花生连作种植模式影响花形成和发育的机理研究

连作障碍导致花生严重减产。花生连作种植导致花期时，花的生成和发育不足，其原因尚不清楚。花的形成、发育受到植物营养水平和花微生物群落的影响。因此，我们提出假说认为，连作种植降低花生光合作用和增加花中病原菌侵染，从而降低花中养分水平以及改变花微生物群落，减少花的形成、发育和自花授粉，最终引起荚果数目和产量降低。为了验证上述假说，我们拟统计非连作种植和连作种植花生的花数目和生物量、花粉活性、花病原菌丰度、荚果数量和产量。同时，分析花生光合活性、养分分配状况；采用可培养和不可培养方法分析花微生物群落的差异；分析差异可培养微生物回接对于花生物量和发育的影响，确定花微生物群落改变影响花的生长发育；基于转录组学探讨花营养物质代谢相关基因表达状况，初步探究差异微生物群落形成的原因。本研究试图从花的角度揭示花生连作种植减产的机制，开发新策略来增加花的形成和发育，提高连作种植模式下花生以及其他开花作物的产量。

Continuous cropping obstacle causes serious decline in peanut production. Peanut shows shortage in formation and development of flower under continuous cropping condition, but the underlying mechanisms are still unknown. The formation, growth and development of flower are influenced by plant nutritional state and flower microflora. Herein, we hypothesize that continuous cropping pattern inhibits peanut photosynthesis, increases flower pathogen infection, limits the resource for flower and alters floral microbiota, and thus reduces the formation, growth, development and self-pollination success rate of flower, and ultimately reduces pod formation and yield. To verify our hypothesis, we will measure flower number, biomass, pollen activity, pathogen abundance, pod number and yield. Meanwhile, we will determine the effects of continuous cropping pattern on photosynthesis and carbohydrate partitioning at flowering stage. Furthermore, we will employ microbial culture-dependent and culture-independent methods to determine the difference of flower microbiota and analyse the effects of re-inoculation of differentiated culturable microbes on flowers to determine whether flower microbiota affects the growth and development. In addition, transcriptome analysis will be performed to analysis the expression of genes associated nutrient metabolism to determine the mechanisms for the establishment of differential flower microbiota. Our study will reveal the mechanisms for peanut yield decline under continuous cropping from the aspect of flower. Moreover, our study will also provide a new idea that an improvement of flower formation and development is a promising strategy to increase the yield of peanut and other flowering crop under continuous cropping pattern.