Kim Tae-Heon, Kim Suk-Man
Institute of Agricultural Science and Technology, Kyungpook National University, Daegu, Republic of Korea.
Department of Crop Science, Kyungpook National University, Sangju, Republic of Korea.
Front Plant Sci. 2024 Oct 21;15:1437371. doi: 10.3389/fpls.2024.1437371. eCollection 2024.
Nitrogen (N) is the most essential element for growth, development, and grain yield determination in crops. However, excessive nitrogen application can result in environmental pollution and greenhouse gas emissions that contribute to climate change. In this study, we used 158 rice genetic resources to evaluate the relationships between the soil and plant analysis development (SPAD) value and grain yield (GY) and its components. The SPAD value ranged between 30.5 and 55.8, with a mean of 41.7 ± 5.3, under normal nitrogen conditions (NN, 9 kg/10a), and between 27.5 and 52.3, with a mean of 38.6 ± 4.8, under low nitrogen conditions (LN, 4.5 kg/10a). Under NN conditions, the SPAD values were in the following order: (43.5 ± 5.8), -type (41.7 ± 2.5), others (41.7 ± 5.2), and (38.3 ± 3.8). By contrast, under LN conditions, the SPAD values were in the following order: -type (40.4 ± 2.1), others (40.1 ± 4.5), (39.6 ± 5.2), and (35.6 ± 3.9). The 158 genetic resources showed no correlation between SPAD and yield. Therefore, the low-decrease rate (LDR) and high-decrease rate (HDR) SPAD groups were selected to reanalyze the relationships between the surveyed traits. The SPAD values were positively correlated with 1000-grain weight (TGW) for both LDR and HDR groups (NN: 0.63, LN: 0.53), However, SPAD and GY were positively correlated only in the LDR group. For TGW, the coefficient of determination ( ) was 20% and 13% under NN and LN conditions, respectively. For GY, values of 32% and 52% were observed under NN and LN conditions, respectively. Genetic resources with higher SPAD values in the LDR group exhibited the highest yield (NN: 1.19 kg/m, LN: 1.04 kg/m) under both NN and LN conditions. In conclusion, we selected 10 genetic resources that exhibited higher GY under both NN and LN conditions with minimal yield reductions. These genetic resources represent valuable breeding materials for nitrogen deficiency adaptation.
氮（N）是作物生长、发育和产量形成过程中最重要的元素。然而，过量施用氮肥会导致环境污染和温室气体排放，进而加剧气候变化。在本研究中，我们利用158份水稻遗传资源评估了土壤与植株分析发展（SPAD）值、籽粒产量（GY）及其构成因素之间的关系。在正常施氮条件（NN，9千克/10公亩）下，SPAD值在30.5至55.8之间，平均值为41.7±5.3；在低氮条件（LN，4.5千克/10公亩）下，SPAD值在27.5至52.3之间，平均值为38.6±4.8。在NN条件下，SPAD值顺序如下：（43.5±5.8）型、（41.7±2.5）型、其他（41.7±5.2）型和（38.3±3.8）型。相比之下，在LN条件下，SPAD值顺序如下：（40.4±2.1）型、其他（40.1±4.5）型、（39.6±5.2）型和（35.6±3.9）型。这158份遗传资源的SPAD值与产量之间无相关性。因此，我们选择了低降幅（LDR）和高降幅（HDR）SPAD组重新分析所测性状之间的关系。LDR组和HDR组的SPAD值均与千粒重（TGW）呈正相关（NN条件下：0.63，LN条件下：0.53）。然而，仅LDR组的SPAD值与GY呈正相关。对于TGW，在NN和LN条件下，决定系数（）分别为20%和13%。对于GY，在NN和LN条件下，决定系数值分别为32%和52%。LDR组中SPAD值较高的遗传资源在NN和LN条件下均表现出最高产量（NN条件下：1.19千克/平方米，LN条件下：1.04千克/平方米）。总之，我们筛选出了10份遗传资源，它们在NN和LN条件下均表现出较高的GY，且产量降幅最小。这些遗传资源是适应缺氮环境的宝贵育种材料。
