1.
Corn silk decoction for blood lipid in patients with angina pectoris: A systematic review and meta-analysis.
Shi, S, Yu, B, Li, W, Shan, J, Ma, T
Phytotherapy research : PTR. 2019;(11):2862-2869
Abstract
The aims of this study were to evaluate the efficacy of corn silk decoction on lipid profile in patients with angina pectoris. PubMed, Cochrane, Embase, Google Scholar, Chongqing VIP Chinese Science and Technology Periodical Database, China National Knowledge Infrastructure, and Wanfang database were searched up to January 2019 for randomized controlled trials that assessed the impact of corn silk decoction on total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol in patients with angina pectoris. Study evaluation and synthesis methods were in accordance with the Cochrane Handbook, and data were analyzed using Review Manager (version 5.3) software. Random effects model was applied in this systematic review and meta-analysis to compensate for potential heterogeneity among the included studies. A total of four randomized controlled trials were eligible for meta-analysis. Pooled results of these studies indicated that corn silk decoction might improve high-density lipoprotein cholesterol and reduce total cholesterol, triglycerides, and low-density lipoprotein cholesterol in patients with angina pectoris. Subgroup analyses showed that corn silk decoction or modified corn silk decoction plus conventional pharmaceutical treatment could have favorable effects on blood lipids. However, the lack of blinding in most studies may have led to overestimation of these effects. Further studies with better design are needed to confirm these findings.
2.
What is the agronomic potential of biofertilizers for maize? A meta-analysis.
Schmidt, JE, Gaudin, ACM
FEMS microbiology ecology. 2018;(7)
Abstract
Biofertilizers are promoted as a strategy for sustainable intensification of agriculture, but their efficacy varies widely among published studies and it is unclear whether they deliver the promised benefits. Studies are commonly conducted under controlled conditions prior to deployment in the field, yet the predictive value of such studies for field-scale productivity has not been critically examined. A meta-analysis was conducted using a novel host crop-specific approach to evaluate the agronomic potential of bacterial biofertilizers for maize. Yield increases tended to be slightly higher and more variable in greenhouse studies using field soil than in the field, and greenhouse studies poorly predicted the influence of moderating climate, soil and taxonomic variables. We found greater efficacy of Azospirillum spp. and lower efficacy of Bacillus spp. and Enterobacter spp. under field conditions. Surprisingly, biofertilizer strains with confirmed plant-growth-promoting traits such as phosphorus solubilization, nitrogen fixation and phytohormone production in vitro were associated with lower yields in the field than strains not confirmed to possess these traits; only 1-aminocyclopropane-1-carboxylate deaminase synthesis increased yields. These results indicate the need for a novel biofertilizer development framework that integrates information from native soil microbial communities and prioritizes field validation of results.
3.
Genome-wide meta-analysis of maize heterosis reveals the potential role of additive gene expression at pericentromeric loci.
Thiemann, A, Fu, J, Seifert, F, Grant-Downton, RT, Schrag, TA, Pospisil, H, Frisch, M, Melchinger, AE, Scholten, S
BMC plant biology. 2014;:88
Abstract
BACKGROUND The identification of QTL involved in heterosis formation is one approach to unravel the not yet fully understood genetic basis of heterosis - the improved agronomic performance of hybrid F1 plants compared to their inbred parents. The identification of candidate genes underlying a QTL is important both for developing markers and determining the molecular genetic basis of a trait, but remains difficult owing to the large number of genes often contained within individual QTL. To address this problem in heterosis analysis, we applied a meta-analysis strategy for grain yield (GY) of Zea mays L. as example, incorporating QTL-, hybrid field-, and parental gene expression data. RESULTS For the identification of genes underlying known heterotic QTL, we made use of tight associations between gene expression pattern and the trait of interest, identified by correlation analyses. Using this approach genes strongly associated with heterosis for GY were discovered to be clustered in pericentromeric regions of the complex maize genome. This suggests that expression differences of sequences in recombination-suppressed regions are important in the establishment of heterosis for GY in F1 hybrids and also in the conservation of heterosis for GY across genotypes. Importantly functional analysis of heterosis-associated genes from these genomic regions revealed over-representation of a number of functional classes, identifying key processes contributing to heterosis for GY. Based on the finding that the majority of the analyzed heterosis-associated genes were addtitively expressed, we propose a model referring to the influence of cis-regulatory variation on heterosis for GY by the compensation of fixed detrimental expression levels in parents. CONCLUSIONS The study highlights the utility of a meta-analysis approach that integrates phenotypic and multi-level molecular data to unravel complex traits in plants. It provides prospects for the identification of genes relevant for QTL, and also suggests a model for the potential role of additive expression in the formation and conservation of heterosis for GY via dominant, multigenic quantitative trait loci. Our findings contribute to a deeper understanding of the multifactorial phenomenon of heterosis, and thus to the breeding of new high yielding varieties.
4.
QTL mapping in three tropical maize populations reveals a set of constitutive and adaptive genomic regions for drought tolerance.
Almeida, GD, Makumbi, D, Magorokosho, C, Nair, S, Borém, A, Ribaut, JM, Bänziger, M, Prasanna, BM, Crossa, J, Babu, R
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik. 2013;(3):583-600
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Abstract
Despite numerous published reports of quantitative trait loci (QTL) for drought-related traits, practical applications of such QTL in maize improvement are scarce. Identifying QTL of sizeable effects that express more or less uniformly in diverse genetic backgrounds across contrasting water regimes could significantly complement conventional breeding efforts to improve drought tolerance. We evaluated three tropical bi-parental populations under water-stress (WS) and well-watered (WW) regimes in Mexico, Kenya and Zimbabwe to identify genomic regions responsible for grain yield (GY) and anthesis-silking interval (ASI) across multiple environments and diverse genetic backgrounds. Across the three populations, on average, drought stress reduced GY by more than 50 % and increased ASI by 3.2 days. We identified a total of 83 and 62 QTL through individual environment analyses for GY and ASI, respectively. In each population, most QTL consistently showed up in each water regime. Across the three populations, the phenotypic variance explained by various individual QTL ranged from 2.6 to 17.8 % for GY and 1.7 to 17.8 % for ASI under WS environments and from 5 to 19.5 % for GY under WW environments. Meta-QTL (mQTL) analysis across the three populations and multiple environments identified seven genomic regions for GY and one for ASI, of which six mQTL on chr.1, 4, 5 and 10 for GY were constitutively expressed across WS and WW environments. One mQTL on chr.7 for GY and one on chr.3 for ASI were found to be 'adaptive' to WS conditions. High throughput assays were developed for SNPs that delimit the physical intervals of these mQTL. At most of the QTL, almost equal number of favorable alleles was donated by either of the parents within each cross, thereby demonstrating the potential of drought tolerant × drought tolerant crosses to identify QTL under contrasting water regimes.