United States Department of Agriculture-Agricultural Research Service Northwest Irrigation and Soils Research Laboratory, Kimberly, ID 83341.
Plant Dis. 2018 May;102(5):932-937. doi: 10.1094/PDIS-10-17-1575-RE. Epub 2018 Mar 9.
Rhizomania caused by Beet necrotic yellow vein virus (BNYVV) is a yield-limiting sugar beet disease that was observed to influence root resistance to freezing in storage. Thus, studies were conducted to gain a better understanding of the influence of BNYVV and freezing on sugar beet roots to improve pile management decisions. Roots from five commercial sugar beet cultivars (one susceptible and four resistant to BNYVV) were produced in fields under high and trace levels of rhizomania pressure and subjected to storage using five temperature regimes ranging from 0 to -4.4°C for 24 h. After cold treatment, eight-root samples were stored in a commercial indoor storage building (set point 1.1°C) for 50 days in 2014 and 57 days in 2015. Internal root temperature, frozen and discolored tissue, and moisture and sucrose loss were evaluated. The air temperature at 0, -1.1, and -2.2°C matched internal root temperature but internal root remained near -2.2°C when air temperature was dropped to -3.3 and -4.4°C. In a susceptible cultivar produced under high rhizomania pressure, the percentage of frozen tissue increased (P < 0.0001) from an average of 0 to 7% at 0, -1.1, and -2.2°C up to 16 to 63% at -3.3°C and 63 to 90% at -4.4°C, depending on year. Roots from the susceptible cultivar produced under low rhizomania pressure and those from the resistant cultivars from both fields only had elevated (P ≤ 0.05) frozen tissue at -4.4°C in 15 of 18 cultivar-year combinations. Frozen tissue was related to discolored tissue (r = 0.91), weight loss (r = 0.12 to 0.28), and sucrose reduction (r = 0.69 to 0.74). Consequently, BNYVV will not only lead to yield and sucrose loss in susceptible sugar beet cultivars but also to more frozen root tissue as temperatures drop below -2.2°C. Based on these observations, the air used to cool roots in nonfrozen sugar beet piles throughout the winter should not drop below -2.2°C to maximize sucrose retention.
由甜菜坏死黄脉病毒（BNYVV）引起的根茎病是一种限制产量的甜菜病害，人们观察到它会影响甜菜根在储存过程中的抗冻能力。因此，开展了研究以更好地了解 BNYVV 和冷冻对甜菜根的影响，从而改善堆垛管理决策。在根茎病高压力和低压力水平下的田间种植了来自五个商业甜菜品种（一个易感品种和四个抗 BNYVV 品种）的根，并在 0 至-4.4°C 的五个温度范围内储存 24 小时。经过冷处理后，在 2014 年和 2015 年，将 8 个根样本储存在一个商业室内储存建筑中（设定点 1.1°C）50 天和 57 天。评估了内部根温、冷冻和变色组织以及水分和蔗糖损失。0°C、-1.1°C 和-2.2°C 的空气温度与内部根温相匹配，但当空气温度降至-3.3°C 和-4.4°C 时，内部根仍接近-2.2°C。在高根茎病压力下生产的易感品种中，冷冻组织的百分比（P < 0.0001）从 0°C 时的平均 0%到 7%增加到-3.3°C 时的 16%到 63%和-4.4°C 时的 63%到 90%，具体取决于年份。在低根茎病压力下生产的易感品种和来自两个田间的抗品种的根在 18 个品种/年份组合中有 15 个组合在-4.4°C 时仅观察到冷冻组织升高（P ≤ 0.05）。冷冻组织与变色组织（r = 0.91）、重量损失（r = 0.12 至 0.28）和蔗糖减少（r = 0.69 至 0.74）相关。因此，BNYVV 不仅会导致易感甜菜品种的产量和蔗糖损失，还会导致温度降至-2.2°C 以下时更多的冷冻根组织。基于这些观察结果，在整个冬季，为了最大限度地保留蔗糖，用于冷却非冷冻甜菜堆中根的空气温度不应降至-2.2°C 以下。
