Table_2_Diversity in Fruit Morphology and Nutritional Composition of Juglans mandshurica Maxim in Northeast China.XLSX

Although Manchurian walnut (Juglans mandshurica Maxim) is widely distributed in northeast China, very few studies had been reported on its diversity among different populations. We surveyed 12 J. mandshurica populations in their native habitats across the northeast region of China and profiled 13 fruit morphological traits. We found a large degree of variations for these traits, especially for fruit weight (coefficient of variation, or CV of 22.00%), nut weight (CV of 19.42%), and kernel weight (CV of 19.89%). Statistical analysis showed that a large portion of the total variation can be attributed to within-population variation (66.64%), followed by random error (20.96%). We also comprehensively quantified the nutritional composition including fatty acids, amino acids, vitamins, and micronutrients. Similar to fruit morphological traits, we found large variation for most kernel components, which mostly can be explained by within-population variation. Further correlation analysis revealed the dependence of some morphological and nutritional traits on key geographical and ecological factors such as latitude, accumulated temperature, and day length. For instance, a significant positive correlation was found between fruit dimensions and equivalent latitude and precipitation, indicating that such factors should be considered for breeding. Taken together, our data provided a rich dataset for characterizing the variation among J. mandshurica populations and a foundation for selective breeding.

尽管胡桃楸（Manchurian walnut, Juglans mandshurica Maxim）在我国东北地区广泛分布，但针对其不同种群间多样性的研究却极为匮乏。本研究于中国东北地区的原生栖息地中调研了12个胡桃楸种群，并对13项果实形态性状进行了表征分析。研究发现，这些性状存在显著的变异程度，其中尤以果实质量（变异系数CV为22.00%）、果壳质量（CV为19.42%）以及种仁质量（CV为19.89%）的变异最为突出。统计学分析表明，总变异的绝大部分来自种群内变异（占比66.64%），其次为随机误差（占比20.96%）。本研究还对胡桃楸种仁的营养成分进行了全面定量分析，涵盖脂肪酸、氨基酸、维生素及微量营养素等类别。与果实形态性状的结果类似，多数种仁营养组分同样存在较大变异，且此类变异同样主要源于种群内差异。进一步的相关性分析显示，部分形态及营养性状与纬度、积温、日照时长等关键地理与生态因子存在显著关联。例如，果实尺寸与等效纬度及降水量呈显著正相关，这提示在胡桃楸的遗传育种工作中需将此类因子纳入考量范畴。综上，本研究所得数据为解析胡桃楸种群间的性状变异提供了丰富的数据集，同时也为其定向选育奠定了坚实基础。