Genetic progress in stem lodging resistance of the dominant wheat cultivars adapted to Yellow-Huai River Valleys Winter Wheat Zone in China since 1964

Analysis of genetic progress for lodging-related traits provides important information for further improvement of lodging resistance.Forty winter wheat cultivars widely grown in the Yellow-Huai River Valleys Winter Wheat Zone(YHWZ)of China during the period of 1964–2015 were evaluated for several lodging-related traits in three cropping seasons.Plant height,height at center of gravity,length of the basal second internode,and lodging index decreased significantly in this period,and the average annual genetic gains for these traits were–0.50 cm or–0.62%,–0.27 cm or–0.60%,–0.06 cm or–0.63%,and–0.01 or–0.94%,respectively.Different from other traits,stem strength showed a significant increasing trend with the breeding period,and the annual genetic gains were 0.03 N or 0.05%.Correlation analysis showed that lodging index was positively correlated with plant height,height at center of gravity,and length of the basal second internode,but negatively correlated with stem strength.Meanwhile,significantly positive correlations were observed between plant height,height at center of gravity,and length of the basal first and second internodes.By comparison with the wild types,dwarfing genes had significant effects on all lodging-related traits studied except for length of the basal first internode and stem strength.Principle component analysis demonstrated that plant height and stem strength were the most important factors influencing lodging resistance.Clustering analysis based on the first two principle components further indicated the targets of wheat lodging-resistant breeding have changed from reducing plant height to strengthening stem strength over the breeding periods.This study indicates that the increase of stem strength is vital to improve lodging resistance in this region under the high-yielding condition when plant height is in an optimal range.

Genetic and Breeding Progress Analysis on Five Pure Lines of Dahen Broiler

To timely modify breeding scheme and improve selection efficiency of Dahen broiler, genetic and breeding progress analysis on five pure lines was conducted. The results showed that the selection on breeding goal traits of each line was effective since 14 generations, especially the selection on growth traits did not cause adverse influence on reproductive performance. After the 6^ th generation, main performances of each line maintained in higher level, but the breeding progress obviously declined. It illustrated that current breeding means was effective for maintaining and consolidating breeding goal traits of Dahen broiler, and it should timely adjust breeding scheme to obtain more genetic progress.

Genetic and Breeding Progress Analysis on S06M Line of Dahen Broiler

The genetic and breeding progress of Dahen S06M line was analyzed, in order to improve the selection efficiency. The results showedthat six generations of selection was effective in selecting main characters of S06M line, especially the selection of growth rate had no adverse effecton reproductive performance. All indicators of reproductive performance were improved in varying degrees during breeding, particularly the egg production at 68 weeks of age. The breeding progress of main target traits significantly slowed down after the second generation, but they still maintained at higher levels and the characters of S06M tended to be stable.

Cotton germplasm improvement and progress in Pakistan

Cotton(Gossypium spp.)contributes significantly to the economy of cotton-producing countries.Pakistan is the fourth-largest producer of cotton after China,the USA and India.The average yield of cotton is about 570.99 kg.hm^(−2) in Pakistan.Climate change and different biotic stresses are causing reduction in cotton production.Transgenic approaches have unique advantage to tackle all these problems.However,how to confer permanent resistance in cotton against insects through genetic modification,is still a big challenge to address.Development of transgenic cotton has been proven to be effective.But its effectiveness depends upon several factors,including heterogeneity,seed purity,diffusion of varieties,backcrossing and ethical concerns.Cotton biotechnology was initiated in Pakistan in 1992–1993 with a focus on acquiring cotton leaf curl virus(CLCuV)-resistant insect-resistant,and improving fiber quality.This review summarizes the use of molecular markers,QTLs,GWAS,and gene cloning for cotton germplasm improvement,particularly in Pakistan.

The interaction of genetics and environmental toxicants in amyotrophic lateral sclerosis:results from animal models

Amyotrophic lateral sclerosis（ALS） is a devastating neurodegenerative disease that results in the progressive death of motor neurons, leading to paralysis and eventual death. There is presently no cure for ALS, and only two drugs are available, neither of which provide significant extension of life. The wide variation in onset and progression of the disease, both in sporadic and even in strongly penetrant monogenic familial forms of ALS, indicate that in addition to background genetic variation impacting the disease process, environmental exposures are likely contributors. Epidemiological evidence worldwide implicates exposures to bacterial toxins, heavy metals, pesticides, and trauma as probable environmental factors. Here, we review current advances in gene-environment interactions in ALS animal models. We report our recent discoveries in a zebrafish model of ALS in relation to exposure to the cyanobacterial toxin BMAA, and discuss several results from mouse models that show interactions with exposure to mercury and statin drugs, both leading to acceleration of the disease process. The increasing research into this combinatorial gene-environment process is just starting, but shows early promise to uncover the underlying biochemical pathways that instigate the initial motor neuron defects and lead to their rapidly progressive dysfunction.