Screening Winter Wheat Germplasm for Fusarium Head Blight Resistance

58 winter wheat breeding lines and 4 widely popularized varieties in Huaihe River wheat production regions of Anhui were used to screen resistant germplasms to Fusarium head blight. Incidence, disease index, percentage of infected kernels and DON content in the kernels were measured for each variety or line following artificial inoculation of Fusarium spp. pathogens. Reactions of wheat to Fusarium infection varied among genotypes and different types of resistance. The incidence of infection for each variety or line highly correlated to the severity of colonization after infection. DON content was more correlated to the percentage of kernels infected than to the overall incidence or severity. The selected control varieties were all susceptible to FHB, while seven breeding lines demonstrated good resistant performance. New FHB resistant winter wheat varieties appealing to the actual needs are expected from them.

Impact of Fungicide Treatments on the Constitution of Unsound Wheat Kernels

Nine fungicides were applied,either through seed-dressing or post-anthesis foliar-spray,to eight winter wheat varieties to understand their influences on the constitution of unsound kernels during the 2017-2018 growth season in Funan Experimental Station,Anhui,P.R.China.Three unsound kernel items,i.e.Fusarium-damaged kernels( FDKs),black-germ kernels( BGKs) and pre-harvest sprouted kernels( PHSKs),were measured from the harvested grains.A high percentage of unsound kernels was noticed as 6.00% for FDKs,8.43% for BGKs,and 38.19% for PHSKs due to excessive precipitation during the filling and maturation stages within the season.Fungicide treatments showed positive impacts on the formation of FDKs and BGKs.No significant differences were noticed on the percentage of PHSKs among treatments.The best control efficiency on FDKs,24.63%,was observed in the treatment of‘tebuconazole + prochloraz-manganese chloride complex'.The highest control efficiency on BGKs,31.54%,was achieved by the treatment of‘phenazino-1-carboxylic acid'.Significant differences were noticed among varieties with respect to the constitution of unsound kernels.Under the specific ecological conditions,70%-75% of the final grain quality of wheat was determined by the genotype itself.It was concluded that the genetic resistance or tolerance to relevant fungal pathogens and pre-harvest sprouting was the key factor determining the constitution of unsound wheat kernels,whilst chemical control might function with limited effects when crop was grown under high-pressure or stress conditions.

Screening Fungicides for Controlling Fusarium Head Blight of Winter Wheat

Chemical control of wheat Fusarium head blight(FHB) is emphasized when the genetic resistance in cultivars is insufficient in preventing the crop from disease damage or the crop is under high FHB epidemic pressure. Considering the accumulating resistance to carbendazim in FHB pathogens due to its repeatedly use, alternative fungicides with higher efficacy and safety need to be selected and recommended. In this study, ten fungicides were screened for their efficiencies of controlling FHB on winter wheat in Anhui Province, during 2015-2016 growing season. Fusarium infection, demonstrated both as disease incidence and severity, was positively correlated to the Fusarium-damaged kernels(FDKs) and deoxynivalenol(DON) content in the harvested grains and negatively correlated to the grain yield. Fungicides containing tebuconazole, e.g. phenamacril+tebuconazole, tebuconazole+thiram, prothioconazole+tebuconazole, and thiophanate-methyl+tebuconazole all showed control effects on FHB,especially when those fungicides were sprayed onto the spikes at early anthesis and then a second spray one week later.Phenamacril, though gave no obvious effects on decreasing FHB incidence and severity, performed equally in decreasing the FDKs and DON content to tebuconazole. Those fungicides could be recommended to control wheat FHB, and better to be used alternately in the purpose of avoiding accumulating resistance in the causal pathogens. Biocontrol agent validamycin A +Bacillus cereus endospores also achieved acceptable control efficiency, especially under situations that environmental and food-safety issues were concerned. Difenoconazole +polyoxin B and tetramycin failed to show any advantages in controlling the infection of FHB pathogens.

Yield Gap Analysis of Wheat in Rice-wheat Rotation Regions of Anhui Province,China

The present study was planned to analyze the yield gap of wheat and its production constraints in order to explore the approaches for narrowing the yield gap of wheat in different wheat-rice rotation regions of Anhui Province. The production status and limiting factors of wheat in three rice-wheat rotation regions which are named Region Ⅰ,Region Ⅱ and Region Ⅲ were surveyed by using participatory rural appraisal method. The personnel,who were engaged in wheat production in rice-wheat rotation regions of Anhui Province,mainly ageing from 41 to 60,accounted for 79% of the total personnel in the regions. There were significant differences in yield of wheat which was planted after rice in Anhui. The yield was ranging from 8 907. 00 to 2 700. 00 kg/ha from north to south with an average of 4 978. 5 kg/ha,and the rank of overall average yields at province level was Region Ⅰ( 5 685. 60 kg/ha) > Region Ⅱ( 5 600. 10 kg/ha) > Region Ⅲ( 3 048. 60 kg/ha). The average yield gap of wheat in wheat-rice rotation regions at province level was up to 2 637. 00 kg/ha,and the extreme yield gaps per hectare in the same region were 2 778. 00 kg( Region Ⅰ),2 502. 00 kg( Region Ⅱ) and 1 575. 00 kg( Region Ⅲ) respectively. The objective constraints were Fusarium head blight and pre-harvest sprouting;the subjective constraints were variety selection and layout,poor sowing quality and low seedling quality;social constraints were high cost,low market price and poor efficiency;and ecological constraints were poor soil texture,soil infertility and poor water-and-fertilizer retention. The yield gap of wheat in rice-wheat rotation regions can be effectively reduced by improving yield potential of low-and-medium-yielding fields. Selecting appropriate wheat varieties and layout,constructing disease forecast system,improving agricultural machinery and social service organizations of plant protection,and strengthening scientific training as well as technological training of new agricultural operators and agricultural machinery technicians are the core means to narrowing the yield gap of wheat in rice-wheat rotation regions at province scale.