文献类型： 外文期刊

作者： Zhou, Jingyuan ¹ ; Nie, Junjun ¹ ; Kong, Xiangqiang ¹ ; Dai, Jianlong ¹ ; Zhang, Yanjun ¹ ; Zhang, Dongmei ¹ ; Cui, Zhengpeng ¹ ; Hua, Ziqing ¹ ; Li, Zhenhuai ¹ ; Dong, Hezhong ¹ ;

作者机构： 1.Shandong Acad Agr Sci, Inst Ind Crops, Jinan 250100, Shandong, Peoples R China

2.Shandong Normal Univ, Coll Life Sci, Jinan 250014, Shandong, Peoples R China

3.China Agr Univ, Coll Agron, Beijing 100094, Peoples R China

4.Shihezi Univ, Agr Coll, Shihezi 832003, Xinjiang, Peoples R China

关键词： Cotton; Yield stability; Canopy photosynthesis; Assimilate partitioning; Vegetative branch

期刊名称：FIELD CROPS RESEARCH （ 影响因子：5.8； 五年影响因子：6.9 ）

ISSN： 0378-4290

年卷期： 2023 年 303 卷

页码：

收录情况： SCI

摘要： Context: Mechanical monoseeding has been widely adopted in cotton planting; however, it can result in either double seedlings per hole or a decrease in seedling density due to missed seeding or seedling mortality. The impact of these conditions on cotton yield remains uncertain. In this study, we hypothesized that neither double seedlings per hole nor a reduction in seedling density would negatively affect cotton yield. Furthermore, we propose that yield stability can be achieved by manipulating vegetative branching and photoassimilate partitioning. Methods: We conducted two experiments in 2020, 2021 and 2022. The first experiment included a monoseeding treatment, where one seed per hole was sown without seedling thinning after emergence, and a cluster seeding treatment, where ten seeds per hole were sown and one seedling was left after emergence. In the second experiment, a double seedlings per hole (2 S) treatment was set up by sowing ten seeds per hole and leaving two seedlings per hole after thinning, while a one seedling per hole (1 S) treatment with the same plant density served as the control. The growth of vegetative branches (VB), boll-setting on both vegetative and sympodial branches (SB), yield, canopy apparent photosynthesis (CAP), and assimilate partitioning were evaluated. Results: In the first experiment, monoseeding decreased the final plant density by 16.8% compared to cluster seeding, but there was no difference in seedcotton yield between the two treatments. Monoseeding exhibited higher values for VB biomass, number of bolls on VB, and their contribution to yield, indicating improved vegetative branching and VB fruiting, compensating for the yield loss due to plant density reduction. Although monoseeding did not show superiority in terms of leaf area and CAP, it increased photoassimilate partitioning to VB and VB bolls by 1.4 and 2 times compared to cluster seeding, respectively, which played a key role in the improved vegetative branching under monoseeding. In the second experiment, there were no difference in leaf area index, CAP and seedcotton yield between 2 S and 1 S. However, the VB biomass and its percentage to total biomass, the number of bolls on VB an their percentage contribution to yield under 2 S significantly decreased relative to 1 S, indicating inhibited vegetative branching and VB fruiting. Furthermore, the photoassimilate partitioning of 2 S to VB and VB bolls decreased by 32.6% and 29.4% compared with 1 S, but the partitionging to SB and bolls on SB increased by 2.4 and 4.1 times, respectively. Thus, the yield stability was achieved by suppressing vegetative branching while promoting sympodial branching under the 2 S treatment. The expression patterns of phytohormone (IAA, GA and CKs)-related genes and hormone contents in the VB tips were consistent with the observed changes in vegetative branching. Conclusion: This study indicated that the reduced seedling density and double plants per hole caused by monoseeding did not reduce cotton yield, which was achieved through manipulation of photoassimilate partitioning and vegetative branching associated with the expression of phytohormone-related genes and phytohormone levels in VB tips. This study provides a strong evidence in favor of monoseeding, and offers new insights into enhancing yield stability through manipulation of photoassimilate partitioning and branching in cotton.