Influence of Meloidogyne incognita race 1 on the development of clones of Coffea canephora, variety “Jequitibá Incaper 8122”

ABSTRACT: Root-knot nematode is one of the most important phytosanitary problems for Conilon coffee, as it reduces productivity and is difficult to handle. We aimed at studying the infectivity and damage caused by M. incognita race 1 in the “Jequitibá Incaper 8122” intermediate maturity coffee variety. The experiment was conducted in a greenhouse, in completely randomized design, with five replicates. The clones composing the variety “Jequitibá Incaper 8122” were inoculated with 2,000 eggs + second-stage juveniles of M. incognita race 1. Uninoculated plants were the control. Evaluations were performed 180 days after inoculation, considering the plant height (H), stem diameter (SD), number of leaves (NOL), leaf area (LA), number of plagiotropic branches (NPB), number of nodes (NN), chlorophyll content (CHLO), shoot dry matter (SDM), root fresh matter (RFM), final population (FNP), and reproduction factor (NRF). The nematode reduced NOL in clones 208 and 209, NRF in clones 201, 203, 207 and 208, NN in clones 203, 207, 208 and 209, CHLO in clones 201, 204, 206, 207 and 209, SDM in clones 201, 203, 204 and 205 and RFM in clones 205 and 207. M. incognita race 1 FNP and NRF were larger in clones 208, 201, 207 and 203. Clone 202 had FNP and NRF equal to zero, being immune to the nematode. Clone 206 presented the lowest NRF value among clones parasitized by M. incognita.

摘要：根结线虫（Root-knot nematode）是影响科尼隆咖啡（Conilon coffee）的最重要植物检疫性问题之一，其不仅会降低咖啡产量，且防控难度极大。本研究旨在探究南方根结线虫1号小种（M. incognita race 1）对中熟咖啡品种"Jequitibá Incaper 8122"的侵染性与致病危害。试验于温室中开展，采用完全随机设计，设置5次重复。将"Jequitibá Incaper 8122"品种的无性系接种2000个南方根结线虫1号小种的卵与2龄幼虫，以未接种的植株作为空白对照组。于接种后180天开展指标测定，所测指标包括株高（plant height, H）、茎粗（stem diameter, SD）、叶片数（number of leaves, NOL）、叶面积（leaf area, LA）、斜生枝数（number of plagiotropic branches, NPB）、节数（number of nodes, NN）、叶绿素含量（chlorophyll content, CHLO）、地上部干物质重量（shoot dry matter, SDM）、根系鲜重（root fresh matter, RFM）、最终种群数量（final population, FNP）及繁殖系数（reproduction factor, NRF）。结果表明，该线虫可降低208、209号无性系的叶片数，降低201、203、207、208号无性系的繁殖系数，降低203、207、208、209号无性系的节数，降低201、204、206、207、209号无性系的叶绿素含量，降低201、203、204、205号无性系的地上部干物质重量，以及降低205、207号无性系的根系鲜重。南方根结线虫1号小种的最终种群数量与繁殖系数在208、201、207、203号无性系中相对更高。202号无性系的最终种群数量与繁殖系数均为0，对该线虫表现为免疫。在被南方根结线虫侵染的无性系中，206号无性系的繁殖系数最低。