钾（K）是一种重要的营养元素，可以提高作物的抗逆性/耐受性。K在抗植物寄生线虫中的应用表明，K处理可以减少线虫病的发生，提高作物产量。然而，K在水稻抗拟禾谷根结线虫（Meloidogyne graminicola）中的研究仍然缺乏。本研究首先用K₂SO₄直接处理线虫，发现K₂SO₄对线虫的死亡率、侵染率以及发育水平无显著影响；接着通过温室盆栽接种，发现0.5 mM K₂SO₄处理水稻后，根中的根结和线虫数量分别下降了57.2±4.4% 和59.2±6.6%，成年雌虫比例（70.9±5.6%）显著低于对照（90.7±5.1%），同时幼虫比例（27.0±6.3%）显著高于对照（6.0±3.2%），而水稻的生长不受影响；统计Pluronic明胶中水稻根尖吸引的线虫数量，发现接种后6小时K₂SO₄处理与清水处理之间并无显著差异；对接种后7天根结中巨细胞的形态、大小和数量进行显微观察，发现两个处理间也不存在显著差异；接着检测根结中胼胝质沉积，发现K₂SO₄处理后其沉积面积增加了67.9%，同时其合成基因OsGSL1和降解基因OsGNS5分别显著上调和下调；另外检测H₂O₂累积发现，接种后8和24 小时K₂SO₄处理的根中H₂O₂含量分别增加了78.2% 和118.7%，同时其合成基因OsRbohB也显著上调；再对水杨酸、茉莉酸、乙烯以及油菜素内酯等信号通路相关基因和病程相关蛋白基因的表达进行定量分析，发现在线虫侵染初期K₂SO₄处理显著上调了某些抗病相关基因的表达；最后对K通道基因OsAKT1和转运蛋白基因OsHAK5缺陷型植株进行接种，发现根结和线虫数量显著增加并且线虫的发育加快，同时K₂SO₄的作用降低。这些说明K₂SO₄通过激发基础防御反应提高了水稻对线虫的抗性，并且K通道和转运蛋白积极参与了寄主抗性。K及其通道和转运蛋白在寄主抗性中的应用，为进一步研究水稻抗线虫机制以及钾在植物抗生物胁迫中的功能奠定了基础。低钾能诱导水稻对拟禾谷根结线虫的抗性，为田间有效利用钾肥防控线虫病害提供了理论依据。

大豆孢囊线虫（SCN, Heterodera glycines）严重制约大豆生产。大豆抗线虫数量性状遗传位点Rhg4上的丝氨酸羟甲基转移酶编码基因（GmSHMT08）对大豆孢囊线虫有显著的抗性，但该基因如何介导了对大豆孢囊线虫的抗性机制仍不明晰，GmSHMT08能否与大豆孢囊线虫产生的蛋白发生互作仍不明确。本研究以GmSHMT08作为诱饵，通过酵母双杂交体系在线虫中筛选出了与GmSHMT08互作的一个热休克蛋白70片段（HgHSP70p）。通过GST pull-down和荧光双分子互补，进一步验证了HgHSP70p与GmSHMT08之间存在互作关系。本研究发现的HgHSP70基因可以作为关键候选基因，用于进一步探究GmSHMT08介导的对大豆孢囊线虫的抗性机制。

条形柄锈菌小麦专化型侵染小麦引起条锈病。小麦条锈菌是转主寄生菌，以小麦作为主要寄主完成夏孢子与冬孢子阶段，以小檗作为主要转主寄主完成性孢子与锈孢子阶段。目前，研究报道40余种小檗可作为小麦条锈菌的转主寄，其中大多数是中国小檗种类。然而，有关西南地区云贵高原小檗种类和地理分布知之甚少。云贵高原是中国小麦条锈菌进化相对独立的重要流行区，小麦条锈病在该地区可完成周年循环。本研究中，本文作者对云贵地区的小檗进行了调查，并通过人工接种鉴定了8种小檗可作为小麦条锈菌转主寄主，包括豪猪刺、永思小檗、巴东小檗、金花小檗、古宗金花小檗、滇西北小檗、鳞叶小檗、粉叶小檗,这是首次报道这些小檗种类可作为小麦条锈菌转主寄主。

荔枝在亚热带地区广泛种植，具有重要的经济价值。高密度遗传图谱构建和相关数量性状基因座（QTL）定位是分子标记辅助育种的前提。本研究利用矮化荔枝品种‘紫娘喜’和乔化荔枝品种‘妃子笑’之间的178个子代F₁群体为材料，采用基因分型测序（GBS）技术构建基于单核苷酸多态性（SNP）的高密度连锁图谱。遗传图谱包含3027个SNP标记，分布在15个连锁群上，总的遗传距离为1711.97 cM，平均遗传距离为0.57 cM。基于此高密度遗传图谱和三年的表型分析，共检测到37个QTL与8个矮化性状相关，包括枝梢长度（LNB）、枝梢直径（DNB）、复叶柄长度（LCP）、复叶柄直径（DCP）、节间长度（LI）、叶片长度（LSL）、叶片宽度（WSL）和株高（PH）。这些QTL可以解释8.0％至14.7％（平均= 9.7％）的表型变异。其中，发现几个QTL簇，特别是在LG04和LG11连锁群上，暗示调节荔枝矮化性状的基因可能成簇分布。在这些QTL区间鉴定到126个候选基因，其中55个基因在‘紫娘喜’和‘妃子笑’之间的表达存在差异。这些差异表达基因（DEGs）参与细胞发育、物质运输、信号转导和植物形态发生的调控，可能在调控植物矮化性状中起重要作用。高密度遗传图谱构建及矮化性状相关QTLs分析将为荔枝分子标记辅助育种奠定坚实的基础。

Rice (Oryza sativa L.), a tropical and subtropical crop, is susceptible to low temperature stress during seedling, booting, and flowering stages, which leads to lower grain quality levels and decreasing rice yields. Cold tolerance is affected by multiple genetic factors in rice, and the complex genetic mechanisms associated with chilling stress tolerance remain unclear. Here, we detected seven quantitative trait loci (QTLs) for cold tolerance at booting stage and identified one cold tolerant line, SIL157, in an introgression line population derived from a cross between the indica variety Guichao 2, as the recipient, and Dongxiang common wild rice, as the donor. When compared with Guichao 2, SIL157 showed a stronger cold tolerance during different growth stages. Through an integrated strategy that combined QTL-mapping with expression profile analysis, six candidate genes, which were up-regulated under chilling stress at the seedling and booting developmental stages, were studied. The results may help in understanding cold tolerance mechanisms and in using beneficial alleles from wild rice to improve the cold tolerance of rice cultivars through molecular marker-assisted selection.

Improving the yield of maize grain per unit area is needed to meet the growing demand for it in China, where the availability of fertile land is very limited. Modified fertilization management and planting density are efficient methods for increasing crop yield. Field experiments were designed to investigate the influence of modified fertilization management and planting density on grain yield and nitrogen use efficiency of the popular maize variety Zhengdan 958, in four treatments including local farmer’s practice (FP), high-yielding and high efficiency cultivation (HH), super high-yielding cultivation (SH), and the control (CK). Trials were conducted in three locations of the Huang-Huai-Hai Plain in northern China. Compared with FP, SH was clearly able to promote N absorption and dry matter accumulation in post-anthesis, and achieve high yield and N use efficiency by increasing planting density and postponing the supplementary application of fertilizers. However, with an increase in planting density, the demand of N increased along with grain yield. Due to the input of too much N fertilizer, the efficiency of N use in SH was low. Applying less total N, ameliorating cultivation and cropping management practices should be considered as priority strategies to augment production potential and finally achieve synchronization between high yield and high N efficiency in fertile soils. However, in situations where soil fertility is low, achieving high yield and high N use efficiency in maize will likely depend on increased planting density and appropriate application of supplementary fertilizers postpone to the grain-filling stage.