Muoki Chalo Richard, Maritim Tony Kipkoech, Oluoch Wyclife Agumba, Kamunya Samson Machohi, Bore John Kipkoech
Crop Improvement and Management Programme, Kenya Agricultural and Livestock Research Organization, Tea Research Institute, Kericho, Kenya.
Sustainable Ecosystem Management and Conservation Programme, Kenya Agricultural and Livestock Research Organization, Tea Research Institute, Kericho, Kenya.
Front Plant Sci. 2020 Mar 25;11:339. doi: 10.3389/fpls.2020.00339. eCollection 2020.
Climate change triggered by global warming poses a major threat to agricultural systems globally. This phenomenon is characterized by emergence of pests and diseases, extreme weather events, such as prolonged drought, high intensity rains, hailstones and frosts, which are becoming more frequent ultimately impacting negatively to agricultural production including rain-fed tea cultivation. Kenya is predominantly an agricultural based economy, with the tea sector generating about 26% of the total export earnings and about 4% gross domestic product (GDP). In the recent years, however, the country has witnessed unstable trends in tea production associated with climate driven stresses. Toward mitigation and adaptation of climate change, multiple approaches for impact assessment, intensity prediction and adaptation have been advanced in the Kenyan tea sub-sector. Further, pressure on tea breeders to release improved climate-compatible cultivars for the rapidly deteriorating environment has resulted in the adoption of a multi-targeted approach seeking to understand the complex molecular regulatory networks associated with biotic and abiotic stresses adaptation and tolerance in tea. Genetic modeling, a powerful tool that assists in breeding process, has also been adopted for selection of tea cultivars for optimal performance under varying climatic conditions. A range of physiological and biochemical responses known to counteract the effects of environmental stresses in most plants that include lowering the rates of cellular growth and net photosynthesis, stomatal closure, and the accumulation of organic solutes such as sugar alcohols, or osmolytes have been used to support breeding programs through screening of new tea cultivars suitable for changing environment. This review describes simulation models combined with high resolution climate change scenarios required to quantify the relative importance of climate change on tea production. In addition, both biodiversity and ecosystem based approaches are described as a part of an overall adaptation strategy to mitigate adverse effects of climate change on tea in Kenya and gaps highlighted for urgent investigations.
全球变暖引发的气候变化对全球农业系统构成了重大威胁。这种现象的特征是病虫害的出现、极端天气事件，如长期干旱、高强度降雨、冰雹和霜冻，这些事件变得越来越频繁，最终对包括雨养茶种植在内的农业生产产生负面影响。肯尼亚主要是一个以农业为基础的经济体，茶叶部门约占总出口收入的26%，约占国内生产总值(GDP)的4%。然而，近年来，该国茶叶生产出现了不稳定的趋势，这与气候驱动的压力有关。为了缓解和适应气候变化，肯尼亚茶叶子部门提出了多种影响评估、强度预测和适应方法。此外，由于环境迅速恶化，茶叶育种者面临着推出改良的气候适应品种的压力，因此采用了一种多目标方法，试图了解与茶叶生物和非生物胁迫适应及耐受性相关的复杂分子调控网络。遗传建模是一种有助于育种过程的强大工具，也被用于选择在不同气候条件下表现最佳的茶叶品种。一系列已知能抵消大多数植物环境胁迫影响的生理和生化反应，包括降低细胞生长速率和净光合作用、气孔关闭以及糖醇等有机溶质或渗透溶质的积累，已被用于通过筛选适合不断变化环境的新茶叶品种来支持育种计划。这篇综述描述了结合高分辨率气候变化情景的模拟模型，以量化气候变化对茶叶生产的相对重要性。此外，生物多样性和基于生态系统的方法都被描述为整体适应战略的一部分，以减轻气候变化对肯尼亚茶叶的不利影响，并强调了亟待调查的差距。
