Genome Analysis in Wheat Breeding for Disease Resistance

A brief review on the development of wheat germplasm with introduced powdery mildew and scab resistance from Haynaldia villosa Sch. and Leymus racemosus Lam., Roegneria ciliaris (Trin.) Nevski as well as R. kamoji C. Koch respectively was made. In the course of germplasm development, genome analysis by means of chromosome banding, genomic in situ hybridization (GISH) or fluorescence in situ hybridization (FISH), molecular markers, particularly restriction fragment length polymorphism (RFLP) coupled with aneuploid analysis was employed for the purpose of improving breeding efficiency. Potential use of such germplasm in wheat breeding practice, basic studies and some related problems were also discussed.

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.

Deoxynivalenol accumulation and detoxification in cereals and its potential role in wheat-Fusarium graminearum interactions

Deoxynivalenol(DON)is a prominent mycotoxin showing significant accumulation in cereal plants during infection by the phytopathogen Fusarium graminearum.It is a virulence factor that is important in the spread of F.graminearum within cereal heads,and it causes serious yield losses and significant contamination of cereal grains.In recent decades,genetic and genomic studies have facilitated the characterization of the molecular pathways of DON biosynthesis in F.graminearum and the environmental factors that influence DON accumulation.In addition,diverse scab resistance traits related to the repression of DON accumulation in plants have been identified,and experimental studies of wheat–pathogen interactions have contributed to understanding detoxification mechanisms in host plants.The present review illustrates and summarizes the molecular networks of DON mycotoxin production in F.graminearum and the methods of DON detoxification in plants based on the current literature,which provides molecular targets for crop improvement programs.This review also comprehensively discusses recent advances and challenges related to genetic engineering-mediated cultivar improvements to strengthen scab resistance.Furthermore,ongoing advancements in genetic engineering will enable the application of these molecular targets to develop more scab-resistant wheat cultivars with DON detoxification traits.