2015-2017年连续2个生长季，选择西南地区广泛使用的小麦品种9个进行源库关系分析，其中3个具有不同株型品种进行花后源库操作处理：对照（Ct）、去除旗叶和倒二叶（Lr）和去除一侧小穗（Sr），设置2个施氮水平（N+, 150 kg ha^-1; N-, 60 kg ha^-1），研究两种氮水平下不同品种在冠层水平和单株水平上的源库关系。结果表明，Lr显著降低了3个品种的单粒重，而Sr使单粒重显著增加，表明小麦产量潜力在灌浆期受源限制较大，但源库平衡明显受气候变化和氮素亏缺的影响。籽粒产量与库容量（SICA）、粒数、生物量、SPAD值和叶面积指数呈显著正相关关系，表明源限制程度随着SICA的增加而增加。因此，当SICA增加时，育种家应更加关注源限制的影响，尤其在环境较好的条件下。川麦104属半紧凑型品种，穗子大小适中、上部叶片狭长，在源库平衡关系中表现较好，因为川麦104在Lr后籽粒重降幅小、Sr后籽粒重增幅大；花后干物质积累减少幅度最低、源库操作后灌浆期的光合产物向籽粒转移最多。

   Good crop stand establishment and root system development are essential for optimum grain yield of dryland wheat (Triticum aestivum L.). At present, little is known about the effect of tillage and straw mulch on the root system of wheat under dryland areas in southwestern China. The aim of this study was to evaluate the effect of three tillage treatments (no-till, NT; rotary till, RT; conventional till, CT) and two crop residue management practices (straw mulch, ML; non-straw mulch, NML) on stand establishment, root growth and grain yield of wheat. NT resulted in lower soil cover thickness for the wheat seed, higher number of uncovered seeds, lower percentage of seedling-less ridges and lower tiller density compared to RT and CT; ML resulted in higher tiller density compared to NML. Straw mulching resulted in more soil water content and root length density (RLD) at most of the growth stages and soil depths. The maximum RLD, root surface area density and root dry matter density were obtained under NT. In the topmost 10 cm soil layer, higher RLD values were found under NT than those under RT and CT. There were no significant differences in the yield or yield components of wheat among the tillage treatments in 2011–2012, but NT resulted in a significant higher yield compared to RT and CT in 2012–2013. Grain yield was significantly higher in ML compared to in NML. A strong relationship was observed between the water-use efficiency and the grain yield. Both NT and ML proved beneficial for wheat in term of maintaining higher tiller density, better soil water status and root growth, leading to a higher grain yield and enhanced water-use efficiency, especially in a low rainfall year.

Synthetic hexaploid wheat (SHW) represents a valuable source of new resistances to a range of biotic and abiotic stresses. A recombinant inbred line (RIL) population with 127 recombinant inbred lines derived from a SHW-derived variety Chuanmai 42 crossing with a Chinese spring wheat variety Chuannong 16 was used to map QTLs for agronomic traits including grain yield, grains per square meter, thousand-kernel weight, spikes per square meter, grain number per spike, grains weight per spike, and biomass yield. The population was genotyped using 184 simple-sequence repeat (SSR) markers and 34 sequence-related amplified polymorphism (SRAP) markers. Of 76 QTLs (LOD>2.5) identified, 42 were found to have a positive effect from Chuanmai 42. The QTL QGy.saas-4D.2 associated with grain yield on chromosome 4D was detected in four of the six environments and the combined analysis, and the mean yield, across six environments, of individuals carrying the Chuanmai 42 allele at this locus was 8.9% higher than that of those lines carrying the Chuannong 16 allele. Seven clusters of the yield-coincident QTLs were detected on 1A, 4A, 3B, 5B, 4D, and 7D.