Genome-wide association mapping and genomic prediction of stalk rot in two mid-altitude tropical maize populations

Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.

Effects of Exogenous Phthalic and Cinnamic Acids on Enzyme Activities and Microbial Community Structures in Rhizosphere Soil of Adzuki Bean

The aim of this study was to find out the effects of exogenous phenolic acids on soil microbes and enzymes in rhizosphere soil of adzuki bean. In the pot experiment of adzuki bean, phthalic and cinnamic acids were added at four concentrations, 0 （control）, 0.1, 1 and 10 mmol/L, to investigate the changes in the mi- croflora and enzyme activities in rhizosphere soil of adzuki bean as well as relations between them. The results showed that both phthalic and cinnamic acids could inhibit the activities of soil enzymes, including catalase, sucrase, phosphatase and urease. Higher concentrations （10 mmol/L） of phthalic and cinnamic acids showed more significant effects. In addition, the application of phthalic and cinnamic acids reduced the populations of bacteria and actinomycetes and significantly increased the population of fungi. Correlations analysis showed that phosphatase activity had an extremely significant positive correlation with bacterial population, a significant positive correlation with actinomycete population, and a significant negative correlation with fungal population. Phthalic and cinnamic acids could result in imbalanced microbe compositions, reduce enzyme activities and present evident allelopathy in rhizosphere soil.

Effect of Combined Application of Humic Acid and Urea on the Wheat Growth and Yield

This paper aims to research the effects of combined application of humic acid and urea on the wheat yield and yield component,and establish rational fertilizer application scheme of wheat. Split plot experiment was adopted. Two types of phosphorus fertilizer( adding humic acid or not) was assigned to the main plot,and four types of top dressing modes( different amount of urea and humic acid urea) were used in subplots. Effects of combined application of humic acid and urea on the wheat yield and yield component were researched. 375 kg / ha ordinary DAP + 150 kg / ha urea was used as base fertilizer; topdressing of 300 kg / ha urea humate could effectively promote the plant height,leaf area coefficient and aboveground dry matter amount. Adding humic acid in urea in topdressing significantly enhanced the wheat yield and economic coefficient of wheat. Adding humic acid in urea in topdressing has better effects of yield increasing than base fertilizer,and can be used for large scale extension.

Evaluation of Comprehensive Performance of Agronomic Traits of Anmai 1241 by Grey Correlation Analysis and Cluster Analysis Methods

The agronomic traits of the new wheat variety Anmai 1241 were comprehensively evaluated,in order to provide comprehensive and objective theoretical basis for further improvement and production utilization of this variety.The winter water production test results of Anmai 1241 in 14 pilot sites of Henan Seed Management Station from 2016 to 2017 were summarized.The comprehensive performance of 11 agronomic traits of Anmai 1241 in different tests sites in Henan Province was evaluated by the grey correlation analysis and clustering analysis methods.The results showed that among the observed values of 11 traits,the variation coefficient,correlation degree and weight of black embryo rate were 181.64%,0.6679 and 0.1051,respectively.The clustering analysis showed that the 11 traits could be divided into 3 groups.The first type of traits(yield,number of grains per ear and 1000-grain weight)and the third group of traits(percentage of earbearing tillers,number of productive tillers and volume weight)belonged to the yield factor traits,and the sum of their weights was 0.5242.Yield and its related factors played an important role in the variety evaluation of Anmai 1241,and the effect of black embryo on yield should be eliminated in variety improvement.

Characteristics of Sources and Sinks of Yugu 18

[Objectives] The study aimed to discuss the high-yield mechanism of Yugu 18.[Methods] The characteristics of sources and sinks of Yugu 18 with high quality, high yield, wide adaptability and multi-resistance to diseases were studied by using Jigu 18 as the control variety.[Results] Yugu 18 was superior in sink capability and the ability to fill sinks. In the filling period, its photosynthetic capacity was strong, and grain-leaf ratio was high. Photosynthetic products had a great contribution to grain filling after flowering, and the coordination between sources and sinks was good.[Conclusions] The research provides theoretical basis for the breeding and cultivation of high-yield foxtail millet.

Current Situation of Table Grape Industry in Henan Province and Development Recommendations

Through the investigation of the current production situation,regional distribution,variety structure,production organization and existing problems of table grapes in Henan Province,this paper conducted an in-depth analysis on the advantages and disadvantages of the development of table grapes industry in Henan Province.In view of the current problems and development trend,it came up with some pertinent recommendations,including transforming the concept of cultivation,adhering to the principle of"high-quality varieties,standardized cultivation,mechanized management,large-scale operation,and diversified market",strengthening brand building,and promote the integrated development of the primary,secondary and tertiary industries,so as to promote the change of table grape industry in Henan Province from"quantitative scale model"to"quality benefit model",and promote its sustainable and high-quality development.