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To identify excellent cultivars resistant to Fusarium head blight (FHB), 104 wheat cultivars were tested by single‐flower inoculation using two prevalent pathogens from 2018 to 2020. Agronomic traits were also investigated. Six FHB‐resistance quantitative trait loci (QTL), Fhb1, Fhb2, Fhb4, Fhb5, Fhb7 and Qfhb.crc‐2D, have been assessed using previously reported DNA markers. A diagnostic marker has been used for Fhb1, and indicative markers linked to the other QTL were used. Results showed that (i) 12 (11.5%) cultivars were resistant to two pathogens in 3 years; among them, 'Shengxuan 6', 'Wanhongbian 759', 'Yunong 903' and 'Yunong 901' had good agronomic traits. (ii) Among cultivars with one resistance QTL, the severities of cultivars carrying Fhb1 and Qfhb.crc‐2D were 2.2 and 2.8, respectively, whereas those of cultivars with Fhb2 or Fhb7 were 3.6. Among cultivars with two resistance QTL, the severities of cultivars with Fhb1 + Fhb4, Fhb1 + Fhb7 and Fhb4 + Fhb5 were 2.2, 3.0 and 3.6, respectively. The severity of five cultivars possessing three or four resistance QTL was below 2.5. Fhb1 and Qfhb.crc‐2D showed better resistance effects than other resistance QTL. [ABSTRACT FROM AUTHOR]

Black point disease is a serious concern in wheat production worldwide. In this study, we aimed to identify the major quantitative trait loci (QTL) for resistance to black point caused by Bipolaris sorokiniana and develop molecular markers for marker-assisted selection (MAS). A recombinant inbred line (RIL) population derived from a cross between PZSCL6 (highly susceptible) and Yuyou1 (moderately resistant) was evaluated for black point resistance at four locations under artificial inoculation with B. sorokiniana. Thirty resistant and 30 susceptible RILs were selected to form resistant and susceptible bulks, respectively, which were genotyped by the wheat 660 K SNP array. Two hundred and four single-nucleotide polymorphisms (SNPs) were identified, among which 41(20.7%), 34 (17.2%), 22 (11.1%), and 22 (11.1%) were located on chromosomes 5A, 5B, 4B, and 5D, respectively. The genetic linkage map for the RIL population was constructed using 150 polymorphic SSR and dCAPS markers. Finally, five QTL were detected on chromosomes 5A, 5B, and 5D, designated QBB.hau-5A, QBB.hau-5B.1, QBB.hau-5B.2, QBB.hau-5D.1, and QBB.hau-5D.2, respectively. All resistance alleles were contributed by the resistant parent Yuyou1. QBB.hau-5D.1 is likely to be a new locus for black point resistance. The markers Xwmc654 and Xgwm174 linked to QBB.hau-5A and QBB.hau-5D.1, respectively, have potential utility in MAS-based breeding. [ABSTRACT FROM AUTHOR]

Barley (Hordeum vulgate) has a much higher content of bioactive substances than wheat (Triticum aestivum). In order to investigate additive and/or synergistic effect(s) on the phytosterol content of barley chromosomes, we used a series of barley chromosome addition lines of common wheat that were produced by normal crossing. In determining the plant sterol levels in 2-week-old seedlings and dry seeds, we found that the level of stigmasterol in the barley chromosome 3 addition (3H) line in the seedlings was 1.5-fold higher than that in the original wheat line and in the other barley chromosome addition lines, but not in the seeds. Simultaneously, we determined the overall expression pattern of genes related to plant sterol biosynthesis in the seedlings of wheat and each addition line to assess the relative expression of each gene in the sterol pathway. Since we elucidated the CYP710A8 (cytochrome P450 subfamily)-encoding sterol C-22 desaturase as a key characteristic for the higher level of stigmasterol, full-length cDNAs of wheat and barley CYP710A8 genes were isolated. These CYP710A8 genes mapped on chromosome 3 in barley (3H) and wheat (3A, 3B, and 3D), and the expression of CYP710A8 genes increased in the 3H addition line, indicating that it is responsible for stigmasterol accumulation. Overexpression of the CYP71OA8 genes in Arabidopsis increased the stigmasterol content but did not alter the total sterol level. Our results provide new insight into the accumulation of bioactive compounds in common wheat and a new approach for assessing plant metabolism profiles. [ABSTRACT FROM AUTHOR]