叶绿素(Chl)含量，尤其是Chl b含量和气孔导度(G_s)是影响净光合速率(P_n)的关键因素。谷子(Setaria italica)是二倍体C₄禾本科植物，基因组简单，转化效率高，已被广泛应用于光合作用和耐旱研究中。本研究对48株EMS诱变的谷子材料进行了Chl含量、G_s以及P_n的表征。发现分别有24、34以及35个突变体材料在Chl含量、G_s以及P_n上发生了显著的变异。相关分析表明，G_s的增加与P_n的增加存在显著正相关关系，Chl b含量的降低与Pn的降低存在弱相关关系。值得注意的是，我们鉴定到两个突变体，Chl b含量显著低于对照豫谷1号，但P_n显著高于豫谷1号。同时，有7个突变体，G_s显著降低于对照，但P_n不显著降低。由此，本研究鉴定了丰富的遗传变异株系，对这些株系对进一步研究将有助于解析Chl含量、G_s和P_n之间的关系，以及C₄物种高效光合和节水的机理

由瘟病菌引起的瘟病造成世界上多种粮食作物严重减产，但是到目前为止，在禾本科作物中，对抗瘟病基因的遗传研究仍然有限。本研究利用888份谷子核心种质资源，在苗期接种谷瘟病菌株HN-1，通过GWAS方法，寻找抗谷瘟病位点。表型鉴定结果表明，谷子种质资源中高抗资源不到1.6%，中抗资源占35.25%，中感资源占57.09%，高感资源占6.08%。通过表型鉴定发现，在地理分布上，谷子生长季降雨量较高的地区高抗资源比例相对较高。利用覆盖谷子全基因组的720 000个SNP标记进行全基因组关联分析，在第2和第9条染色体上找到了2个显著的谷瘟病抗性相关位点，对这2个位点的分析找到了8个可能的抗病候选基因。这些结果为抗谷瘟病遗传育种和相关基因的克隆奠定了基础，也为其他作物抗瘟病育种和相关基础研究提供了指导信息。

    Kernel color is an important trait for assessing the commercial and nutritional quality of foxtail millet.  Yellow pigment content (YPC) and carotenoid components (lutein and zeaxanthin) of 270 foxtail millet accessions, including 50 landraces and 220 improved cultivars, from four different eco-regions in China were surveyed using spectrophotometry and high performance liquid chromatography methods.  Results indicated that YPC had rich variance, ranging from 1.91 to 28.54 mg kg^–1, with an average value of 17.80 mg kg^–1.  The average YPC of improved cultivars (18.31 mg kg^–1) was significantly higher than that of landraces (15.51 mg kg^–1).  The YPC in cultivars from the Loess Plateau spring sowing region (LPSSR) was the highest (20.59 mg kg^–1), followed by the North China summer sowing region (NCSSR, 18.25 mg kg^–1), the northeast spring sowing region (NSSR, 17.25 mg kg^–1), and the Inner Mongolia Plateau spring sowing region (IMPSSR, 13.92 mg kg^–1).  The variation coefficients of YPC in cultivars from NSSR, LPSSR, and IMPSSR were higher than that from NCSSR.  A similar carotenoid profile was also obtained for 270 foxtail millet cultivars.  Lutein and zeaxanthin accounted for approximately 55–65% of YPC in accessions.  The lutein content was higher than zeaxanthin content in all cultivars.  The ratio of lutein to zeaxanthin ranged from 1.51 to 6.06 with an average of 3.34.  YPC was positively correlated with lutein (r=0.935, P<0.01), zeaxanthin (r=0.808, P<0.01), and growth duration (r=0.488, P<0.01), whereas it was negatively correlated with grain protein (r=−0.332, P<0.01) and 1 000-kernel weight (r=−0.153, P<0.05).  Our study is useful for screening and selecting cultivars with high levels of yellow pigment and for enhancing phytochemical concentrations in breeding programs.

Heterosis has contributed greatly to yield in maize, but the nature of its contribution is not completely clear. In this study, two strategies using whole-genome oligonucleotide microarrays were employed to identify differentially expressed genes (DEGs) associated with heterosis and yield. The analysis revealed 1 838 heterosis-associated genes (HAGs), 265 yieldassociated genes (YAGs), and 85 yield heterosis-associated genes (YHAGs). 37.1% of HAGs and 22.4% of YHAGs expressed additively. The remaining genes expressed non-additively, including those with high/low-parent dominance and over/under dominance, which were prevalent in this research. Pathway enrichment analysis and quantitative trait locus (QTL) co-mapping demonstrated that the metabolic pathways for energy and carbohydrates were the two main enriched pathways influencing heterosis and yield. Therefore, the DEGs participating in energy and carbohydrate metabolism were considered to contribute to heterosis and yield significantly. The investigation of potential groups of HAGs, YAGs, and YHAGs might provide valuable information for exploiting heterosis to improve yield in maize breeding. In addition, our results support the view that heterosis is contributed by multiple, complex molecular mechanisms.