The dynamic changes in agricultural practices have negatively impacted rice cultivation resulting in serious weedy rice (Oryza sativa L.) infestations. In this study, field surveys were conducted at six granaries to evaluate the abundance, spatial-distribution patterns, and morphological characteristics of weedy rice in Peninsular Malaysia. An average of 5.28 plants/m² weedy rice density was recorded, with coverage area that ranged from 29% to 66% and occurrence at >67% frequency. Seed morphological characteristics identified the existence of at least 18 biotypes. A total of 134 weedy rice samples were characterized morphologically, and Principle Component Analysis results showed that these samples are highly diverse and are dispersed across Peninsular Malaysia. These genetically diverse reservoir of weedy rice characteristics present opportunities of exploitation in the future, especially through rice breeding and crop improvement. Weedy rice from Kelantan and Selangor displayed unique clusters in the PCA plot which suggest higher tendencies for environmental adaptation although the influencing factors have yet to be determined. Dispersion studies based on Lloyd patchiness index revealed that more than 50% of surveyed field blocks in five states displayed uniform distribution as opposed to cluster distribution observed in the remaining field blocks. These variations in dispersion suggested that farmers in Peninsular Malaysia employed inconsistent weedy rice management practices in every granary and farm block. Observation of weedy rice infestation pattern via spatial distribution suggested that weed management requires proper coordination of control efforts among farmers to ensure the degree of infestation is maintained under a controlled level.

中文翻译：

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马来西亚半岛杂草稻（Oryza sativa L.）的形态变异、分布及关系

农业实践的动态变化对水稻种植产生了负面影响，导致严重的杂草稻 ( Oryza sativa L.) 侵染。在这项研究中，在六个粮仓进行了实地调查，以评估马来西亚半岛杂草稻的丰度、空间分布模式和形态特征。平均 5.28 株/m ²记录了杂草稻密度，覆盖面积从 29% 到 66% 不等，发生频率 >67%。种子形态特征确定了至少 18 种生物型的存在。共对 134 个杂草稻样品进行了形态学表征，主成分分析结果显示这些样品高度多样化并分散在马来西亚半岛。这些具有遗传多样性的杂草稻特性库为未来的开发提供了机会，特别是通过水稻育种和作物改良。来自吉兰丹和雪兰莪的杂草稻在 PCA 图中显示出独特的集群，这表明环境适应的趋势更高，但影响因素尚未确定。基于劳埃德斑块指数的分散研究表明，五个州超过 50% 的调查田块显示出均匀分布，而不是在其余田块中观察到的集群分布。这些分散的变化表明，马来西亚半岛的农民在每个粮仓和农场街区都采用了不一致的杂草稻管理方法。通过空间分布观察杂草稻的侵染模式表明，杂草管理需要农民之间适当协调控制工作，以确保侵染程度保持在受控水平。这些分散的变化表明，马来西亚半岛的农民在每个粮仓和农场街区都采用了不一致的杂草稻管理方法。通过空间分布观察杂草稻的侵染模式表明，杂草管理需要农民之间适当协调控制工作，以确保侵染程度保持在受控水平。这些分散的变化表明，马来西亚半岛的农民在每个粮仓和农场街区都采用了不一致的杂草稻管理方法。通过空间分布观察杂草稻的侵染模式表明，杂草管理需要农民之间适当协调控制工作，以确保侵染程度保持在受控水平。