QTL Mapping for Adult Plant Resistance to Powdery Mildew in Italian Wheat cv. Strampelli

The Italian wheat cv.Strampelli displays high resistance to powdery mildew caused by Blumeria graminis f.sp.tritici.The objective of this study was to map quantitative trait loci(QTLs) for resistance to powdery mildew in a population of 249 F 2:3 lines from Strampelli/Huixianhong.Adult plant powdery mildew tests were conducted over 2 yr in Beijing and 1 yr in Anyang and simple sequence repeat(SSR) markers were used for genotyping.QTLs Qpm.caas-3BS,Qpm.caas-5BL.1,and Qpm.caas-7DS were consistent across environments whereas,Qpm.caas-2BS.1 found in two environments,explained 0.4-1.6,5.5-6.9,27.1-34.5,and 1.0-3.5% of the phenotypic variation respectively.Qpm.caas-7DS corresponded to the genomic location of Pm38/Lr34/Yr18.Qpm.caas-4BL was identified in Anyang 2010 and Beijing 2011,accounting for 1.9-3.5% of phenotypic variation.Qpm.caas-2BS.1 and Qpm.caas-5BL.1 contributed by Strampelli and Qpm.caas-3BS by Huixianhong,seem to be new QTL for powdery mildew resistance.Qpm.caas-4BL,Qpm.caas-5BL.3,and Qpm.caas-7DS contributed by Strampelli appeared to be in the same genomic regions as those mapped previously for stripe rust resistance in the same population,indicating that these loci conferred resistance to both stripe rust and powdery mildew.Strampelli could be a valuable genetic resource for improving durable resistance to both powdery mildew and stripe rust in wheat.     

Parental chromosome differentiation in citrangequat [Fortunella sp. × (Citrus sinensis × Poncirus trifoliata)] using CMA banding patterns

The efficiency of chromomycin A₃ (CMA) staining was examined for parental chromosome differentiation in citrange [Citrus sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.] and citrangequat (Fortunella sp. × citrange). All of the accessions analyzed had the same chromosome number of 2n = 18. CMA staining revealed six characteristic banding patterns on the basis of the number and position of CMA positive bands (CMA⁺) as follows; A: two terminal and one proximal band, B: one terminal and one proximal band, C: two terminal bands, D: one terminal band, E: no band, and F: one proximal band. Chromosome CMA banding patterns of the accessions were 1A + 1B + 2C + 13D + 1F in Fortunella margarita, 2B + 2C + 7D + 7E in ‘Fukuhara’ orange, 2B + 10D + 6E in Poncirus trifoliata, 1B + 1C + 10D + 6E in citrange and 1A + 1C + 11D + 4E + 1F in citrangequat. The results of this study confirmed the intergeneric and tri-generic hybridity of citrange and citrangequat, respectively.     

Monitoring Nitrogen Dioxide Levels in Urban Areas in Rawalpindi, Pakistan

Nitrogen dioxide is an important gaseous air pollutant. It plays a major role in atmospheric chemistry, particularly in the formation of secondary air pollutants, and contributes to environmental acidification. A comprehensive assessment of NO₂ levels in the atmosphere is required for developing effective strategies for control of air pollution and air quality improvement. Air pollution is a serious problem in all major cities of Pakistan and needs to be addressed to minimize detrimental effects on human health and urban vegetation. In this research, we focused on the monitoring of NO₂ levels in the urban environment of Rawalpindi city. Because of the lack of expensive continuous sampling devices and to get a good spatial coverage of the NO₂ concentrations in the study area, NO₂ passive samplers were exposed at 42 different sites within the city limits of Rawalpindi from January to December, 2008. Samplers were exchanged every 10 days and the associated meteorological conditions like temperature, wind speed, rainfall and relative humidity were also monitored. The average NO₂ concentration was found to be 27.46?±?0.32 ppb. The highest values of NO₂ were measured near to main roads and educational institutions due to intense flow of road vehicles. Moreover, the study showed that the values obtained for NO₂ for all sampling points exceeded the annual limit value set by World Health Organization. So, this is very important to take different steps to control this before it becomes a serious hazard for people living in those areas.     

Mutation of alpha-tubulin genes in trifluralin-resistant water foxtail (Alopecurus aequalis)

BACKGROUND: Trifluralin‐resistant biotypes of water foxtail (Alopecurus aequalis) have been identified in wheat fields from northern Kyushu, Japan. Water foxtail is a winter‐annual grassy weed, causing substantial crop losses. This study reports on mutation in α‐tubulin (TUA) genes from water foxtail, the site of action of trifluralin. RESULTS: Two trifluralin‐sensitive (S) Chikugo and Ukiha biotypes and four trifluralin‐resistant (R) Asakura‐1, Asakura‐2, Tamana and Tosu biotypes of water foxtail were used for herbicide resistance analysis. R biotypes showed 5.7–30.7‐fold trifluralin resistance compared with the S biotypes. No differences in the uptake and translocation of ¹⁴C‐trifluralin were observed between Chikugo (S) biotype and Asakura‐1 (R) biotype. Most of the ¹⁴C detected in the plant material was in the root tissue, and no substantial increases were noted in shoot tissues. Comparative TUA sequence analysis revealed two independent single amino acid changes: change of Val into Phe at position 202 in TUA1 and change of Leu into Met at position 125 in TUA3 in Asakura‐1 biotype. In the Tamana (R) biotype, two amino acid changes of Leu to Phe at position 136 and Val to Phe at position 202 were observed in the predicted amino acid sequence of TUA1, compared with Chikugo (S) biotype. CONCLUSION: The results provide preliminary molecular explanation for the resistance of water foxtail to trifluralin, a phenomenon that has arisen as a result of repeated exposure to this class of herbicide. This is the first report of α‐tubulin mutation in water foxtail and for any Alopecurus species reported in the literature. Copyright © 2011 Society of Chemical Industry