赤霉病(Fusarium head blight, FHB)是严重影响小麦产量和品质的主要病害之一，在我国长江中下游地区尤为严重。Fhb1和Fhb2是两个主要抗赤霉病位点。扬麦15 (YM 15) 弱筋品质好，是长江中下游地区最受欢迎的品种之一，但对赤霉病抗性较差。本研究采用分子标记辅助选择(MAS)回交策略，利用Fhb1和Fhb2提高扬麦15的赤霉病抗性。每世代进行农艺性状的筛选。我们成功地选择了7个同时携带Fhb1和Fhb2纯合基因型的渐渗系，它们的赤霉病抗性显著高于背景亲本扬麦15。其中3个渐渗系的农艺性状和品质性状与扬麦15相似。本研究表明，利用分子标记聚合Fhb1和Fhb2可显著提高小麦对赤霉病的抗性。

Allene oxide cyclase (AOC) is one of the most important enzymes in the biosynthetic pathway of the plant hormone jasmonic acid (JA). AOC catalyzes the conversion of allene oxide into 12-oxo-phytodienoic acid (OPDA), a precursor of JA. Using 28K cotton genome array hybridization, an expressed sequence tag (EST; GenBank accession no. ES792958) was investigated that exhibited significant expression differences between lintless-fuzzless XinWX and linted-fuzzless XinFLM isogenic lines during fiber initiation stages. The EST was used to search the Gossypium EST database (http://www.ncbi.nlm.nih.gov/) for corresponding cDNA sequences encoding full-length open reading frames (ORFs). Identified ORFs were confirmed using transcriptional and genomic data. As a result, a novel gene encoding AOC in cotton (Gossypium hirsutum AOC; GenBank accession no. KF383427) was cloned and characterized. The 741-bp GhAOC gene comprises three exons and two introns and encodes a polypeptide of 246 amino acids. Two homologous copies were identified in the tetraploid cotton species G. hirsutum acc. TM-1 and G. barbadense cv. Hai7124, and one copy in the diploid cotton species G. herbaceum and G. raimondii. qRT-PCR showed that the GhAOC transcript was abundant in cotton fiber tissues from 8 to 23 days post anthesis (DPA), and the expression profiles were similar in the two cultivated tetraploid cotton species G. hirsutum acc. TM-1 and G. barbadense cv. Hai7124, with a higher level of transcription in the former. One copy of GhAOC in tetraploid cotton was localized to chromosome 24 (Chr. D8) using the subgenome-specific single nucleotide polymorphism (SNP) marker analysis, which co-localized GhAOC to within 10 cM of a fiber strength quantitative trait locus (QTL) reported previously. GhAOC was highly correlated with fiber quality and strength (P=0.014) in an association analysis, suggesting a possible role in cotton fiber development, especially in secondary cell wall thickening.