秸秆还田是土壤有机碳（SOC）固定和作物产量稳定性提高的有效策略。然而，在小麦（Triticum aestivum L.）-棉花（Gossypium hirsutum L.）轮作制度下，作物可持续生产的最佳秸秆还田策略仍不明确。本研究的目的是在长江流域小麦-棉花种植制度下，量化长期（10年）碳投入对土壤有机碳固定、团聚体形成和作物产量的影响。采用单因素随机设计，共计5个处理：无秸秆还田（对照）、小麦秸秆还田（Wt）、棉花秸秆还田（Ct）、50%小麦和50%棉秸秆还田（Wh-Ch）以及100%小麦和100%棉秸秆还田。与对照相比，秸秆还田下SOC含量增加了8.4~20.2%。SOC固定与C投入（1.42-7.19 Mg ha⁻¹ yr⁻¹）（P<0.05）之间呈显著的线性正相关关系。秸秆还田也显著提高了0~20 cm土壤>2与1~2 mm团聚体的比例，且以Wt-Ct处理的团聚体水稳性增幅最大（28.1%）。小麦、棉花平均产量分别提高12.4~36.0%和29.4~73.7%，且C投入与小麦和棉花产量之间均存在显著的线性正相关关系。当C投入为7.08 Mg ha⁻¹ yr⁻¹时，可持续产量指数（SYI）均值达到最大值(0.69)，这与Wt-Ct处理的最大SYI值相当（SYI为0.69，C投入为7.19 Mg ha^–1 yr^-1）。综上，小麦和棉花秸秆的全量还田是促进麦棉轮作下有机碳固定、土壤团聚体形成、产量及其可持续性的最佳策略。

Two genetic linkage maps, constructed by DH and RILs populations derived from the same parents, were carried out for the identification and comparison of QTLs controlling yield traits across different years in rice (Oryza sativa L.). A total of 194 SSR and STS markers were used in two maps, of which 114 markers were same. The distribution of Samgang allele was higher in RILs population than it in DH population. Comparing with DH population, RILs population has more lines with higher yield and wider phenotypic transgressive segression for yield traits. Although most of QTLs for the same trait were different in two populations across different years, 8 QTLs (including gwp11.1, spp5.1, spp10.1, spp11.2, ssr1.1, ssr11.1, tgw9.1 and tgw11.1) were detected over 2 yr. It is important to note that ppp10.1, spp10.1 and tgw9.1 were identified in two populations, while spp10.1 and tgw9.1 were simultaneity observed across different years. Epistatic effects were more important than additive effects for PPP, SPP, yield in DH population and TGW, yield in RILs population. Epistatic effects of DH and RILs populations were different on the same genetic background in the present study, which illuminated the QE interaction played an important role on epistatic effect. Identification and comparison of QTLs for yield traits in DH and RILs populations should provide various and more precise information. The QTLs identified in present study would be valuable in marker-assisted selection program for improving rice yield.