Plant Breeding Pages: 1-9 Volume: 47 Issue: 1 Year: 2011 DOI: 10.17221/131/2010-CJGPB File-URL: http://cjgpb.agriculturejournals.cz/doi/10.17221/131/2010-CJGPB.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjg-201101-0001.txt Handle: RePEc:caa:jnlcjg:v:47:y:2011:i:1:id:131-2010-CJGPB Template-Type: ReDIF-Article 1.0 Author-Name: Alena Hanzalová Author-Workplace-Name: Crop Research Institute, Prague-Ruzyně, Czech Republic Author-Name: Pavel Bartoš Author-Workplace-Name: Crop Research Institute, Prague-Ruzyně, Czech Republic Title: Resistance of triticale to wheat leaf rust (Puccinia triticina) Abstract: Reactions of winter triticale cultivars mostly from central Europe to recent and old leaf rust isolates were tested in the greenhouse. In one trial 20 cultivars were tested with 8 leaf rust isolates, collected recently from official wheat and triticale trials in the Czech Republic and Slovakia. In another trial 15 cultivars were tested with 6 old leaf rust isolates, used to identify leaf rust resistance genes in wheat. The cultivars Cando, Hortenso and Tricolor, registered in the Czech Republic, were resistant to the majority of the recent isolates. The Hungarian cultivar Tatra was resistant to all the recent isolates. The old leaf rust isolates were virulent only to a few of the triticale cultivars. Randomly selected isolates from wheat and triticale were tested on triticale cultivars and on Thatcher near isogenic lines with different Lr genes. On average, leaf rust isolates from triticale were virulent to a higher number of triticale cultivars than isolates collected from wheat and vice versa. Keywords: Puccinia triticina, triticale, variety resistance, wheat leaf rust Journal: Czech Journal of Genetics and Plant Breeding Pages: 10-16 Volume: 47 Issue: 1 Year: 2011 DOI: 10.17221/100/2010-CJGPB File-URL: http://cjgpb.agriculturejournals.cz/doi/10.17221/100/2010-CJGPB.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjg-201101-0002.txt Handle: RePEc:caa:jnlcjg:v:47:y:2011:i:1:id:100-2010-CJGPB Template-Type: ReDIF-Article 1.0 Author-Name: Sara Tale Ahmad Author-Workplace-Name: Agricultural Biotechnology Department, Imam Khomeini International University, Qazvin, Iran Author-Name: Raheem Haddad Author-Workplace-Name: Agricultural Biotechnology Department, Imam Khomeini International University, Qazvin, Iran Title: Study of silicon effects on antioxidant enzyme activities and osmotic adjustment of wheat under drought stress Abstract: The effect of silicon (Si) was investigated on the major antioxidant enzyme activities including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), relative water content (RWC), chlorophyll and soluble protein contents, proline (Pro) and glycine betaine (GB) accumulation in three different growth stages (2nd, 4th leaf and tillering stages) of wheat (Triticum aestivum L.) plants under drought stress. The experiment was performed in a completely randomized design for three treatments including control, drought and Si-drought (2mM silicate sodium/kg) with three replications in a greenhouse. The results indicated that Si partially offset the negative impacts of drought stress increasing the tolerance of wheat by rising Pro and GB accumulation and soluble protein content. Compared with the plants treated with drought, applied Si significantly enhanced the activities of SOD, CAT, APX and POD. In contrast, drought stress caused a considerable decrease in RWC, chlorophyll and soluble protein contents. This Si effect was time-dependent and became stronger in the tillering stage. The results of the present experiment coincided with the conclusion that Si alleviates water deficit of wheat by preventing the oxidative membrane damage and may be associated with plant osmotic adjustment. Keywords: drought, osmotic adjustment, oxidative stress, silicon, wheat Journal: Czech Journal of Genetics and Plant Breeding Pages: 17-27 Volume: 47 Issue: 1 Year: 2011 DOI: 10.17221/92/2010-CJGPB File-URL: http://cjgpb.agriculturejournals.cz/doi/10.17221/92/2010-CJGPB.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjg-201101-0003.txt Handle: RePEc:caa:jnlcjg:v:47:y:2011:i:1:id:92-2010-CJGPB Template-Type: ReDIF-Article 1.0 Author-Name: Hana Jakešová Author-Workplace-Name: Red Clover and Grass Breeding Hladké Životice, Czech Republic Author-Name: Jana Řepková Author-Workplace-Name: Department of Experimental Biology, Masaryk University in Brno, Czech Republic Author-Name: David Hampel Author-Workplace-Name: Central Institute for Supervising and Testing in Agriculture, Brno, Czech Republic Author-Name: Lydie Čechová Author-Workplace-Name: Central Institute for Supervising and Testing in Agriculture, Brno, Czech Republic Author-Name: Jan Hofbauer Author-Workplace-Name: Agricultural Research Troubsko, Czech Republic Title: Variation of morphological and agronomic traits in hybrids of Trifolium pratense × T. medium and a comparison with the parental species Abstract: Trifolium pratense L. is a high-yielding and high-quality fodder crop. However, it shows low persistence, which may be overcome by hybridisation with species that produce rhizomes. Hybrids between T. pratense L. and T. medium L. were previously obtained by embryo rescue. The aim of this study was to evaluate 16 characteristics (stem weight, stem length, internode number, length/width ratio of a central leaflet of the trifoliate leaf on the 4th internode, stem thickness on the 4th internode, average leaf area of the trifoliate leaf, weight of dry plant, plant length, stem and head number per plant, head number per stem, seed weight per plant, seed weight per head and dry matter per stem) in the hybrid plants derived from F1 hybrids and in both parental genotypes. The characteristics were evaluated in 500, 745 and 112 hybrid plants in the years 2006, 2008 and 2009, respectively. The significance of the morphological differences was determined by the general linear model and generalised linear model with Poisson distribution with two factors, genotype and year. Some of the examined traits were intermediate in the hybrids. There were significant differences between the hybrids and T. pratense in nearly all the analysed characteristics, except for the following ones: length/width ratio of a central leaflet of the trifoliate leaf on the 4th internode under the top head, plant weight and head number per plant. The stem number per plant was significantly higher in the hybrids compared to both parental species, which could have a positive impact on the yield. Short rhizomes were observed in the hybrids after the harvest of plants in the second harvest year. The stability of this trait and its impact on the perenniality of the hybrids will be investigated in the next years. Keywords: interspecific hybrids, morphological traits, persistence, red clover, rhizomes, zigzag clover Journal: Czech Journal of Genetics and Plant Breeding Pages: 28-36 Volume: 47 Issue: 1 Year: 2011 DOI: 10.17221/2/2011-CJGPB File-URL: http://cjgpb.agriculturejournals.cz/doi/10.17221/2/2011-CJGPB.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjg-201101-0004.txt Handle: RePEc:caa:jnlcjg:v:47:y:2011:i:1:id:2-2011-CJGPB Template-Type: ReDIF-Article 1.0 Author-Name: Pavel Mařík Author-Workplace-Name: Research Centre SELTON, Stupice, Czech Republic Author-Name: Zdenek Šnejdar Author-Workplace-Name: Research Centre SELTON, Stupice, Czech Republic Author-Name: Pavel Matušinsky Author-Workplace-Name: Agrotest fyto, Kroměříž, Czech Republic Title: Expression of resistance to Ramularia leaf spot in winter barley cultivars grown in conditions of the Czech Republic Abstract: The fungus Ramularia collo-cygni is increasingly important as the causal agent of Ramularia leaf spot (RLS), a novel leaf spot disease of barley. The work aimed to identify gene resources suitable for developing new breeding lines of winter barley with improved resistance. During the first experimental period (2001-2005), RLS incidence was monitored in 711 cultivars and advanced breeding lines. Differences were detected in the intensity of symptomatic expression, but no material showed high resistance. During the second experimental period (2006-2009), response to natural RLS infection was evaluated in 19 winter barley cultivars (12 six-row and 7 two-row) registered in the Czech Republic. Highest susceptibility was detected in 6-row cvs. Luran, Laverda and Wendy while cvs Breunskylie (2-row), Merlot and Highlight (both 6-row) showed relatively lower disease incidence. High resistance was not detected. On average, 2-row cultivars showed lower intensity than 6-row cultivars and significant variation was observed among years. Keywords: cultivar resistance, natural infection, Ramularia collo-cygni Journal: Czech Journal of Genetics and Plant Breeding Pages: 37-40 Volume: 47 Issue: 1 Year: 2011 DOI: 10.17221/34/2010-CJGPB File-URL: http://cjgpb.agriculturejournals.cz/doi/10.17221/34/2010-CJGPB.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjg-201101-0005.txt Handle: RePEc:caa:jnlcjg:v:47:y:2011:i:1:id:34-2010-CJGPB Template-Type: ReDIF-Article 1.0 Author-Name: E. Tejklová Author-Name: M. Bjelková Title: Low-linolenic linseed (Linum usitatissimum L.) Allan Journal: Czech Journal of Genetics and Plant Breeding Pages: 41-42 Volume: 47 Issue: 1 Year: 2011 DOI: 10.17221/123/2010-CJGPB File-URL: http://cjgpb.agriculturejournals.cz/doi/10.17221/123/2010-CJGPB.html File-Format: text/html Handle: RePEc:caa:jnlcjg:v:47:y:2011:i:1:id:123-2010-CJGPB Template-Type: ReDIF-Article 1.0 Author-Name: R. Šafaříková Title: List of field crop varieties registered in the Czech Republic in 2010 Journal: Czech Journal of Genetics and Plant Breeding Pages: 43-44 Volume: 47 Issue: 1 Year: 2011 DOI: 10.17221/13/2011-CJGPB File-URL: http://cjgpb.agriculturejournals.cz/doi/10.17221/13/2011-CJGPB.html File-Format: text/html Handle: RePEc:caa:jnlcjg:v:47:y:2011:i:1:id:13-2011-CJGPB