Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.
Better Border Biosecurity (B3), New Zealand.
PLoS One. 2021 Aug 26;16(8):e0256623. doi: 10.1371/journal.pone.0256623. eCollection 2021.
Imports of seeds for sowing are a major pathway for the introduction of contaminant seeds, and many agricultural weeds globally naturalised originally have entered through this pathway. Effective management of this pathway is a significant means of reducing future plant introductions and helps minimise agricultural losses. Using a national border inspection database, we examined the frequency, origin and identity of contaminant seeds within seed for sowing shipments entering New Zealand between 2014-2018. Our analysis looked at 41,610 seed lots across 1,420 crop seed species from over 90 countries. Overall, contamination was rare, occurring in 1.9% of all seed lots. Among the different crop types, the arable category had the lowest percentage of seed lots contaminated (0.5%) and the forage category had the highest (12.6%). Crop seeds Capsicum, Phaseolus and Solanum had the lowest contamination rates (0.0%). Forage crops Medicago (27.3%) and Trifolium (19.8%) had the highest contamination rates. Out of 191 genera recorded as contaminants, Chenopodium was the most common. Regulated quarantine weeds were the rarest contaminant type, only occurring in 0.06% of seed lots. Sorghum halepense was the most common quarantine species and was only found in vegetable seed lots. Vegetable crop seed lots accounted for approximately half of all quarantine species detections, Raphanus sativus being the most contaminated vegetable crop. Larger seed lots were significantly more contaminated and more likely to contain a quarantine species than smaller seed lots. These findings support International Seed Testing Association rules on maximum seed lot weights. Low contamination rates suggest industry practices are effective in minimising contaminant seeds. Considering New Zealand inspects every imported seed lot, utilises a working sample size 5 times larger than International Seed Testing Association rules require, trades crop seed with approximately half of the world's countries and imports thousands of crop seed species, our study provides a unique overview of contaminant seeds that move throughout the seed for sowing system.
进口播种用种子是污染物种子传入的主要途径，目前全球范围内许多农业杂草最初都是通过这种途径传入的。有效管理这一途径是减少未来植物引种的重要手段，有助于减少农业损失。我们利用国家边境检验数据库，研究了 2014-2018 年间进入新西兰的播种用种子货物中污染物种子的频率、来源和种类。我们的分析涉及来自 90 多个国家的 1420 种作物种子的 41610 个种子批。总体而言，污染情况很少见，仅发生在所有种子批的 1.9%中。在不同的作物类型中，耕地作物的种子污染比例最低（0.5%），饲料作物的种子污染比例最高（12.6%）。辣椒（Capsicum）、菜豆（Phaseolus）和茄属植物（Solanum）等作物种子的污染率最低（0.0%）。饲料作物紫花苜蓿（Medicago）和三叶草（Trifolium）的污染率最高（27.3%和 19.8%）。在记录的 191 种污染物属中，藜属（Chenopodium）最为常见。受监管的检疫性杂草是最罕见的污染物类型，仅出现在 0.06%的种子批中。高粱属杂草（Sorghum halepense）是最常见的检疫物种，仅在蔬菜种子批中发现。蔬菜作物种子批约占所有检疫物种检测的一半，萝卜（Raphanus sativus）是受污染最严重的蔬菜作物。较大的种子批比较小的种子批污染更严重，更有可能含有检疫物种。这些发现支持国际种子检验协会关于最大种子批重量的规则。低污染率表明行业实践在最大限度地减少污染物种子方面是有效的。考虑到新西兰对每批进口种子进行检验，使用的工作样本量是国际种子检验协会规则要求的 5 倍，与全球约一半的国家进行作物种子贸易，并进口数千种作物种子，我们的研究提供了对贯穿整个播种用种子系统的污染物种子的独特概述。
