Lodging is being increasingly recognized as a critical concern among crop breeders worldwide as it causes a significant reduction in the grain yield and quality of multiple cereal crops. The lodging index is frequently used for evaluating the lodging resistance of rice (Oryza sativa L.) crops. However, the application of lodging index for comparing lodging susceptibility between different rice cultivars is inadequate under certain special conditions. This study was aimed to identify optimized parameters that would evaluate the lodging susceptibility and could then be used along with the lodging index for further assessing the lodging resistance. A total of 32 representative rice accessions from different countries were grown at two different locations on three different sowing dates over a period of 3 yr. The analysis of the lodging index of the different rice cultivars revealed the lodging index value of 200 as the critical threshold value of the evaluated rice accessions. Subsequently, an optimized parameter from the lodging index was proposed. This parameter could be interpreted as the magnitude of the external force that the basal second internode could withstand. A comparison of the optimized parameter values of different rice accessions revealed a previously unknown lodging-resistant variety R379. The application of the optimized parameter would enable an accurate determination and comparison of the lodging resistance among different rice cultivars, thereby contributing to the effective selection of lodging-resistant cultivars in rice breeding programs.

中文翻译：

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基于倒伏指数优化参数的水稻抗倒伏性评价

寄宿越来越被世界各地的作物育种者认为是一个关键问题，因为它会导致多种谷类作物的谷物产量和质量显着下降。倒伏指数常用于评价水稻的抗倒伏性。L.) 农作物。然而，在某些特殊条件下，应用倒伏指数比较不同水稻品种间倒伏敏感性是不够的。本研究旨在确定可评估倒伏敏感性的优化参数，然后可与倒伏指数一起用于进一步评估抗倒伏性。在 3 年的时间里，在三个不同的播种日期，在两个不同的地点种植了来自不同国家的 32 个具有代表性的水稻种质。对不同水稻品种的倒伏指数分析表明，倒伏指数值为200作为评价水稻品种的临界阈值。随后，提出了来自倒伏指数的优化参数。该参数可以解释为基底第二节间可以承受的外力的大小。比较不同水稻种质的优化参数值，揭示了一种以前未知的抗倒伏品种 R379。优化参数的应用将能够准确确定和比较不同水稻品种之间的抗倒伏性，从而有助于在水稻育种计划中有效选择抗倒伏品种。