2020-01-31

封面图展示的焦点合成照片是1只趴在蜜蜂腹部上的瓦螨。瓦螨是危害蜜蜂群体的主要害虫，它会寄生在蜜蜂体内，并且传播病毒性疾病。研究人员已经通过基因工程改造了蜜蜂的细菌肠道共生体，从而杀死这些螨虫，并增强蜜蜂对RNA病毒的抵抗力，这种方法最终可能会有助于蜜蜂的健康。

Focus-stacked photograph of a Varroa mite on the abdomen of a honey bee. Varroa mites are major pests that weaken honey bee colonies by parasitizing bees and spreading viral disease. Researchers have genetically engineered bacterial gut symbionts of bees to kill these mites and boost bee resistance to RNA viruses, an approach that may eventually support honey bee health.

2020-02-07

封面图展示的是中国广西的水稻梯田。通过在绿色改良水稻的种植中使用氮肥，增加了每个植株的开花枝数，从而提高了粮食产量。目前，研究人员已经发现了这种会对氮元素起反应促进分枝的基因。今后的育种工作将重点利用自然基因变异增加粮食产量并减少肥料的需求，从而促进农业的可持续性发展。

Rice paddy terraces in Guangxi, China. The nitrogen fertilizers used in green revolution rice cultivation increase the number of flowering branches per plant, in turn enhancing grain yield. Researchers have now discovered the gene that promotes this branching response to nitrogen. Future breeding efforts will use natural gene variants to increase grain yield and reduce fertilizer need, thus boosting agricultural sustainability.

2020-02-14

封面图展示的是一条滑腻的绿鹦鹉蛇捕食了一只青蛙。在一种真菌病原体导致两栖动物大量死亡后，以此为主要食物来源的热带蛇多样性不断下降。蛇类通常比较罕见，而且很难被发现，但是据研究人员估计，可能性更高的情况是现在蛇类的种族群落更小、更均匀，许多种类的出现率更低，身体条件更差。

A satiny parrot snake (Leptophis depressirostris) preys on a frog. Tropical snake diversity declined after a fungal pathogen led to mass mortality of amphibians, a key food source. Snakes are generally rare and difficult to detect, but researchers estimate a high probability that the snake community is now smaller and more homogeneous, with lower occurrence rates and poorer body conditions for many species.

2020-02-21

封面图展示的是一株北美金缕梅，花被冰冻在了深冬的暴风雪中。气候变化对生物系统的影响在冬季尤为明显。关于冬季生物学的高登研究会议将于2020年6月21—26日在美国新罕布什尔州的沃特维尔谷举行。

American witch hazel (Hamamelis virginiana) flowers encased in ice from a late winter storm. The effects of climate change on biological systems may be especially pronounced in winter. The Gordon Research Conference on the Biology of Winter will be held from 21 to 26 June 2020 in Waterville Valley, New Hampshire.