Department of Plant Pathology, Kansas State University, Manhattan 66506.
Department of Agronomy, Kansas State University.
Plant Dis. 2017 Dec;101(12):2059-2065. doi: 10.1094/PDIS-02-17-0238-RE. Epub 2017 Sep 21.
Stalk rot diseases are among the most ubiquitous and damaging fungal diseases of sorghum (Sorghum bicolor (L.) Moench) worldwide. Although reports of quantitative yield losses to stalk rots are available, the impact of stalk rot on grain quality attributes is unknown. This study was conducted to test whether stalk rot diseases could affect grain mineral (N, P, K; Ca, Mg, Cu, Fe, Mn, and Zn) and macronutrient (protein, fat, and starch) content, ash content, and physical traits (unit grain weight, hardness, and diameter). A field experiment was conducted in 2013 and 2014 with four sorghum genotypes (two hybrids and two lines). Plants from each genotype were inoculated with four stalk rot pathogens (Fusarium andiyazi, F. proliferatum, F. thapsinum, and Macrophomina phaseolina) and mock-inoculated with phosphate-buffered saline (control). Grains collected from infected and control plants were analyzed for macronutrient and ash content using near-infrared reflectance spectroscopy, grain hardness and diameter using the single-kernel characterization system, and mineral content using the Rapid Flow Analyzer (Model RFA-300 for N) and inductively coupled plasma spectrometer (for P, K, Ca, Mg, Cu, Fe, Mn, and Zn). Although stalk rot pathogens significantly reduced unit grain weight, they did not significantly affect grain hardness and diameter and, therefore, may not affect milling quality. Pathogens significantly reduced all macronutrient and most mineral contents across genotypes and environments on a per-unit-grain basis, except N and Mg, which were affected in a genotype- and environment-specific manner, and Fe, which was not significantly affected. Most minerals tested were significantly and negatively correlated with disease severity (lesion length) and total grain weight per panicle. The hybrid tested (Pioneer 84G62) exhibited reduced mineral and macronutritional changes after stalk rot infection, providing insights into the possibility of producing high-yielding, nutritionally stable hybrids under stalk rot disease pressure through dedicated breeding efforts.
茎腐病是世界范围内高粱（Sorghum bicolor（L.）Moench）最普遍和最具破坏性的真菌病害之一。尽管有关于茎腐病导致的定量产量损失的报道，但茎腐病对谷物品质属性的影响尚不清楚。本研究旨在测试茎腐病是否会影响谷物的矿物质（N、P、K；Ca、Mg、Cu、Fe、Mn 和 Zn）和大量营养素（蛋白质、脂肪和淀粉）含量、灰分含量以及物理特性（单位粒重、硬度和直径）。2013 年和 2014 年进行了一项田间试验，涉及四个高粱基因型（两个杂交种和两个品系）。每个基因型的植物都用四种茎腐病病原体（Fusarium andiyazi、F. proliferatum、F. thapsinum 和 Macrophomina phaseolina）接种和用磷酸盐缓冲盐水（对照）模拟接种。从感染和对照植物中收集的谷物，使用近红外反射光谱法分析大量营养素和灰分含量，使用单粒特性系统分析谷物硬度和直径，使用 Rapid Flow Analyzer（用于 N 的 Model RFA-300）和电感耦合等离子体光谱仪（用于 P、K、Ca、Mg、Cu、Fe、Mn 和 Zn）分析矿物质含量。尽管茎腐病病原体显著降低了单位粒重，但它们对谷物硬度和直径没有显著影响，因此可能不会影响碾磨质量。病原体显著降低了每个基因型和环境中所有大量营养素和大多数矿物质的含量，除了 N 和 Mg，它们以基因型和环境特异性的方式受到影响，以及 Fe，它没有受到显著影响。测试的大多数矿物质与疾病严重程度（病变长度）和每穗总粒重呈显著负相关。测试的杂交种（Pioneer 84G62）在感染茎腐病后表现出矿物质和大量营养素变化减少，这为通过专门的选育工作在茎腐病压力下生产高产、营养稳定的杂交种提供了思路。
