Search

Wheat resistance to Fusarium head blight (FHB) has often been associated with some undesirable agronomic traits. To study the relationship between wheat FHB resistance and agronomic traits, we constructed a linkage map of single nucleotide polymorphisms (SNPs) using an F6:8 population from G97252W × G97380A. The two hard winter wheat parents showed contrasts in FHB resistance, plant height (HT), heading date (HD), spike length (SL), spike compactness (SC), kernel number per spike (KNS), spikelet number per spike (SNS), thousand-grain weight (TGW) and grain size (length and width). Quantitative trait locus (QTL) mapping identified one major QTL (QFhb.hwwg-2DS) on chromosome arm 2DS for the percentage of symptomatic spikelets (PSS) in the spike, deoxynivalenol (DON) content and Fusarium damaged kernel (FDK). This QTL explained up to 71.8% of the phenotypic variation for the three FHB-related traits and overlapped with the major QTL for HT, HD, SL, KNS, SNS, TGW, and grain size. QTL on chromosome arms 2AL, 2DS, 3AL and 4BS were significant for the spike and grain traits measured. G97252W contributed FHB resistance and high SNS alleles at QFhb.hwwg-2DS, high KNS alleles at the QTL on 2AL and 2DS, and high TGW and grain size alleles at QTL on 3AL; whereas G97380A contributed high TGW and grain size alleles at the QTL on 2AL and 2DS, respectively, and the high KNS allele at the 4BS QTL. Combining QFhb.hwwg-2DS with positive alleles for spike and grain traits from other chromosomes may simultaneously improve FHB resistance and grain yield in new cultivars. [ABSTRACT FROM AUTHOR]

Tomato is an edible and useful vegetable. Navel rot disease and low light stress are the problem in tomato cultivation. Tomato breeding is a potential cheap solution but takes longer time. Grafting technology provides instant solution like cultivating sensitive tomato (scion) grafted on resistant rootstock on non-optimal environmental conditions. DNA methylation of grafted plants might help to adapt to the adverse conditions and has become a hot point in researches concerning vegetable breeding. In this research, disease-resistant tomato cultivar "1221" was used as rootstock, while disease-sensitive tomato cultivar "Money Maker (MM)" was used as scion. After grafting, changes of genomic global DNA methylation were investigated through MSAP analysis. According to MSAP analysis, alterations of degree of DNA methylation patterns were observed, which might help graft hybrids to adapt in response to the internal and external stimuli. [ABSTRACT FROM AUTHOR]

Soil salinity among other abiotic stresses is a major threat to cultivated land. Breeding salt tolerant cultivars has always been thought to be an effective and cheaper way to overcome salinity problem. Salt tolerant and salt sensitive wheat accessions were hybridized to develop genetic material to investigate inheritance of salt tolerance based on early seedling, adult plant and physiological responses. Salt tolerance in low salinity appeared to be a complex polygenic trait. However, genetic models for most responses were poor fit in high salinity and suggested further investigations. Differences in gene expressions in different NaCl concentrations appeared to be due to different gene regulation or interaction and/or involvement of additional or hidden genes. Both additive and non-additive gene effects required to be considered while designing of breeding programme for improving salt tolerance in wheat and in the statistical model used to find QTL for the salt tolerance. This QTL couple with recurrent selection for specific combining ability of the 4WLRG/1-8 with an excellent cultivar of wheat appears to be a good salt tolerant breeding strategy. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]