Foliar manganese in the health and lignin quality of conventional and glyphosateresistant soybean seeds

Manganese may be associated with plant resistance to fungi, either through lignification or direct inhibition. The aim of this study was to evaluate the foliar application of Mn on the incidence of fungi and the levels of Mn and lignin in soybean seeds from conventional cultivars and their transgenic glyphosate-resistant derivatives (RR). The test was conducted at the Federal University of Lavras, in the state of Minas Gerais, Brazil, using a randomized block design with three replications in a 4 x 4 x 2 factorial scheme, comprising four soybean cultivars, two conventional and their RR derivatives (BRS Celeste and BRS Baliza RR; BRSGO Jataí and BRS Silvânia RR), four foliar dosages of Mn (0, 200, 400 and 600 g Mn ha-1) and two application stages (R1 and R3). Prior to, and after six months of storage, the seeds were subjected to a health test (Blotter test). The levels of Mn in the seeds and lignin in the seed coat were determined. It was found that foliar application of manganese affords a lower incidence of Cercospora kikuchii, Fusarium spp. and Aspergillus spp. in the soybean seeds produced. Foliar applications of Mn in the soybean, both at the R1 and R3 stages, translocates to the seeds, but does not affect lignin production in the seed coat. Levels of lignin in the seed coat of the soybean are lower in the conventional cultivars, Celeste and Jataí, in relation to their transgenic glyphosate-resistant derivatives, Baliza RR and Silvânia RR.

锰可通过木质化作用或直接抑菌作用，与植物的抗真菌抗性相关联。本研究旨在评估叶面施用锰肥对大豆真菌侵染率的影响，以及常规大豆品种及其抗草甘膦转基因衍生品种（RR）的种子中锰与木质素含量。本试验于巴西米纳斯吉拉斯州拉夫拉斯联邦大学开展，采用随机区组设计，设置4×4×2因子试验方案，共3次重复，处理组合涵盖4个大豆品种（2个常规品种及其对应的RR衍生品种：BRS Celeste与BRS Baliza RR；BRSGO Jataí与BRS Silvânia RR）、4个锰肥叶面施用量梯度：每公顷0克、200克、400克及600克锰，以及2个施用时期（R1期与R3期）。在贮藏前及贮藏6个月后，对种子开展吸胀纸床检测法（Blotter test）进行健康检验。本研究同时测定了种子中的锰含量与种皮的木质素含量。研究结果表明，叶面施用锰肥可降低所生产大豆种子中菊池尾孢（Cercospora kikuchii）、镰孢菌属（Fusarium spp.）与曲霉属（Aspergillus spp.）的侵染率。在R1或R3期对大豆进行叶面施锰，锰元素均可转运至种子中，但不会影响种皮的木质素合成。相较于其对应的抗草甘膦转基因衍生品种Baliza RR与Silvânia RR，常规品种Celeste与Jataí的种皮木质素含量更低。