The contradiction between the supply and demand of edible vegetable oil in China is prominent, and the self-sufficiency rate is less than 35%.  Peanut has a very outstanding status in ensuring the security of edible oil and food.  The emphasis of increasing peanut yield should be the improvement of pod yield per unit area, because the total yield of peanut has not increased as required.  This is attributed to mainly two factors - low increase in the crop productivity and the competition for land for grain and cotton crops.  For traditional double-seed sowing pattern, it is difficult to further increase the peanut yield due to the serious contradiction between populations and individuals and the declining population quality under high-yield conditions.  Single-seed precision sowing was proven to be a new way to increase the economic coefficient (economic yield/biological yield) with the basic stability of the total biomass, which could make plants distribute evenly, reduce the competition among individuals and attain the full production potential of single plant.  In order to reveal the mechanism of increasing peanut yield by single-seed precision sowing, the effects on the ontogenetic development (plant character, physiological characteristic and nutrient utilization) and population structure (population uniformity and photosynthesis, source-sink relationship and yield composition) were systematically expounded.  This study reports establishment of the high-yield cultivation technology system with the key technology of single-seed precision sowing and the supporting technology of fertilizing and management.  We anticipate its wider application for the improvement of peanut yield.

 

The growth and yield of peanut are negatively affected by continuous cropping.  Arbuscular mycorrhizal fungi (AMF) and calcium ions (Ca²⁺) have been used to improve stress resistance in other plants, but little is known about their roles in peanut seedling growth under continuous cropping.  This study investigated the possible roles of the AMF Glomus mosseae combined with exogenous Ca²⁺ in improving the physiological responses of peanut seedlings under continuous cropping.  G. mosseae combined with exogenous Ca²⁺ can enhance plant biomass, Ca²⁺ level, and total chlorophyll content.  Under exogenous Ca²⁺ application, the F_v/F_m in arbuscular mycorrhizal (AM) plant leaves was higher than that in the control plants when they were exposed to high irradiance levels.  The peroxidase, superoxide dismutase, and catalase activities in AM plant leaves also reached their maximums, and accordingly, the malondialdehyde content was the lowest compared to other treatments.  Additionally, root activity, and content of total phenolics and flavonoids were significantly increased in AM plant roots treated by Ca²⁺ compared to either G. mosseae inoculation or Ca²⁺ treatment alone.  Transcription levels of AhCaM, AhCDPK, AhRAM1, and AhRAM2 were significantly improved in AM plant roots under exogenous Ca²⁺ treatment.  This implied that exogenous Ca²⁺ might be involved in the regulation of G. mosseae colonization of peanut plants, and in turn, AM symbiosis might activate the Ca²⁺ signal transduction pathway.  The combination of AMF and Ca²⁺ benefitted plant growth and development under continuous cropping, suggesting that it is a promising method to cope with the stress caused by continuous cropping.