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Context: Well-organised leaf architecture produces compact canopies and allows for greater sunlight penetration, higher photosynthetic rates, and thus greater yields. Breeding for enhanced leaf architecture of sorghum (Sorghum bicolor L.), a key food source in semi-arid regions, benefits its overall production. Aims: The study focuses on selecting useful genotypes with excellent leaf architecture for grain sorghum improvement. Methods: In total, 185 sorghum genotypes were subjected to multi-environment trials. Leaf flagging-point length, leaf length, leaf width, leaf angle and leaf orientation value (LOV) were characterised under field conditions. Genotype + genotype × environment interaction (GGE) biplot analysis was used to identify the most stable genotypes with the highest LOV. Key results: Statistical analysis showed significant effects of genotype × environment interaction (P < 0.001), and high broad-sense heritability for the traits. Correlation analysis demonstrated negative correlations (P < 0.001) between LOV and its components. Singular value decomposition of LOVs in the first two principal components explained 89.19% of the total variation. GGE biplot analysis identified G55 as the ideotype with the highest and most stable LOV. Conclusions: Leaf architecture optimisation should be given greater attention. This study has identified a genotype with optimal and stable leaf architecture, laying the foundation for improvement in breeding to increase overall yields of sorghum. Implications: Genotype G55 can be utilised as a parent with other parents that display economically important characteristics in breeding programs to produce offspring that can be planted densely to increase population yields. Genotypes identified with loose leaf architecture are useful in dissecting genes controlling leaf architecture by crossing with G55 to construct genetic mapping populations. Grain sorghum is a food source for people in semi-arid regions; however, its productivity is compromised by its inefficient leaf architecture. Aiming to improve sorghum productivity, the research focused on evaluation of leaf architectural traits and identification of ideotypes with outstanding leaf architecture. Through multi-environment trials, an ideal genotype was selected for best leaf architecture performance, which will be useful as the parental line to optimise sorghum leaf architecture in a breeding program. [ABSTRACT FROM AUTHOR]

The North China Plain (NCP) is an important production base for wheat (Triticum aestivum L.) and maize (Zea mays L.) in China, but intensive continuous winter wheat and summer maize (WM) double-cropping system (control) has also created the high carbon footprint (CF) ecological problems. It is imperative to build a new rotation pattern that not only achieves direct and indirect low greenhouse gases (GHG) emissions, but also takes into account the grain security. CF metrics (per unit area (CF a), per unit economic output (CF e) and per unit kg grain yield (CF y)) were calculated for a two-year crop rotation experiment established at the Wuqiao Experimental Station, from October 2016 to September 2018. The treatments were eight alternative crop sequences grown in the first year, followed by WM in the second year. Alternative crop sequences included (1) WM, (2) fallow, (3) spring maize, (4) winter wheat, (5) spring sweet potato (Dioscorea esculenta (Lour.) Burkill), (6) spring peanut (Arachis hypogaea Linn.), (7) winter wheat-summer peanut, and (8) potato (Solanum tuberosum L.) - silage maize. The results showed that fallow → WM and winter wheat → WM were weak absorption sinks of net GHG, and other rotation patterns were all net sources during the experimental period, while the seven rotation patterns could attain 48%–94% of grain crops yield in control. Spring sweet potato → WM and winter wheat - summer peanut → WM, had no significant differences with control from three different CF perspectives. Spring maize → WM, spring peanut → WM, and potato - silage maize → WM produced more CF than control. Therefore, fallow and planting winter wheat alone in the first year of novel two-year rotation patterns reduced CF in the NCP, planting spring sweet potato and winter wheat-summer peanut increased net income without increasing CF and without compromising grain security, which could attain 1.53 and 1.12 times of the control. The research preliminary showed that winter wheat → WM, spring sweet potato → WM and winter wheat - summer peanut → WM were feasible to trade off of grain production and reducing CF. • Exploring the novel rotation patterns and trying to ensure grain security while reducing carbon emissions. • Compared with winter wheat and summer maize (WM), fallow→WM and W→WM were weak absorption sinks and required fewer resources. • Spring sweet potato→WM and W-summer peanut→WM increased net income, without increasing CF and compromising grain security. [ABSTRACT FROM AUTHOR]